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Öğe Clinicopathological evaluation of disseminated metastases of transmissible venereal tumor in a spayed bitch(Universidade Federal do Rio Grande do Sul, 2017) Alkan, Hasan; Satilmis, Fatma; Alcigir, Mehmet Eray; Kivrak, Mehmet Bugra; Aydin, IbrahimBackground: Although transmissible venereal tumor (TVT, transmissible venereal sarcoma, Sticker’s sarcoma) that affects dogs and other canids can be seen in many countries, it especially emerges in the countries which homeless dog population is very high. Female dogs are more susceptible than males. Transmissible venereal tumor is usually transmitted to genital organs during coitus and occasionally by social behavior such as sniffing and licking. The tumor is generally observed in the posterior part of the vagina. The tumor usually appears in various sizes, in the appearance of cauliflower, red and fragile. Metastases are rarely reported in cases with TVT. Metastases have been detected in lung, liver, tonsils, skin, lymph nodes, muscles, spleen. The diagnosis of transmissible venereal tumor is achived by considering the history of the animal, gross lesions, cytological examination and histopathology. Chemotherapy is frequently used in the treatment of TVT. In addition, radiotherapy, cryosurgery, surgical incision and immunotherapy are rarely applied for treatment. Chemical agents such as doxorubicin, vincristine sulfate, cyclophosphamide, methotrexate are preferred for chemotherapy. Case: Metastases to all mammary lobes, cervix uteri, neck, skin, gluteal muscles, the oropharyngeal region, and primary vaginal mass were described in spayed bitch, a 10-year old and mixed breed. The clinical examination manifested, fragile and hemorrhagic masses which resemble cauliflower in the vagina, neck, and inguinal region. Furthermore firm and multilobular masses in all mammary lobes, oropharyngeal region, and gluteal muscles of right leg were detected. Firstly, vaginal cytology was performed in order to confirm. In vaginal cytology, round to polyhedral shaped transmissible venereal tumor cells including cytoplasmic vacuoles and polychromatic nuclei were identified. Histopathologically, solid areas included oval- to round-shaped cells with prominent, hyperchromatic nuclei in all masses. Also, some of them comprised mitotic figures in their nuclei. In general, the tumor cells were separated by thin fibrous septa. Additionally, the cells were completely infiltrated to the mammary gland. In contrast, oropharyngeal and subdermal region of neck consisted more solid areas under the epidermis. There was lymphocyte infiltration at the periphery of the cells. For gluteal mass, TVT cells were confined in muscle bundles. Transmissible venereal tumor cases are often located in genital organs and their metastases are rarely encountered in comparison with other tumors. In this case report, metastases to cervical tissue, neck skin, oropharyngeal mucosa and gluteal muscles, mammary lobes are found. Discussion: When the sexual activity is high, the incidence of TVT increases. It especially develops in bitches in estrus. Breed, sex and age are not a cause of predisposition for TVT. Transmissible venereal tumors’ malignancy can increase in some cases, although TVT is known as a benign tumor. Prevalence of metastases was found fairly low in the studies. Metastases to mammary region, to subcutaneous region, to brain, to eye, to lung, to uterus, to ovary, to liver, to spleen have been reported. In conclusion, even if a bitch is acyclic, transmissible venereal tumor can be developed and thus the risk of its disseminated metastasis must be considered. Moreover, since the masses have not regresed for a long time, this situation may be related to severe immunosupression in the bitch. © 2017 Universidade Federal do Rio Grande do Sul. All rights reserved.