No abstract

No abstract

Leptin is mainly synthesised in white adipose tissue. Besides its effects on body weight and metabolic homeostasis, leptin also has effects on puberty, sexual maturation and reproduction. In this study the relationship between leptin, IGF-1, oestradiol (E 2 ) and progesterone levels were investigated in serum and follicular fluid from cows. This study included 72 healthy, Brown Swiss cows aged 4-5 years. Samples from the jugular vein and follicular fluids were collected. Phases of the oestrus cycle of cows were classified according to their serum progesterone levels (< 3.18 nmol/l, follicular phase and the others as luteal phase). Follicles were grouped as large (≥ 8 mm) or small (< 8 mm). Leptin, IGF-1, oestradiol and progesterone levels were measured from serum and follicular fluid. Leptin concentrations were found to be significantly higher in luteal-phase follicular fluid of small follicles (P < 0.05). These were classified as atretic follicles. There was a positive correlation between serum and follicular fluid leptin levels in the luteal phase. Serum leptin was found to have a positive correlation with follicular fluid progesterone level (P = 0.01) in the preovulatory follicles. The present study shows that there is a relationship between the concentration of leptin in follicular fluid and atresia in small follicles.

The aim of the present study was to investigate histochemically the localization of thyroid-stimulating hormone (TSH) cells and the number of TSH cells in adenohypophysis of ovariectomized adult females, intact females at estrous and diestrous phase of sexual cycles and castrated and non-castrated adult male rats. TSH cells, distributed throughout the pars distalis in all groups, were observed more frequent in areas near to the pars intermedia than other regions. The cells were round, ovoid, stellar-shaped and had contacts with sinusoids. Their nuclei were large and round-shaped. The cells were found mostly single or occasionally in groups of double and triple. The number of TSH cells was higher in estrous than diestrous phase in intact rats. In adenohypophysis of ovariectomized rats, their numbers were less than that of intacts in estrous, but higher than that of found in diestrous phases. Furthermore, the numbers of TSH cells in intact females during estrous phase was higher than those found in intact and castrated male rats. On the other hand, castration reduced the number of TSH cells while ovariectomy had no effect in this respect.

The effect of subclinical mastitis on serum estradiol and tumor necrosis factor alpha (TNF-α) levels during oestrus and subsequent fertility was investigated in dairy cows. 40 cows were divided into two groups as healthy control (n=20) and subclinical mastitis (n=20), according to the results of California Mastitis Test (CMT) and bacteriological isolation and identification. Cows were synchronised with a standart 7 day Ovsynch protocol. Following prostaglandin F2alpha (PGF2α) administration, cows were examined with trans-rectal ultrasonography at 24, 36 and 48 th h, dominant follicle diameters were recorded and blood samples were collected. Sixteen h after the second gonadotrophin-releasing hormone (GnRH) administration, cows were inseminated and a final examination of ovaries were performed and dominant follicle diameters were recorded. estradiol and TNF-α concentrations were analysed with ELISA in serum samples. No significant differences were found between the follicular diameters and growth patterns (P>0.05) of the two groups while estradiol concentations were significantly higher in the subclinical mastitis group than the control group at 24 and 48 h after PGF2α injection (P=0.017 and P=0.036 respectively). Also TNF-α levels were significantly higher in cows with subclinical mastitis than the control group (P=0.03). Positive correlations were observed between estradiol and TNF-α levels, in both groups (Control Group: R=0.512, P=0.021; Subclinical Mastitis Group: R=0.826, P<0.001). Overall pregnancy rate was higher in the control group (40%) than the subclinical mastitis (25%) group however the difference was not statistically significant (P>0.05). In conclusion estradiol and TNF-α concentrations were found higher in cows with subclinical mastitis during estrus and this data may be due to a luteal insufficiency during the initiation of synchronization, however further studies are required. Özet Süt ineklerinde subklinik mastitislerin serum östradiol ve tümör nekrozis faktör alfa (TNF-α) düzeyleri ve fertilite üzerine etkileri araştırıldı. Kaliforniya Mastitis Test (CMT) ve bakteriyolojik izolasyon identifikasyon sonuçlarına göre 40 inek sağlıklı kontrol (n=20) ve subklinik mastitisli (n=20) olmak üzere iki gruba ayrıldı. İnekler standart bir 7 günlük Ovsynch protokolü ile senkronize edildi. Prostaglandin F2 alfa (PGF2α) uygulamasını takiben inekler 24, 36 ve 48. saatlerde transrektal ultrasonografi ile muayene edildi, dominant follikül çapları kaydedildi ve kan örnekleri toplandı. İkinci gonadotropin salgılatıcı hormon (GnRH) uygulamasını takiben 16. saatte inekler tohumlandı, son bir ovaryum muayenesi yapıldı ve dominant follikül çapları kaydedildi. Serum örneklerinde östradiol ve TNF-α düzeyleri ELISA ile belirlendi. Folikül çapları ve folliküler gelişim özelliği yönünden iki grup arasında önemli bir fark görülmezken (P>0.05), serum östradiol konsantrasyonları subklinik mastitis grubunda kontrol grubuna göre PGF2α enjeksiyonunu takiben 24 ve 48. saatlerde belirgin ölçüde yüksek bulundu (sırasıyla, P=0.017 ...