H. Abe et al., EFFECT OF A BETA(3)-ADRENERGIC AGONIST, BRL35135A, ON GLUCOSE-UPTAKE IN RAT SKELETAL-MUSCLE IN-VIVO AND IN-VITRO, Journal of Endocrinology, 139(3), 1993, pp. 479-486
The effects of the beta(3)-agonist, BRL35135A, on glucose uptake in th
e peripheral tissues of the rat, including skeletal muscle, were studi
ed using the 2-[H-3]deoxyglucose method in anaesthetized adult animals
. Intravenous infusion of the beta(3)-agonist dose-dependently increas
ed the rate constant of glucose uptake in three types of skeletal musc
le, brown adipose tissue, white adipose tissue, heart and diaphragm, b
ut 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 gi
ven at more than 25 mu g/kg per h. To ascertain whether the effect of
the beta(3)-agonist on glucose uptake in skeletal muscle is mediated b
y 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 BRL3
5135A) significantly increased glucose transport in a dose-dependent m
anner, with maximum stimulation at 100 pmol/l. These results demonstra
te that glucose uptake in skeletal muscle can be enhanced through the
mediation of beta(3)-adrenoceptors present in the tissue.