Öğe Determination of reproductive response to different synchronization methods and profitability during the transition to anoestrus in multiparous Kangal sheep(Veterinarni A Farmaceuticka Univerzita Brno, 2024) Takci, Abdurrahman; Kivrak, Mehmet Bugra; Murat, Hakan; Yuksel, MuratThe aim of the study was to determine a reproductively and economically successful synchronization method for Kangal sheep during the transition period from the breeding season to anoestrus. A total of 212 Kangal sheep were divided into three groups. On day 0, a sponge containing progesterone (P4) hormone was inserted intravaginally into the animals of Group 1 (n = 75). The sponges were removed 9 days later, and equine chorionic gonadotropin (eCG) and prostaglandin F2 alpha (PGF2 alpha) hormones were injected. Animals in Group 2 (n = 65) were given PGF2 alpha hormone at 9-day intervals. In addition to the second PGF2 alpha injection, eCG was also administered. A double dose of PGF2 alpha was administered to animals in Group 3 (n = 72) at 9-day intervals. The animals in this group were administered eCG along with the first PGF2 alpha injection. As a result of the applications, Group 1 showed a higher rate of oestrous than the other two groups (P < 0.05). There was no difference in pregnancy rates between Group 1 and the other groups. The pregnancy rate of Group 2 was significantly lower than that of Group 3. While there was no difference between the groups regarding multiple pregnancies, the fertility rate of Group 3 was higher than in the other two groups. Cost evaluations showed that the synchronization technique used in Group 3 was the most cost-effective. It was determined that the synchronization method used in Group 3 is preferred for Kangal sheep during the transition period.Öğe Determination of the causative agent of periparturient period interdigital dermatitis that adversely affects reproduction and milk production in cows by MALDI-TOF(Revista Pesquisa Veterinaria Brasileira, 2023) Takci, Abdurrahman; Mogulkoc, Mahmut Niyazi; Sancak, Tunahan; Kivrak, Mehmet BugraIn recent years, problems associated with high milk yield in dairy cows have increased considerably. Today, interdigital dermatitis (ID) is one of the most significant problems across the dairy industry, threatening animal health and welfare and inducing serious productivity losses. The etiology and mechanism of damage caused by this disease, which disrupts quality of life, milk yield, and reproduction, have not yet been fully understood. In order to achieve the study objectives, 40 biparous cows (3 years old - second calving) that had lameness associated with ID from prepartum day 30 to postpartum day 60 (Study group) and 40 biparous cows (3 years old) without lameness symptoms during the specified period (Control group) constituted the material of the present study. There was no difference in the levels of non-esterified fatty acids in the blood samples collected from those animals during the dry period (45-60 days before parturition; P=0.38). There were differences between the groups in certain parameters, including beta-hydroxybutyric acid level in the postpartum period, weight loss in the first month, number of ovarian cysts in the first 60 days, milk production in the first month, and the first corpus luteum determination process. (P<0.001) There was no difference between the groups in terms of reproductive parameters (mode of delivery, litter viability, litter weight, litter weight, expulsion of membranes, etc.) and presence of infection (acute puerperal metritis) during birth (P>0.05 for all parameters). In addition to all of the above, Wohlfahrtiimonas chitiniclastica bacteria were isolated for the first time in microbiological samples collected from ID, which is a significant condition for dairy cows during the periparturient stage, contributing to the etiology of the disease, which has not been understood so far.Öğe Determination of the efficacy of human Chorionic Gonadotropin (hCG) administrations on reproductive performance, placentation, parturition, and neonatal parameters on different post-mating days in Kangal ewes sexually induced during anestrus(Univ Zulia, Facultad Ciencias Veterinarias, 2023) Takci, Abdurrahman; Kivrak, Mehmet BugraThis study aimed to determine the efficacy of post mating human Chorionic Gonadotropin (hCG) during anestrus on the formation of the accessory corpus luteum and some reproductive parameters. For this purpose. after synchronization of all the animal were divided into group 1 (n=100), group 2 (n=100), and group 3 (n=100) by applying 600 IU of hCG 6 d after sponge removal, 600 IU of hCG 8 d after sponge removal, and no hCG application (Control), respectively. The difference between groups in terms of reproductive parameters such as estrus, pregnancy, multiple pregnancy, litter size, and productivity was not statistically significant. The live birth weight of lambs was evaluated for singletons, twins, and triplets. The difference between group 1 and the control group was statistically significant in singleton lambs (P=0.04). The difference