McCann J P, Reimers T J
J Anim Sci. 1985 Sep;61(3):612-8. doi: 10.2527/jas1985.613612x.
Changes in serum concentrations of glucose and insulin after iv injection of a low (20 mU/kg) and high (200 mU/kg) dose of bovine insulin were used to quantify insulin resistance and calculate kinetic variables of injected insulin, respectively, in four obese and four lean heifers. Serum samples from jugular venous blood were collected 60, 45, 30, 15 and 1 min before and 2.5, 5, 10, 20, 30, 40, 60, 80, 100, 120, 150, 180, 210 and 240 min after each treatment. Mean (+/- SE) pretreatment concentration of insulin (microU/ml) was higher (P less than .01) in obese (50 +/- 6.6) than lean (20 +/- 1.8) heifers, even though glucose concentrations were similar in both groups (71 +/- 2.9 mg/100 ml). Concentrations of insulin after each treatment were similar in both groups and returned to pretreatment values by 60 and 120 min after injection of the low and high doses, respectively. Glucose concentrations during the first 40 min after treatment with the low dose were lower (P less than .05) in lean than obese heifers, but were similar in both groups during the first 40 to 60 min after the high dose of insulin. The high insulin dose decreased (P less than .05) glucose concentrations below those of the low dose in each group, but the difference was greater (P less than .01) in obese than lean heifers. These results indicated that obese heifers were insensitive to the glucoregulatory effects of exogenous insulin, although the maximum responses to insulin were similar.(ABSTRACT TRUNCATED AT 250 WORDS)
通过静脉注射低剂量（20 mU/kg）和高剂量（200 mU/kg）的牛胰岛素后，测定血清葡萄糖和胰岛素浓度的变化，分别用于量化四头肥胖小母牛和四头瘦小小母牛的胰岛素抵抗，并计算注射胰岛素的动力学变量。在每次治疗前60、45、30、15和1分钟以及治疗后2.5、5、10、20、30、40、60、80、100、120、150、180、210和240分钟采集颈静脉血的血清样本。肥胖小母牛（50±6.6）的胰岛素预处理平均浓度（微U/ml）高于瘦小小母牛（20±1.8）（P<0.01），尽管两组的葡萄糖浓度相似（71±2.9 mg/100 ml）。两组每次治疗后的胰岛素浓度相似，分别在注射低剂量和高剂量后60分钟和120分钟恢复到预处理值。低剂量治疗后前40分钟，瘦小小母牛的葡萄糖浓度低于肥胖小母牛（P<0.05），但在高剂量胰岛素治疗后的前40至60分钟，两组相似。高胰岛素剂量使每组的葡萄糖浓度低于低剂量（P<0.05），但肥胖小母牛的差异更大（P<0.01）。这些结果表明，肥胖小母牛对外源性胰岛素的血糖调节作用不敏感，尽管对胰岛素的最大反应相似。（摘要截短至250字）
