牛生长激素和食物剥夺对泌乳期奶牛脂肪组织中β-肾上腺素能和A1腺苷受体结合的影响。

Effect of bovine somatotropin and food deprivation on beta-adrenergic and A1 adenosine receptor binding in adipose tissue of lactating cows.

作者信息

Houseknecht K L, Bauman D E, Carey G B, Mersmann H J

机构信息

Department of Animal Science, Cornell University, Ithaca, NY, USA.

出版信息

Domest Anim Endocrinol. 1995 Oct;12(4):325-36. doi: 10.1016/0739-7240(95)00029-e.

DOI:10.1016/0739-7240(95)00029-e

PMID:8575165

Abstract

Lactating Holstein cows were used to assess the effect of bovine somatotropin (bST; n = 8) and fasting (FAST; n = 4) on ligand binding to beta-adrenergic (BAR) and Type-1 adenosine (A1R) receptors in adipose tissue. Cows received exogenous bST (sometribove; 40 mg/d) or no hormone (control) for 4 d in a single-reversal design with a 7-d interval between treatment periods. Subcutaneous adipose tissue biopsies were taken on day 4 of each treatment. Eight d after the bST regimen, 4 cows were fasted for 3 d and adipose biopsies were taken. Ligand binding was quantified with a postnuclear, total adipose tissue membrane preparation (100,000 x g pellet). Binding to BAR and A1R was assessed with the antagonists [125I]iodocyanopindolol (ICP) and [3H]8-cyclopentyl-1,3-dipropylxanthine (DCPCX), respectively. The binding affinity (Kd) of BAR for ICP was not affected by bST but was enhanced by FAST; maximal binding (Bmax) was increased with bST treatment (P < 0.06) and reduced by FAST (61%, P < 0.01). Kd values for DCPCX binding to A1R were not changed by bST or FAST. bST did not affect Bmax for A1R; however, FAST reduced the Bmax by 38%. Data highlight the differential regulation of BAR and A1R by bST and FAST.

摘要

选用泌乳期荷斯坦奶牛来评估牛生长激素（bST；n = 8）和禁食（FAST；n = 4）对脂肪组织中β-肾上腺素能（BAR）和1型腺苷（A1R）受体配体结合的影响。奶牛采用单逆转设计接受外源性bST（司美格鲁肽；40 mg/d）或不接受激素（对照），治疗期之间间隔7天，持续4天。在每种治疗的第4天采集皮下脂肪组织活检样本。bST治疗方案8天后，4头奶牛禁食3天并采集脂肪活检样本。用核后全脂肪组织膜制剂（100,000×g沉淀）对配体结合进行定量。分别用拮抗剂[125I]碘氰吲哚洛尔（ICP）和[3H]8-环戊基-1,3-二丙基黄嘌呤（DCPCX）评估与BAR和A1R的结合。BAR对ICP的结合亲和力（Kd）不受bST影响，但禁食可增强该亲和力；最大结合量（Bmax）在bST治疗后增加（P < 0.06），禁食使其降低（61%，P < 0.01）。DCPCX与A1R结合的Kd值不受bST或禁食影响。bST不影响A1R的Bmax；然而，禁食使Bmax降低了38%。数据突出了bST和禁食对BAR和A1R的差异调节作用。