between group 1 and control (P<0.001) and between group 2 and control (P<0.001) was statistically significant for twins. In triplets, group 1 was different from both groups (P<0.001) and group 2 was different from the control group (P<0.001). In addition, when the placenta weight and the daily body weight gain of singleton lamb in the neonatal stage were examined, the values of both groups that were administered with post mating hCG were higher than the control group (P<0.001). The Progesterone (P-4) level in blood samples taken on the 21(st) d of pregnancy was found to be different between all groups. Furthermore, P-4 levels were found to be higher in group 1 compared to the other two groups (P<0.001). In the light of these findings, it was determined that hCG administration after mating contributed to placenta and offspring development by elevating P-4 levels. It was concluded that hCG should be administered 6 d after the sponge will be removed (on d 5 postmating) for optimal efficacy.Öğe Effect of additional progesterone treatment during intravaginal progesterone priming in anestrous ewes(Polish Soc Veterinary Sciences Editorial Office, 2023) Takci, Abdurrahman; Kivrak, Mehmet BugraOestrus induction with intravaginal progesterone is the most preferred method in anoestrus sheep. In previous studies it was argued that the decrease in the progesterone level before the sponge is removed reduces the efficiency. This study aimed to test the hypothesis that additional progesterone treatment during the progesterone priming in anestrous ewes could increase the reproductive efficiency of the induction. The study conducted on 261 Kangal sheep, which were pregnant in autumn and gave birth in spring and breastfed their lambs for about 60-75 days. All animals included in the study were randomly divided into 3 different groups as P-7 (n = 86), P-8 (n = 80) and control (n = 95). At the beginning of the study a progesterone impregnated sponge was placed to all ewes (Day 0). During sponge treatment, an injection of progesterone was given to P-7 and P-8 group 7 and 8 days after the was sponge placed, respectively. As for control group, no additional progesterone was given during sponge treatment. All groups received 500 IU pregnant mare serum gonadotropin at the sponge withdrawal. Ram was introduced to all ewes the 10th days of the study. There was no difference between the groups in terms of estrus rate (P = 0.28), pregnancy rate (P = 0.32) and multiple pregnancy rates (P = 0.38) (P = 0.28). We considered that the main reason for unexpected low progesterone concentration at the end of the treatment might be the result of high feed intake and metabolic rate. On the other hand, this additional dose could be caused by an excessive increase in progesterone levels in the sheep, which could be the reason for the decrease in reproductive parameters. Additional progesterone support during progesterone -based synchronization yielded acceptable results. However, progesterone can be administered in injection form in the earlier days of synchronization or before sponge insertion to obtain better results.Öğe Evaluation of hormonal protocols for induction of synchronized estrus on reproductive indices in Kangal-Akkaraman ewes during the outbreeding season(Elsevier, 2022) Cizmeci, Sakine Ulkum; Kivrak, Mehmet Bugra; Takci, Abdurrahman; Dinc, Dursun Ali; Coskun, BehicThe objective of this study was to assess the effect of human chorionic gonadotropin (hCG) and gonadotropinreleasing hormone (GnRH) treatment before sponge insertion and anti-Mullerian hormone (AMH) concentration in ewes which were either pregnant or non-pregnant during the previous breeding season. In the study, 375 (3-6-year-old) Kangal-Akkaraman ewes that conceived or did not conceive in the preceding breeding season, and 36 rams (3-6-year-old) were used. The sheep were randomly divided into 5 equal groups. Blood samples were taken before stimulation (day 4), the day stimulation was initiated (day 0), after stimulation (day 9), on the mating day (days 11-12). AMH concentrations were measured in the samples taken on 4th day. As a conventional method, a sponge containing 20 mg of flugeston acetate (Chronogest (R) CR, MSD, Turkey) was placed intravaginally (day 0) into to study ewes. The ewes were intramuscularly administered 131.5 mu g prostaglandin F2 alpha (Estrumate, MSD, Turkey) and 600 IU equine chorionic gonadotropin (Chronogest (R) PMSG 6000, MSD, Turkey) simultaneously with