Alpha- and beta-adrenergic receptors were studied by measuring the binding of 3H-dihydroergocryptine and 3H-dihydroalprenolol, respectively, to membranes prepared from homogenized rabbit iris--ciliary bodies. The binding of 3H-dihydroergocryptine appears to be specific for alpha-adrenergic receptors, since adrenergic agents displace this radioligand with the following order of potency: phentola...

Influences of central alpha-2 adrenergic agonists on thyrotropin-releasing hormone (TRH)-stimulated gastric acid secretion were examined in the perfused stomach of anesthetized rats. Clonidine, an alpha-2 adrenergic agonist, given subcutaneously or intracerebroventricularly inhibited the gastric acid secretion stimulated by intracerebroventricular TRH. Intracerebroventricular injection of norep...

Quantitative in vitro autoradiography was used to determine and compare the areal and laminar distribution of the major dopaminergic, adrenergic, and serotonergic neurotransmitter receptors in 4 cytoarchitectonic regions of the prefrontal cortex (Walker's areas 12, 46, 9, and 25) in adult rhesus monkeys. The selective ligands, 3H-SCH-23390, 3H-raclopride, 3H-prazosin, and 3H-clonidine were used...

Activation of renal alpha-adrenergic receptors induces vasoconstriction, proximal tubular reabsorption of sodium, and inhibition of renal release. Excesses of these effects are present in varying degrees in animal models of, and in patients with, "essential" hypertension. Since essential hypertension is genetically determined, we sought abnormalities of renal alpha-adrenergic receptors in the O...

Pyridostigmine bromide (PB) is a reversible cholinesterase inhibitor used routinely in the treatment of myasthenia gravis and recently by the US Army as a prophylactic agent against potential nerve gas attack in the Persian Gulf War. Pyridostigmine has been implicated as one of several possible causative factors associated with Persian Gulf illnesses. To investigate toxic interactions between P...

The objective was to determine whether recombinant bovine somatotropin (rbST) enhanced live performance,skeletal muscle biological activity, and beta-adrenergic receptor expression of feedlot heifers during the finishing phase. Heifers (n = 16; initial body weight 457 ± 3 kg) were randomly assigned pens (4 pens/treatment; 2 heads/pen) treatment: (1) no rbST (Control); (2) 500 mg/hd sometribove ...

Different beta 1 and 2 adrenergic receptors agonists might have various biological and physiological effects on fish species. An experiment was designed to study the effects of feeding ractopamine, terbutaline and metaproterenol; as beta1, beta2 and less selective beta2 adrenergic receptor agonists, respectively; on body weight gain, feed conversion rate, concentration of biochemical parameters...

Fifty percent of adult canine Purkinje fibers manifest a decrease in automaticity in response to alpha 1-adrenergic stimulation with 10(-10)-10(-8) M norepinephrine (NE), and 50% manifest an increase. In contrast, most neonatal Purkinje fibers show an increase in automaticity in response to these concentrations of NE. We studied the modulation of NE effects, using the subtype selective alpha 1-...