Effect of reserpine pretreatment on avian erythrocyte carbonic anhydrase activation by isoproterenol.
We studied the action of beta-adrenergic agonists on Japanese quail erythrocyte carbonic anhydrase (CA) in vitro. Earlier we had reported that epinephrine increased CA activity by 14%; the present study focused on an attempt to increase the size of this response. Washed erythrocytes from reserpine-treated (1 mg/kg daily i.m. for 3 days) and control birds were incubated for 40 min in the presence of isoproterenol 10(-6) mol/l. The activity of CA expressed as Wilbur-Anderson units/mg hemoglobin was increased by as much as 42% in reserpine-treated birds over the control depending on the conditions. Addition of 10(-5) mol/l of the beta-adrenergic antagonist propranolol inhibited the isoproterenol-induced effect in nonreserpinized birds. We conclude that pretreatment with reserpine, which was accompanied by a fall in plasma catecholamine levels, particularly epinephrine levels, enhanced the activation of CA by isoproterenol.
Department of Pharmacology, Texas Tech University Health Sciences Center, Lubbock 79430.
I N
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Igbo
C E
CE
Reigel
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Greene
A D
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Kenny
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002256:Carbonic Anhydrases / Q000378:metabolism*; D003370:Coturnix; D004789:Enzyme Activation / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects* / Q000201:enzymology*; D007545:Isoproterenol / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008297:Male; D011433:Propranolol / Q000494:pharmacology; D012110:Reserpine / Q000494:pharmacology*
D012110:Reserpine; D011433:Propranolol; D002256:Carbonic Anhydrases; D007545:Isoproterenol