Strbák V, Jurcovicová J, Vigas M
Neuroendocrinology. 1985 May;40(5):377-80. doi: 10.1159/000124101.
To study the maturation of inhibitory influences on growth hormone (GH) secretion the effect of ether stress on plasma GH levels was studied during postnatal ontogenesis in female rats. Ether stress did not affect plasma GH levels in 1-day-old pups. A distinct decrease of plasma GH was found in 3- and 9-day-old pups, and the response was prevented by treatment of 3-day-old animals with somatostatin antiserum. No effect of ether stress on plasma GH was noted in 12-, 15-, 18- and 21-day-old rats. Treatment of intact 12-day-old pups with the somatostatin antiserum increased plasma GH level under basal conditions. The inhibitory effect of ether stress on plasma GH was noted again at the age 30 days and in adult animals. It is concluded that the hypothalamus of 3-day-old rats is able to release enough somatostatin to inhibit GH secretion after stress. At the period 12-18 days a phase of pituitary refractoriness was noted: ether stress as well as TRH injection (our previous observation) fail to affect plasma GH in female pups, probably due to high somatostatin secretion under basal conditions and (or) low capacity of pituitary to release GH. It is suggested that regulation of GH secretion is not mature until after the 21st day of life.
为研究对生长激素（GH）分泌的抑制性影响的成熟过程，在雌性大鼠出生后的个体发育过程中，研究了乙醚应激对血浆GH水平的影响。乙醚应激对1日龄幼崽的血浆GH水平无影响。在3日龄和9日龄幼崽中发现血浆GH明显下降，用生长抑素抗血清处理3日龄动物可阻止这种反应。在12日龄、15日龄、18日龄和21日龄大鼠中未观察到乙醚应激对血浆GH有影响。用生长抑素抗血清处理完整的12日龄幼崽，在基础条件下可使血浆GH水平升高。在30日龄和成年动物中再次观察到乙醚应激对血浆GH的抑制作用。结论是，3日龄大鼠的下丘脑能够释放足够的生长抑素以在应激后抑制GH分泌。在12 - 18天期间观察到垂体不应期阶段：乙醚应激以及TRH注射（我们之前的观察结果）均未能影响雌性幼崽的血浆GH，这可能是由于基础条件下生长抑素分泌较高以及（或）垂体释放GH的能力较低。提示GH分泌的调节在出生后第21天之前尚未成熟。
