Abe H, Minokoshi Y, Shimazu T
Department of Medical Biochemistry, Ehime University School of Medicine, Japan.
J Endocrinol. 1993 Dec;139(3):479-86. doi: 10.1677/joe.0.1390479.
The effects of the beta 3-agonist, BRL35135A, on glucose uptake in the peripheral tissues of the rat, including skeletal muscle, were studied using the 2-[3H]deoxyglucose method in anaesthetized adult animals. Intravenous infusion of the beta 3-agonist dose-dependently increased the rate constant of glucose uptake in three types of skeletal muscle, brown adipose tissue, white adipose tissue, heart and diaphragm, but not in the brain, spleen or lung. Although infusion of the beta 3-agonist did not change the plasma concentration of glucose appreciably, it caused an increase in the plasma concentration of insulin when given at more than 25 micrograms/kg per h. To ascertain whether the effect of the beta 3-agonist on glucose uptake in skeletal muscle is mediated by insulin, glucose uptake into soleus muscle isolated from young rats was also measured in vitro using different concentrations of the beta 3-agonist. The beta 3-agonist BRL37344 (an active metabolite of BRL35135A) significantly increased glucose transport in a dose-dependent manner, with maximum stimulation at 100 pmol/l. These results demonstrate that glucose uptake in skeletal muscle can be enhanced independently of the action of insulin, probably through the mediation of beta 3-adrenoceptors present in the tissue.
利用2-[³H]脱氧葡萄糖法，在麻醉的成年动物中研究了β3-激动剂BRL35135A对大鼠外周组织（包括骨骼肌）葡萄糖摄取的影响。静脉输注β3-激动剂可使三种类型的骨骼肌、棕色脂肪组织、白色脂肪组织、心脏和膈肌中葡萄糖摄取的速率常数呈剂量依赖性增加，但对脑、脾或肺无此作用。尽管输注β3-激动剂并未明显改变血浆葡萄糖浓度，但当以每小时超过25微克/千克的剂量给药时，会导致血浆胰岛素浓度升高。为了确定β3-激动剂对骨骼肌葡萄糖摄取的作用是否由胰岛素介导，还使用不同浓度的β3-激动剂在体外测量了从幼鼠分离的比目鱼肌中的葡萄糖摄取。β3-激动剂BRL37344（BRL35135A的活性代谢产物）以剂量依赖性方式显著增加葡萄糖转运，在100皮摩尔/升时达到最大刺激。这些结果表明，骨骼肌中的葡萄糖摄取可能通过组织中存在的β3-肾上腺素能受体介导，独立于胰岛素的作用而增强。