sponge removal 9 days after insertion. No other treatment was applied to group 5 which served as control. Ewes in groups 1, 2, and 3 received an intramuscular injection of GnRH (4.2 mu g of Buserelin acetate, Receptal, MSD, Turkey) at the time of insertion of progesterone sponge. GnRH or 600 IU hCG (Chorulon (R), MSD, UK) was administered 4 days prior to sponge insertion for the ewes in the groups 2, and 3, respectively. As for the group 5 group, hCG (instead of GnRH) was administered to the ewes at the beginning of the progesterone treatment. Ewes in estrus were detected with a teaser ram and taken into a different pen with rams. Transrectal ultrasonography (Mindray DP50/Vet/US, rectal probe) was achieved during days the 30-35 following mating. Transabdominal ultrasonography was achieved during days 60-65 to detect late embryonic and early fetal death. The estrus rate was 71.19 % out of breeding season for all ewes. The pregnancy rate on day 30 post-mating was 32 % in the control group and was 31.00 %. No significant differences were observed between groups for pregnancy rates on day 30. The mean pregnancy rate in sheep that conceived and did not conceived in the preceding breeding season of the study was 32.03 % and 32.06 % respectively (P > 0.05). After treatments, AMH concentrations in non-pregnant were significantly higher than pregnant ewes (P < 0.005). In conclusion, although the AMH concentration is significantly higher in non-pregnant ewes, the AMH concentration may not be a suitable biomarker to predict induction success outside breeding season. Progesterone-based protocols may achieve an acceptable reproductive outcome in lactating ewes and the ones which experienced infertility.Öğe Induction of ovulation using repeated doses of sulpiride, a dopamine antagonist, in ewe lambs(John Wiley and Sons Inc, 2023) Kivrak, Mehmet Bugra; Aydin, IbrahimThis study aimed to test the hypothesis that sulpiride can increase the concentration of circulating gonadotropin that can promote puberty in pre-pubertal ewe lambs. Here, 12 1–3-year-old Merino rams and 60 7–9-month-old Merino sheep were included in the study. The sheep were randomly divided into sulpiride (n = 30) and control (n = 30) groups. The sulpiride group was subcutaneously injected with 0.6 mg/kg sulpiride twice daily (morning and evening) for 9 days. During these 9 days, blood samples were taken from the sheep before drug administration and at 4 h after every drug administration. The number of ovulating animals in the sulpiride group was significantly higher than that in the control group (90% vs. 32%). No oestrous signs were observed in either group during ram release. Further, there were no differences in the levels of mean follicle-stimulating hormone in the two groups based on treatment (p =.2), time (p =.3) or treatment-by-time interaction (p =.3). After sulpiride administration, the luteinizing hormone (LH) levels of the sulpiride group rapidly increased and remained stable for a long time, whereas physiological LH fluctuations in the control group remained unchanged. Within-group changes in terms of LH concentrations were significant for both groups (p <.001), whereas LH pulse frequency was significantly different between the sulpiride group (p =.03). Therefore, it is concluded that sulpiride can be used as a non-steroidal alternative to stimulate pre-pubertal ewe lambs and sheep during anoestrus. © 2022 Wiley-VCH GmbH.Öğe Interaction of cumulus-oocyte complex (coc) number, oocyte quality, and blastocyst numbers by repeated ovum pick-up (opu) in in vitro embryo production(Chulalongkorn University Printing House, 2024) Cizmeci, Sakine Ulkum; Dinc, Dursun Ali; Bucak, Mustafa Numan; Yesi̇Lkaya, Omer Faruk; Ciftci, Muhammed Furkan; Kivrak, Mehmet Bugra; Sari, AyseOvum pick-up (OPU) is a repeatable technique that is used for the retrieval of large numbers of immature oocytes from the antral follicles of live animals. The aim of the present study was to determine the effect of repeated OPU application on cumulus-oocyte complex (COC) number, oocyte quality, and blastocyst rates. The animal material for the study consisted of 10 Holstein heifers. Heifers selected as donors were administered OPU a total of 9 times on random days of the cycle at 1-week intervals. All antral follicles with a diameter of 2-8 mm were aspirated during the OPU procedure. In vitro embryo production (IVEP) was performed on the oocytes obtained after quality assessment. Various degrees