Gonadotrophin concentrations in sheep plasma after injections of GnRH without a mixture of serine and threonine

Bu çalışma; Serin ve Threonin amino asitlerinin, GnRH ile birlikte veya ayrı olarak, doğal kızgınlık döngüsü seyrinde olan koyunlara enjekte edilmesi sonucu kan plazmasında meydana gelen LH ve FSH konsantrasyonlarında değişmeleri ölçmek ve analiz etmek için yapıldı. Birinci deneyde, jugular damardan koyunlara saat 11:00 ve 14:00 da olmak üzere iki kez enjeksiyon yapıldı. İki seferdede tuz çözeltisi enjekte edilen koyunlar (Salina/Salina (S/S)) kontrol olarak tutuldu. Test gurupları: Salina/GnRH (S/GnRH), Salina/Amino asit karışımı ve GnRH (S/AA+GnRH), Amino asit karışımı ve GnRH (AA/GnRH), Amino asit karışımı ve amino asit karışımı ile birlikte GnRH (AA/AA+GnRH). Birinci deneyde, ilk enjeksiyondan 60 dakika önce olmak üzere koyunlardan 15, 30, 60 dakika aralıklarla ilk enjeksiyondan 360 dakika sonrasına kadar kan alındı. İkinci deneyde, saat 10:00 dan başlamak üzere her iki saatte bir 7 koyuna salina enjeksiyonu, diğer 8 tanesine ise amino asit enjeksiyonu yapıldı. İlk deneyde; birinci enjeksiyonu müteakip, 180-300 dakikalar arası kontrol gurubu (S/S) hariç olmak üzere tüm guruplarda, plazma LH konsantrasyonu arttı (P < 0,05). Amino asitlerin GnRH enjeksiyonundan üç saat önce enjekte edilmesi ve üç saat önce enjekte edilip sonradan tekrar GnRH ile birlikte enjekte edilmesi sonucu AA/GnRH ve AA/AA+GnRH gurubunda 180-300 dakikar arası plazma LH konsantrasyonunda daha büyük bir artış sağlandı (P < 0,05). İkince deneyde, amino asit karışımının iki saat aralıklarla enjeksiyonu LH konsantrasyonunda bir değişikliğe sebep olmaz iken FSH konsantrasyonunu azalttı (P < 0,05). Bu azalmanın nedeni, ovaryumlardan salgılanan inhibin ve benzeri faktörlerin hipofiz üzerine negatif geri etkisinin bir sonucu olabilir.

Serin ve threonin amino asitlerinin GnRH ile birlikte veya ayrı olarak enjeksiyonunun koyunun kan plasmasındaki LH ve FSH konsantrasyonuna etkisi

This study was designed to test the effect of Serine and Threonine mixture with or without a GnRH dose on plasma LH and FSH concentrations in naturally cycling ewes. Two experiments were conducted. In the first experiment, the ewes were _ intravenously injected by jugular vein twice at 11.00 am and 2.00 pm as Saline/Saline (S/S, control), Saline/GnRH (S/GnRH), ' Saline/Amino acids and GnRH (S/AA+GnRH); Amino acids/GnRH (AA/GnRH), Amino acids'/Ammo acids with GnRH (AA/AA+GnRH). Blood samples were collected at 15, 30 and 60 min intervals from 60 min before, until 360 min following the first injection. In the second experiment, control and treatment groups received five saline or aminoacids mixture at two hours intervals beginning at 10.00 am. Injection of GnRH significantly increased plasma LH concentrations in all groups between 180 and 300 min following the first injections (P < 0.05). When amino acid mixture were injected three hours before the GnRH injection or three hours before and then together with GnRH there were further significant increases in plasma LH concentrations in AA/GnRH and in AA/AA+GnRH groups between 180 and 300 min following the first injections. In the second experiment, injection of amino acid mixture at two hour intervals did not cause any.significant changes in plasma LH concentration (P > 0.05), while plasma FSH concentrations were suppressed (P < 0.05). The suppression of FSH concentration might be the result of an increased negative feedback of ovarian derived factors (most likely inhibin) on FSH secretion.

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