Alpha-adrenergic potentiation of beta-adrenergic stimulation of rat pineal N-acetyltransferase: Studies using cirazoline and fluorine analogs of norepinephrine

doi:10.1016/0006-2952(84)90006-6

Biochemical Pharmacology

Volume 33, Issue 24, 15 December 1984, Pages 3947-3950

https://doi.org/10.1016/0006-2952(84)90006-6 Get rights and content

Abstract

Recent evidence indicates that melatonin production is controlled by norepinephrine acting via alpha₁ -and beta₁ -adrenoceptors on pinealocytes; activation of alpha₁ -adrenoceptors appears to potentiate the effects of beta₁ -adrenoceptor activation. However, alpha-adrenergic potentiation of beta₁ -adrenergic activation has been demonstrated with only one alpha-adrenergic agonist. For this reason, this issue was reinvestigated using two other alpha-adrenergic agonists, 6-fluoronorepinephrine and cirazoline. Both compounds, which were found to have a high affinity for pineal alpha₁-adrenoceptors, potentiated the stimulatory effects of isoproterenol on pineal N-acetyltransferase. 6-Fluoro-norepinephrine also potentiated the stimulation of N-acetyltransferase activity produced by another beta-adrenergic agonist, 2-fluoronorepinephrine. These findings support the hypothesis that pineal N-acetyltransferase activity is regulated by norepinephrine acting through both alpha₁ -and beta₁ - adrenoceptors.

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Alpha-adrenergic potentiation of beta-adrenergic stimulation of rat pineal N-acetyltransferase: Studies using cirazoline and fluorine analogs of norepinephrine

Abstract

Biochem. Pharmac.

Neuropharmacology

Molec. cell. Endocr.

Biochem. Pharmac.