of adhesion and connective tissue thickening were found in the ovaries of the animals after 9 repeated applications of OPU. It was found that the average number of A-quality oocytes was higher than the number of B, C, and D-quality oocytes. The number of cleavages per OPU was 2.69 (cleaved oocytes/opu session), and the number of blastocysts was 0.72 (number of blastocysts/opu session). It was determined that the general average of cleavage ratios was 73.62%, and blastocyst rates were 18.97%. It was observed that the number of oocytes, cleavage, and blastocysts obtained as a result of repeated OPU applications was not affected by repeated OPU. It was concluded that in order to achieve the target number of oocytes and blastocysts with recurrent OPU, experiments should be carried out with varying frequencies of OPU, and prophylactic measures should be taken to prevent adhesions. © 2024 Chulalongkorn University Printing House. All rights reserved.Öğe Pharmacokinetics of letrozole and effects of its increasing doses on gonadotropins in ewes during the breeding season(Wiley, 2024) Kivrak, Mehmet Bugra; Corum, Orhan; Yuksel, Murat; Turk, Erdinc; Corum, Duygu Durna; Tekeli, Ibrahim Ozan; Uney, KamilLetrozole is a non-steroidal, third-generation aromatase inhibitor used in humans. Although letrozole is not approved for use in animals, it is used off-label in cases of synchronization and infertility. The aim of this study was to determine the pharmacokinetics of letrozole after a single intravenous administration at three different doses in ewes during the breeding season and its effect on gonadotropins (luteinizing hormone (LH) and follicle-stimulating hormone (FSH)) at the beginning of proestrus. The study was carried out on 24 healthy Merino ewes. Ewes were randomly divided into four groups (n = 6) as control, 0.5, 1, and 2 mg/kg. Plasma concentrations of letrozole were measured using HPLC-UV and were analyzed by non-compartmental analysis. LH and FSH concentrations were measured with a commercial ELISA kit. The terminal elimination half-life (t(1/2 lambda z)) was significantly prolonged from 11.82 to 18.44 h in parallel with the dose increase. The dose-normalized area under the concentration-time curve (AUC) increased, and total body clearance (Cl-T) decreased at the 1 and 2 mg/kg doses (0.05 L/h/kg) compared with the 0.5 mg/kg dose (0.08 L/h/kg). There were no differences in the volume of distribution at steady-state and initial (C-0.083h) plasma concentration values between dose groups. The decreased ClT, prolonged t(1/2 lambda z), and increased AUC at increasing doses showed the nonlinear kinetic behavior of letrozole. Letrozole significantly reduced LH concentration without affecting FSH concentration at all doses. As a result, letrozole has the potential to be used in synchronization methods and manipulation of the follicular waves due to its effect on LH secretion.Öğe Pulse wave Doppler ultrasound of umbilical cord in experimentally induced pregnancy toxemia in sheep(Elsevier Sci Ltd, 2023) Kivrak, Mehmet Bugra; Turk, Sefer; Takci, Abdurrahman; Bolukbas, Bora; Agaoglu, Recep Taha; Coskun, AlparslanContrary to its widespread use in human cases, the use of Doppler ultrasonography is only recently becoming prevalent in farm animals. This study aimed to determine the effects of maternal metabolic and clinical changes on fetal hemodynamics during pregnancy toxemia with the doppler examination of umbilical cord. In the study twenty ewes with a single healthy fetus were included in the study. At the end of the 120th day of pregnancy, 20 single-bearing pregnant ewes were randomly categorized into two groups. Ewes in the control group were fed to meet all nutritional requirements. On the other contrary, the experimental ewes were fed to meet equivalent to 50 % of the daily needs and then fasted for 96 h. Doppler ultrasonographic examinations of umbilical cord were performed once every two days and once a day during fasting. Beta hydroxybutyric acid (BHBA) concentration was measured by taking blood from sheep on examination days. Pulse systolic velocity (PSV), end diastolic velocity (EDV), PSV/EDV, pulsatility index (PI), resistance index (RI), and fetal heart rate (FHR) as well as BHBA values and how those parameters has changed over time (time by treatment effect) due to energy deprivation during pregnancy were evaluated using repeated measure analysis of variance. No clinical signs were observed in both toxemia and control