Spencer G S, Berry C, Johnston S
Ruakura Agricultural Centre, Hamilton, New Zealand.
Domest Anim Endocrinol. 1991 Oct;8(4):555-63. doi: 10.1016/0739-7240(91)90025-f.
The result of alterations in the levels of CCK, in the blood and in the cerebrospinal fluid, on the functioning of the growth hormone axis has been examined in sheep. Male Coopworth sheep of about 40 kg liveweight were given various doses of CCK either intracerebroventricularly (icv) or intravenously (iv). Other similar sheep were given various doses of a CCK antagonist (loxiglumide) by the same routes. Bolus iv administration of either 35 micrograms or 200 micrograms of CCK had no effect on plasma GH levels. When given icv, however, CCK resulted in a marked (P less than 0.01) prolonged depression in plasma GH levels. The decrease in GH secretion could be partially attenuated by concurrent administration of loxiglumide, but was completely unaffected by concurrent administration of antisomatostatin serum icv. Loxiglumide alone had no effect on plasma GH levels when given at up to 200 micrograms icv, but intravenous administration of 8 mg of the CCK antagonist resulted in an increase in plasma GH concentrations (P less than 0.05). Plasma levels of somatostatin, glucose and cortisol were unaffected by both icv and iv administration of CCK. These results show that CCK can have a strong GH-inhibiting effect in the brain. Furthermore, this effect seems to be independent of hypothalamic somatostatin, suggesting another GH-inhibiting system exists.
在绵羊身上研究了血液和脑脊液中胆囊收缩素（CCK）水平的改变对生长激素轴功能的影响。给体重约40千克的雄性库泊华斯绵羊经脑室（icv）或静脉（iv）给予不同剂量的CCK。其他相似的绵羊经相同途径给予不同剂量的CCK拮抗剂（洛谷酰胺）。静脉推注35微克或200微克CCK对血浆生长激素（GH）水平无影响。然而，经脑室给予CCK时，会导致血浆GH水平显著（P<0.01）且持续时间延长的降低。同时给予洛谷酰胺可部分减轻GH分泌的减少，但经脑室同时给予抗生长抑素血清对其完全无影响。经脑室给予高达200微克洛谷酰胺时，单独使用洛谷酰胺对血浆GH水平无影响，但静脉给予8毫克CCK拮抗剂会导致血浆GH浓度升高（P<0.05）。经脑室和静脉给予CCK均不影响生长抑素、葡萄糖和皮质醇的血浆水平。这些结果表明，CCK在大脑中可产生强烈的生长激素抑制作用。此外，这种作用似乎独立于下丘脑生长抑素，提示存在另一种生长激素抑制系统。
