Turkish Journal of Veterinary and Animal Sciences

Yazarlar: Güler ÜNAL, Hatice KARAKİŞİ, Mahmut ELP

Konular:-

Anahtar Kelimeler:Chalcalburnus tarichi,Postovulatory follicle,Ovarian steroids

Özet: The structure of postovulatory follicles and the levels of ovarian 11-dehydrocorticosterone (11-DHC), estradiol-17b (E2), 17a-hydroxyprogesterone (17a -OH-P), and progesterone (P), before and after spawning, were studied in Chalcalburnus tarichi. It was observed that postovulatory follicles are characterized by a highly vascular thecal layer and hypertrophied granulosa cells containing dense smooth endoplasmic reticulum, many large mitochondria with tubular cristae, and lipid droplets. Ovary 11-DHC level was low in the pre- and post-spawning periods (38.3 ± 4.9-22.3 ± 2.6 ng/ml). The level of E2 was 216.8 ± 31.1 ng/ml before spawning. This hormone declined on the 1st and 5th day after spawning and increased again to the level of 216.8 ± 6.7 ng/ml on the 10th day; however, the E2 level decreased significantly on the 15th day (61.5 ± 17.8 ng/ml) (P < 0.01). The 17a -OH-P level was low (84.5 ± 49.4 ng/ml) before spawning and reached a peak (295.7 ± 52.5 ng/ml) on the 10th postspawning day, but a slight decline was observed on the 15th day (190 ± 21.5 ng/ml) (P > 0.01). The P level was low (23.4 ± 18.3 ng/ml) before spawning. Its level began to increase after spawning and reached a peak on the 10th postspawning day (200.7 ± 29.1 ng/ml) (P < 0.01), but declined significantly on the 15th day (63.2 ± 19.5 ng/ml) (P < 0.01). The results obtained from this study indicate that: a) In the postovulatory follicles, the granulosa cells produce steroids; b) 11-DHC has no effect before or after spawning; c) E2 induces spawning; d) 17a -OH-P and P have an effect after spawning. It can be concluded that the apoptotic cells in postovulatory follicles increased on the 15th day, at which time E2 and P hormones were at their lowest levels after spawning in C. tarichi.

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