Development change of growth hormone, insulin and their receptors in mammary gland of dairy goats | 奶山羊乳腺发育过程中生长激素、胰岛素及其受体的变化规律研究

Chinese. 【目的】探讨奶山羊乳腺发育过程中生长激素、胰岛素及其受体表达规律。【方法】关中奶山羊乳腺发育的4个时期即青春期、妊娠期、泌乳期及退化期用放射性免疫学方法（RIA）测定激素的含量,用免疫荧光法（IF）检测激素受体含量。【结果】在乳腺发育过程中血清中生长激素（GH）变化不显著（P＞0.05）,而组织中的GH在妊娠5月（P5M）时出现分泌高峰2.599±0.459 ng mL-1（P＜0.01）。血清中胰岛素（INS）在青春期含量变化差异不显著（P＞0.05）,到妊娠1月（P1M）时INS含量高达31.664±6.416 micro IU mL-1（P＜0.01）,泌乳高峰过后回到正常水平。组织中的INS在进入妊娠期后含量开始增加并持续到泌乳10日（L10D）,之后下降。生长激素受体（GHR）在妊娠期比青春期和泌乳早中期高,在泌乳晚期达到高峰,之后下降。胰岛素受体（INSR）从青春期开始缓慢上升,在泌乳启动后达到高峰。【结论】在乳腺发育过程中血清和乳腺中的GH变化不明显。血清中的INS水平在妊娠初期最高,至分娩时最低,而乳腺中INS在泌乳期处于高水平。GHR在妊娠期和泌乳后期、退化前期表达量较高。INSR在妊娠期和泌乳期维持在一个较高水平,至泌乳中后期下降。

English. 【Objective】 The aim of the experiment was to investigate the change of growth hormone (GH) and insulin (INS) in development of dairy goat mammary gland, and the expression of growth hormone receptor (GHR) and insulin receptor (INSR) in the same periods. 【Method】The mammary glands of Chinese Guanzhong dairy goats based on the development character were divided into 4 periods, virgin, pregnancy, lactation and involution. The levels of GH and INS in serum were measured by radioimmunoassay (RIA), and the expressions of GHR and INSR in tissue were measured by immunofluorescence (IF).【Result】 No remarkable difference in GH changes (P＞0.05) in serum was observed, but in mammary gland the level of GH reached the peak in late pregnancy (2.599±0.459 ng mL-1, P＜0.01). The level of INS in serum had no significant difference in virgin (P＞0.05) and in early pregnancy it reached 31.664±6.416 micro IU mL-1 (P＜0.01). In mammary gland INS began to increase after pregnancy and maintained to lactation. The expression of GHR in pregnancy was higher than in virgin and in early metaphase of lactation, and reached maximum at the late of lactation. INSR increased slowly from virgin and reached the top after the lactogenesis. 【Conclusion】 In the development of mammary gland, GH not changed obviously in serum and mammary gland. The content of serum INS gradually reduced during the pregnancy period. While in mammary gland it got down gradually in the lactogenesis. GHR expressed higher in pregnancy, the later lactation and the early involution periods. The expression of INSR maintained at a high level during the pregnant and lactation periods.