Increased α2‐ but similar β‐adrenergic receptor activities in subcutaneous gluteal adipocytes from females compared with males-猫眼课题宝

与男性相比，女性皮下臀肌脂肪细胞中 α2 受体活性增加，但 β 肾上腺素受体活性相似

DOI：

10.1111/j.1365-2362.1986.tb01346.x

发表时间：

1986

期刊：

European Journal of Clinical Investigation

影响因子：

5.5

通讯作者：

中科院分区：

医学3区

文献类型：

作者：

B. Richelsen

抽象。在雌性和雄性动物臀部皮下脂肪细胞中研究了α 2和β-肾上腺素能结合和作用。β选择性拮抗剂[3 H]二氢阿普洛尔和α2选择性拮抗剂[3 H]育亨宾分别用于鉴定β和α2受体。通过测量异丙肾上腺素（β受体激动剂）和可乐定（α2受体激动剂）诱导的甘油释放来确定这些受体介导的生物学效应。该研究由健康志愿者（18名女性和15名男性）组成。与男性相比，女性脂肪细胞的α2-受体结合增加了73%（P <0.01）。根据Scatchard分析，确定结合增加是由于受体数量增加（438 v. 262 fmol mg-1蛋白，P < 0·001），Kd不变（1·18 v. 1·35 nmol l-1，P > 0·05）。女性和脂肪细胞中α2受体结合的增加与可乐定的敏感性显著增加（P < 0·05）和最大抗脂解作用（P < 0·05）相关。雌性和雄性脂肪细胞中的β受体结合相似。然而，异丙肾上腺素对雌性脂肪细胞的脂解作用明显更强（P < 0·01）。由于茶碱和腺苷脱氨酶的组合在雌性脂肪细胞中也具有显著更多的脂解作用，因此异丙肾上腺素的增强作用似乎是由于与激素β受体结合不直接相关的机制。最后，混合的β-和α2-受体激动剂肾上腺素对脂解显示出双相作用，在低浓度（< 500 nmol l-1）下具有刺激作用，在较高浓度（> 1 μmol l-1）下具有明显的抑制作用。但在低浓度肾上腺素作用下，雌性臀肌脂肪细胞的脂解作用显著降低（P <0.05），而抑制作用在雌性和雄性之间相似。由此得出结论，女性臀脂肪细胞比男性脂肪细胞具有更多的α2-肾上腺素能受体。这种结合的增加伴随着可乐定的抗脂解作用的增强和低浓度肾上腺素的脂解作用的降低。因此，这表明女性臀部脂肪细胞中α2-受体的增加可能与女性在该区域增加脂肪的趋势有关。

Abstract. α 2 and β‐adrenergic binding and action were studied in subcutaneous adipocytes from the gluteal region in females and males. The β‐selective antagonist [3H]dihydroalprenolol and the α2‐selective antagonist [3H]yohimbine were used to identify the β‐ and the α2‐receptor, respectively. The biological effects mediated by these receptors were determined by measuring the glycerol release induced by isoproterenol (β‐receptor agonist) and by clonidine (α2‐receptor agonist). The study consisted of health volunteers (eighteen females and fifteen males). Compared to men the α2‐receptor binding was increased by 73% (P < 0·01) in adipocytes from females. From Scatchard analysis it was determined that the increased binding was due to an increased receptor number (438 v. 262 fmol mg‐1 protein, P < 0·001) with unaltered Kd (1·18 v. 1·35 nmol l‐1, P > 0·05). This increased α2‐receptor binding in female and adipocytes was associated with a significantly increased sensitivity (P < 0·05) and maximal antilipolytic effect of clonidine (P < 0·05). The β‐receptor binding was similar in adipocytes from females and males. However, isoproterenol was significantly more lipolytic in female adipocytes (P < 0·01). Since the combination of theophylline and adenosine deaminase also was significantly more lipolytic in female adipocytes the enhanced effect of isoproterenol then seemed to be due to mechanisms not directly related to the hormone‐β‐receptor binding. Finally, the mixed β‐ and α2‐receptor agonist, adrenaline showed biphasic effects on lipolysis, with stimulatory effect at low concentrations (< 500 nmol l‐1) and pronounced inhibitory effect at higher concentrations (> 1 μmol l‐1). However, at low concentrations of adrenaline the lipolytic effect was significantly reduced in female gluteal adipocytes (P < 0·05), whereas the inhibitory effect was similar between females and males. It is concluded that female gluteal adipocytes possessed more α2‐adrenergic receptors than male adipocytes. This increased binding was accompanied by enhanced antilipolytic effect of clonidine and reduced lipolytic effect of low concentrations of adrenaline. Thus, it is suggested that the increased α2‐receptors in female gluteal adipocytes might be related to the enhanced tendency for females to accumlate fat in this region.

Agonist versus antagonist binding to alpha-adrenergic receptors.