To evaluate the adrenergic regulation of lower esophageal sphincter (LES) function, LES pressure, LES relaxation during swallowing, and blood pressure were measured in the anesthetized opossum, Didelphis virginiana, during intravenous administration of alpha and beta adrenergic agonists and antagonists. Studies were done in controls and animals adrenergically denervated with 6-hydroxydopamine. ...

BACKGROUND Mammalian spermatozoa have been shown to have beta(1,2,3)- and alpha(2A)-adrenergic receptors, the former functioning only in uncapacitated spermatozoa and the latter only in capacitated cells. Cathine, an amphetamine-related metabolite of a compound found in Catha edulis leaves, accelerates capacitation and inhibits spontaneous acrosome loss by regulating cAMP production. This study...

The intracellular adenine nucleotide pool of rabbit iris-ciliary body was labelled by uptake of 3H-adenine in vitro. A variety of agents were tested for their ability to stimulate or inhibit the incorporation of radioactivity into cyclic AMP formed from ATP labelled with 3H-adenine. Isoproterenol, vasoactive intestinal peptide, forskolin, and prostaglandin E2 stimulated incorporation of label 3...

Preincubation with an alpha 2-adrenergic agonist sensitized subsequent forskolin- and vasoactive intestinal peptide-stimulated cyclic AMP production in HT29 cells, a human colonic adenocarcinoma cell line. Preincubation with somatostatin, another agonist negatively coupled to adenylate cyclase, sensitized forskolin-stimulated cyclic AMP production to a lesser extent. alpha 2-Adrenergic agonist ...

There is convincing evidence to suggest that there are direct effects of adrenergic agents on renal tubules. During the last several years, considerable progress has been made in determining the type of adrenoceptors present in renal tubular cells through the use of radioligand binding and signal transduction methods. The receptor data are summarized in table 6. Almost all major nephron segment...