小尾寒羊不同乳腺发育时期7种激素分泌规律

Secretion rule of seven hormones of Small-Tailed Han sheep during different mammary gland development periods

【目的】激素调控了奶牛和奶山羊的乳腺生长发育和泌乳,但目前在绵羊中的研究还不够全面和系统。【方法】以小尾寒羊为研究对象,在空怀期、妊娠早期、妊娠中期、妊娠末期、泌乳早期和泌乳中后期6个乳腺发育时期,采用酶联免疫吸附法测定血液中雌激素、孕酮、催乳素、生长激素、糖皮质激素,胰岛素和胰岛素样生长因子I的浓度,分析激素对绵羊乳腺发育的调控作用。【结果】雌激素和孕酮浓度呈先上升后下降的总体趋势,它们在妊娠末期的浓度最高(分别为73.01 pg/mL和530.48 pmol/L),在空怀期的浓度最低(分别为35.69 pg/mL和485.46 pmol/L);从空怀期开始,催乳素浓度持续升高,在泌乳早期达到最大值,其在泌乳早期的浓度分别比妊娠中期、泌乳中后期、妊娠早期和空怀期高12.47%、16.17%、46.15%和59.66%(P<0.05);妊娠末期的糖皮质激素浓度最大(495.28 pg/mL),较妊娠早期和空怀期分别高14.36%和12.42%(P<0.05);胰岛素含量由大到小依次为妊娠早期(36.22 mIU/L)>妊娠末期(36.10 mIU/L)>泌乳早期(35.98 mIU/L)>妊娠中期(35.49 mIU/L)>空怀期(33.78 mIU/L)>泌乳中后期(32.22 mIU/L),空怀期、泌乳中后期与其它时期的胰岛素含量差异显著(P<0.05)。然而,生长激素和胰岛素样生长因子I的浓度在6个时期之间无显著差异(P>0.05)。【结论】在绵羊6个乳腺发育时期,雌激素、孕酮、催乳素、糖皮质激素和胰岛素这5种激素的浓度有显著差异(P<0.05),说明它们可能影响了绵羊乳腺的生长发育和泌乳功能。

【Objective】Hormones regulate the growth and development of the mammary gland and lactation in dairy cows and goats.However,there have been no comprehensive and systematic studies of hormone secretion in sheep.【Method】Six mammary gland periods of Small-Tailed Han sheep were selected to determine the levels of progesterone,estrogen,prolactin,growth hormone,glucocorticoid,insulin,and insulin-like growth factor I in blood using an enzyme linked immunosorbent assay,including nonpregnancy,early pregnancy,mid-pregnancy,late pregnancy,early lactation and mid-late lactation periods.【Result】The concentrations of estrogen and progesterone showed a general trend of increasing first and then decreasing.The concentrations of estrogen and progesterone were the highest at late pregnancy with a concentration of 73.01 pg/mL and 530.48 pmol/L,respectively,while their concentrations were the lowest in non-pregnancy with a concentration of 35.69 pg/mL and 485.46 pmol/L,respectively.The concentration of prolactin increased continuously from non-pregnancy with the highest value at early lactation periods,and its content in early lactation was 12.47%,16.17%,46.15%and 59.66%higher than that in mid-pregnancy,mid-late lactation,early pregnancy and non-pregnancy,respectively(P<0.05).The glucocorticoid level was the highest in late pregnancy(495.28 pg/mL),and its level in the late pregnancy was 14.36%and 12.42%higher than that in early pregnancy and non-pregnancy,respectively(P<0.05).The insulin level was the highest in early pregnancy(36.22 mIU/L),followed by late pregnancy(36.10 mIU/L),early lactation(35.98 mIU/L),mid-pregnancy(35.49 mIU/L),non-pregnancy(33.78 mIU/L),and mid-late lactation(32.22 mIU/L).Insulin levels were significantly different between the non-pregnancy,mid-late lactation and other periods(P<0.05).However,there were no significant differences in the level of growth hormone and insulin-like growth factor I between the six periods(P>0.05).【Conclusion】The concentrations of estrogen,progesterone,prolactin,glucocorticoid and insulin were significantly different at six different stages of mammary gland development in Small-Tailed Han sheep(P<0.05),suggesting that they may affect mammary gland growth and development and lactation in sheep.