groups during restricted feeding. BHBA concentration increased and there was a significant time, time by treatment and main effect of treatment effect between groups. No significant main effect of treatment and time by treatment interaction was observed in the changes of PI, RI, FHR, and systolic/diastolic velocity values over time in both groups. FHR was reduced over time, and there was a significant time effect in FHR in both groups. Although doppler indices didn't increase, both PSV and EDV values increased significantly in the pregnancy toxemia group compared with the controls (Time P = 0.03, time by treatment interaction P < 0.05) and the main effect of treatment P < 0.05). The marked increase in blood velocities (PSV and EDV) in the umbilical cord is probably due to the compensatory functioning for excessive energy deprivation of the fetus. Therefore, PSV and EDV might be a valuable indicator for evaluating the fetus's health status during the management of the PT.Öğe The Effect of Size and Clinical Staging of Mammary Tumors on Blood Parameters in Bitches(Univ Fed Rio Grande Do Sul, 2022) Satilmis, Fatma; Alan, Beyza Suvarikli; Altunok, Vandettin; Kivrak, Mehmet Bugra; Demirsoz, Mert; Alkan, Hasan; Aydin, IbrahimBackground: Mammary tumors arc the most common type of tumor in female dogs and account for 50% of all tumors in dogs. The clinical prognosis of canine mammary tumors is strongly affected by the size, stages, histological type, and grade of tumor; mitotic index; and nearby and distant metastasis. In canine manunary tumors, it is recommended that prognostic evaluation should also include complete blood count, serum biochemistry, and blood gases in addition to tumor size and stage. This study aimed to investigate the effect of tumor size, volume, and clinical stage on complete blood count, blood gas analysis, and serum biochemical parameters in bitches with mammary tumors and the correlation between them. Materials, Methods & Results: The study included a total of 18 bitches of different breeds, aged 6-15 years, of which 12 had mammary tumors and 6 were healthy. Thoracic X-rays were performed on bitches with mammary tumors in ventrodorsal and laterolateral positions to evaluate lung metastasis. Blood samples were collected from the cephalic vein from hitches in both groups in 2 different tubes (with plastic gel and ethylenediaminetetraacetic acid), 5 mL each, to perform complete blood count and evaluate blood gases and serum biochemical parameters. Blood samples were collected from the animals at the time of initial examination without any intervention. Analysis of the blood showed that bitches with mammary tumors had decreased levels of RBC, HCT, HGB, potassium, TCO2, base excess, THbc, and ALT enzyme activity and increased levels of lactate, total protein, cholesterol, triglyceride, LDL, uric acid, and ALP and LDH enzyme activities compared with those in the control group. Furthermore, the dogs with a primary tumor of > 5 cm were found to have significantly higher levels of WBC, lactate, total protein, triglyceride, LDL, uric acid, and ALP and LDH enzyme activities and significantly lower levels of RBC and THbc compared with those in the control group. Bitches with tumors in multiple mammary lobes were found to have significantly higher levels of WBC, total protein, triglyceride, and ALP and LDH enzyme activi- ties and significantly lower levels of RBC, I ICT, HGB, TCO2, Tithe, and ALT enzyme activity compared with those in the control group. Based on the laboratory findings and approval of the owners of the dogs, mammary tissues containing the tumor and lymph nodes were surgically removed. After the operation, the removed mammary tissues were evaluated for size and volume. Clinical staging of the tumors was performed based on the size of the primary tumor (T), nearby lymph nodes (N), and metastasis (M) in accordance with the criteria set by WHO. Clinical staging of the tumors was, thus, based on the tumor, nodes, and metastases (TNM) score obtained according to the following system: Stage I: T1N0M0, Stage II: T2N0M0, Stage III: T3N0M0, Stage IV: TanyN1M0, Stage V: made as TanyNanyM1. Discussion: Mammary tumors are the most common type of neoplasm in bitches and, thus, cause serious problems in veterinary medicine. Tumors arc significantly correlated with better prognosis compared with larger tumors. Based on this finding, this study investigated the effect of size, volume, and stage of mammary tumors in bitches on some blood parameters and the correlation between them. Therefore, it was concluded that clinical staging and evaluation of blood parameters could be useful in the diagnosis, treatment, and prediction of prognosis in canine mammary tumors. This study found that bitches with mammary tumors exhibited significant changes in their blood parameters (complete blood count, blood gas analysis, and serum biochemistry). The results obtained from this study may contribute to the development of approaches to the diagnosis, prediction of prognosis, and treatment of canine mammary tumors.