McCutcheon S N, Bauman D E
J Dairy Sci. 1986 Jan;69(1):44-51. doi: 10.3168/jds.S0022-0302(86)80368-X.
Bovine growth hormone was administered to four Holstein cows (late lactation) in a Latin square. Treatments were 1) control, subcutaneous injection of placebo, 2) subcutaneous injection of 25 IU growth hormone on alternate days, 3) daily subcutaneous injection of 25 IU growth hormone, and 4) continuous subcutaneous infusion of 25 IU/d growth hormone. Intravenous challenges of epinephrine and thyrotropin-releasing hormone were administered separately on the 1st d after a 12-d interval of growth hormone treatment. Baseline concentrations of nonesterified fatty acids in plasma were not affected by growth hormone treatment. However, release of nonesterified fatty acids to epinephrine challenge was positively related to amount of growth hormone in plasma during treatment and was correlated with milk fat yield and milk energy secretion. Growth hormone release following thyrotropin-releasing hormone was negatively related to amount of growth hormone in plasma during treatment. Release of prolactin to thyrotropin-releasing hormone challenge was not related to average daily dose of exogenous growth hormone. The galactopoeitic action of growth hormone may be partly attributable to its effects on responsiveness of adipose tissue to a lipolytic stimulus but apparently is not associated with changes of pituitary sensitivity to thyrotropin-releasing hormone. Results are consistent with growth hormone functioning as a homeorhetic control of nutrient partitioning.
以拉丁方设计，给4头荷斯坦奶牛（泌乳后期）注射牛生长激素。处理方式为：1）对照，皮下注射安慰剂；2）每隔一天皮下注射25国际单位生长激素；3）每天皮下注射25国际单位生长激素；4）每天连续皮下输注25国际单位/天生长激素。在生长激素处理12天的间隔期后的第1天，分别单独进行肾上腺素和促甲状腺激素释放激素的静脉注射刺激。生长激素处理未影响血浆中非酯化脂肪酸的基线浓度。然而，肾上腺素刺激引起的非酯化脂肪酸释放与处理期间血浆中生长激素的量呈正相关，并且与乳脂产量和乳能量分泌相关。促甲状腺激素释放激素刺激后生长激素的释放与处理期间血浆中生长激素的量呈负相关。促甲状腺激素释放激素刺激引起的催乳素释放与外源性生长激素的平均日剂量无关。生长激素的催乳作用可能部分归因于其对脂肪组织对脂解刺激反应性的影响，但显然与垂体对促甲状腺激素释放激素敏感性的变化无关。结果与生长激素作为营养分配的同态调节因子的功能一致。
