Short-Term Effect of Epinephrine on Glucose 6-Phosphate Dehydrogenase Activity in Isolated Human Hepatocytes



Haghighi B¹ ; Toori SH¹ ; Noie N¹ Show Affiliations
Source: Iranian Journal of Medical Sciences Published:1998

Abstract

The short-term effect of epinephrine on glucose 6-phosphate dehydrogenase (G6PD) activity of isolated human hepatocytes was examined. Epinephrine increased the enzyme activity at concentrations between 10-8 M and 10-2 M (98%). Maximum effect of epinephrine was obtained after 20 minutes incubation after which the enzyme activity declined. Alprenolol, a β-adrenoceptor blocker, abolished the stimulatory effect of epinephrine on G6PD activity, whereas α-adrenoceptor antagonist, phentolamine, or the agonist, phenylephrine, did not alter the hormone effect. Dibutyryl-cAMP alone stimulated the enzyme activity by maximum of 71%. The presence of cAMP phosphodiesterase inhibitor, aminophylline, together with epinephrine increased the enzyme stimulation (18%). The results suggested that epinephrine exerts its effect on human hepatocyte through β-adrenoceptor activation and cAMP is involved in the mechanism by which G6PD is regulated.