Öğe The pharmacokinetics of letrozole and its effect on gonadotropins in anestrous ewes(Elsevier Science Inc, 2021) Kivrak, Mehmet Bugra; Corum, Orhan; Alkan, Hasan; Atik, Orkun; Aydin, Ibrahim; Uney, KamilThe aim of this study was to determine the pharmacokinetics of letrozole and its effect on FSH and LH concentrations after single (IV, IM, SC) and repeated IV doses in anestrous ewes. This study was conducted in experiments 1 and 2 by randomly dividing 24 healthy Akkaraman ewes in anestrus into two equal groups. In experiment 1, the pharmacokinetics of letrozole following single IV, IM, and SC administration at 1 mg/kg dose and its effect of a single IV dose on plasma FSH and LH concentration were determined. In experiment 2, the effect of repeated IV doses of letrozole on FSH and LH concentrations was established. Plasma concentration of letrozole was measured using high-performance liquid chromatography, and pharmacokinetic parameters were calculated by non-compartmental analysis. FSH and LH concentrations were quantified using ELISA. The elimination half-life (t(1/2 lambda z)) for IV, IM, and SC routes were 9.94, 37.29, and 41.07 h, respectively. The IV route for letrozole had a total clearance of 0.11 L/h/kg and a volume of distribution at a steady state of 1.50 L/kg. The peak plasma concentration was 0.11 mu g/mL for the IM route and 0.14 mu g/mL for the SC routes. The bioavailability was 55.18% for the IM route and 75.34% for the SC route. Letrozole following single and repeated (every 24 h for 3 days) IV administrations at 1 mg/kg dose did not affect LH concentration in anestrous ewes but caused an increase in the FSH concentration. This increase in FSH concentration may create a potential for the use of letrozole in ovarian superstimulation protocols. Favorable pharmacokinetic properties (long t(1/2 lambda z) and good bioavailability) of letrozole for IM and SC routes require further investigation before use in estrus induction or estrus synchronization protocols in sheep. (C) 2021 Published by Elsevier Inc.Öğe The pharmacokinetics of sulpiride and its effect on sexual behaviours and LH concentrations in anestrous does (Capra hircus)(Elsevier, 2025) Yuksel, Murat; Corum, Orhan; Kivrak, Mehmet Bugra; Corum, Duygu Durna; Turk, Erdinc; Takci, Abdurrahman; Yardimci, Sara BusraThe aim of this study was to investigate the pharmacokinetics of sulpiride and its effect on sexual behaviours and LH concentrations in anestrous does (Capra hircus). This study was carried out in two stages: pharmacokinetics (stage I) and effect on LH pulsatility, concentration, and estrus display (stage II). In the stage I, sulpiride was administered via intravenous (IV), intramuscular (IM), subcutaneous (SC) and oral routes to does at a dose of 0.6 mg/kg. In the stage II, sulpiride was administered intramuscularly at a dose of 0.6 mg/kg every 12 hours for 10 days. Plasma concentrations of sulpiride were measured using HPLC and pharmacokinetic parameters were calculated by non-compartmental analysis. LH concentrations were quantified using ELISA. The terminal elimination half-life, apparent volume of distribution, and total body clearance of sulpiride following IV administration were 1.76 h, 0.38 L/kg, and 0.15 L/h/kg, respectively. The peak plasma concentration of IM and SC administration was 1.39 and 0.83 mu g/mL at 0.53 and 0.78 h, respectively. The bioavailability of sulpiride was 103.30 % for the IM route and 72.21 % for the SC route. Sulpiride showed erratic and low absorption after oral administration. While LH concentrations decreased significantly after sulpiride administration, the LH plus frequency increased significantly. In conclusion, sulpiride with distinctive effect on LH pulse frequency has the potential to be used in protocols for hastening cyclicity. However, more studies are needed on the use of sulpiride in estrus induction protocols.
