半胱胺对湖羊生长激素分泌特点的影响

Effects of cysteamine on growth hormone secretion characteristics in adult Huyang sheep

对４只装有颈静脉导管的成年湖羊（自身对照）按６０ｍｇ／ｋｇ·ＢＷ的量一 次口服经保护的半胱胺，分别于对照期和处理后的第１、３、５、７天，间隔１５ｍｉｎ， 连续采３ｈｒ的血样，用放射免疫分析法研究了湖羊正常的生长激素分泌特点以及半 胱胺对其特点的影响。结果显示，成年湖羊的生长激素呈脉冲式分泌，其总体水 平、基线水平、 ３ｈｒ峰频率、峰持续时间和峰强度分别为 ３．８１± ０．４２ｎｇ／ｍｌ、 ２．４８ ± ０．２５ｎｇ／ｍｌ、 ３．００±０． ７４个、３２． １９±２．１８ｍｉｎ和 ３．０７±０．８８ｎｇ／ｍｌ。添喂半胱胺 后，生长激素的总体水平在第 ５天较对照期高 １２．３４％（Ｐ＜０．０５），基线水平在第 ３天、第５天和第７天分别较对照期高１７．７４％（Ｐ＜０．０５）、１４．１１％（Ｐ＜０．０５） 和１６．９４％（Ｐ＜０．０５），峰频率、峰持续时间和峰强度变化不显著（Ｐ＞０．０５）。以 上结果表明，保护性半胱胺经口服后，虽经瘤胃微生物的作用，仍可影响湖羊的神 经内分泌功能，提高生长激素的总体和基线水平，促进机体生长和代谢的改变。

Four adult Huyang sheep (about 40kg, two male and two female) were housed individually in this study Dry herbage and water were given and libitum and com-soybean diet was added two times each day (8: 00 and 17: 00) .The chronic catheters were placed into the jugular vein of animal under aseptic surgery.One week later, the blood samples were collected though the catheter at 15min intervals, starting at 13: 00pm, for 3 - hr. period as control.One day later, the sheep were fed the diet that added cysteamine at dosage of 60mg/kg BW.On day 1, day 3, day 5 and day 7 the blood samples were obtained in the same way as before for treatment. The plasma GH concentrations were measured by radioimmunoassay. The results showed that Huyang sheep growth hormone (GH) was pulsatile.Overall mean levels, base line levels, peak frequency, peak duration and peak amplitude of GH secretion were 3 .81 ?0 .42ng/ml, 2 .48 ?. 25ng/ml, 3 .00 ?0 .74peak/3hr, 32. 19 ?.18min and 3.07 ?0 .88ng/ml, respectively.After feeding CS, compared with the control periods, the overall mean level on day 5 was increased by 12.34% (4.28 ?0.47ng/ml vs.3.81 ?.42ng/ml, P<0.05), baseline contents on day 3, day 5 and day 7 were elevated by 17.74% (2.92 ?0.92ng/ml vs.2.48 ?0.25ng/ml, P< 0.05), 14.11% (2.83 ?0.27ng/ml, vs.2 .48 ?.25ng/ml, P< 0.05) and 16.94% (2.90 ?0.44ng/ml vs.2.48 ?0.25ng/ml, P< 0.05 ), respectively.Peak amplitude was lower than that of control period on day 3 and day 5 (2.63 ?0.24ng/ml and 2.09 ? 0 .70ng/ml vs. 3 .07 ?0. 88 ng/ml, P>0 .05). Peak frequency and peak duration had no significant different. The results indicate that CS taken orally can affect the GH secretory episodes in sheep. So that it can promote the growth and change the metabolism in sheep.