The effect of catecholamines (epinephrine, norepinephrine, isoproterenol, and phenylephrine) on cyclic adenosine 3′:5′-monophosphate (cAMP) level in isolated catfish (Ictalurus melas) liver cells was studied in the presence or absence of α (phentolamine) and β (propranolol)-receptor antagonists. All catecholamines increased the hepatocyte cAMP level; the rank of their potency was epinephrine = isoproterenol > norepinephrine > phenylephrine. Propranolol completely blocked the catecholamine effect; phentolamine was ineffective. Results confirm previous findings (L. Brighenti, A. C. Puviani, M. E. Gavioli, and C. Ottolenghi, 1987, Gen. Comp. Endocrinol. 66, 306-313) that epinephrine and norepinephrine act via β-receptor activation. However, the comparison of the effects of isoproterenol and phenylephrine on cAMP with those on phosphorylase a and on glycogen breakdown suggests that a more complex mechanism is possibly involved in the catecholamine effect on catfish glycogenolysis. © 1987.
Brighenti L., Puviani A.C., Gavioli M.E., Fabbri E., Ottolenghi C. (1987). Catecholamine effect on cyclic adenosine 3′:5′-monophosphate level in isolated catfish hepatocytes. GENERAL AND COMPARATIVE ENDOCRINOLOGY, 68(2), 216-223 [10.1016/0016-6480(87)90032-3].
Catecholamine effect on cyclic adenosine 3′:5′-monophosphate level in isolated catfish hepatocytes
Fabbri E.
Conceptualization
;
1987
Abstract
The effect of catecholamines (epinephrine, norepinephrine, isoproterenol, and phenylephrine) on cyclic adenosine 3′:5′-monophosphate (cAMP) level in isolated catfish (Ictalurus melas) liver cells was studied in the presence or absence of α (phentolamine) and β (propranolol)-receptor antagonists. All catecholamines increased the hepatocyte cAMP level; the rank of their potency was epinephrine = isoproterenol > norepinephrine > phenylephrine. Propranolol completely blocked the catecholamine effect; phentolamine was ineffective. Results confirm previous findings (L. Brighenti, A. C. Puviani, M. E. Gavioli, and C. Ottolenghi, 1987, Gen. Comp. Endocrinol. 66, 306-313) that epinephrine and norepinephrine act via β-receptor activation. However, the comparison of the effects of isoproterenol and phenylephrine on cAMP with those on phosphorylase a and on glycogen breakdown suggests that a more complex mechanism is possibly involved in the catecholamine effect on catfish glycogenolysis. © 1987.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
