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...

The isolated mouse vas deferens possesses an adrenergic excitatory motor innervation which can be inhibited by low concentrations of morphine (ID50=0.5 muM). This effect of morphine is mediated by specific receptors which are blocked by naloxone. Activation of the morphine receptors inhibits noradrenaline release. It is concluded that adrenergic neurotransmission in the mouse vas deferens diffe...

Hormones and most drugs initiate their biological actions by interacting with receptor macromolecules in or on cells. Of the receptors which are located in the plasma membranes of cells, many are coupled to specific effector molecules via intermediary coupling proteins. These are termed “G”-proteins, because they bind and hydrolyze the guanine nucleotide, GTP (1). Among the biological agents wh...

Background. In chronic heart failure, the positive inotropic effects of -adrenergic receptor agonists are greatly reduced, in part as a result of two alterations of the cardiac -adrenergic receptors: loss of their function (receptor uncoupling) and reduction of their number (downregulation). In vitro studies have shown that a major mechanism leading to fadrenergic receptor uncoupling involves p...

Dobutamine and its stereoisomers were evaluated for alpha and beta adrenergic activities in vitro. The racemate and the (--)-isomer were found to be potent partial agonists of alpha adrenergic receptors in rat aorta. The (+)-isomer lacked alpha agonist activity. The affinities of (+/-)-, (+)- and (--)-dobutamine for the alpha adrenergic receptor were high (--log KB values of 7.01, 7.02 and 7.07...

H]Dihydroergocryptine ([H]DHE) binds to sites in membranes derived from rat myocardium that have the characteristics expected of a-adrenergic receptors. The binding is saturable with 41 fmol [H]DHE bound per mg of protein and of high affinity with KD = 2.9 niu. The binding is rapid and readily reversible. Adrenergic agonists compete with [H]DHE for binding in the order: epinephrine > norepineph...

In Chagas disease serious cardiac dysfunction can appear. We specifically studied the cardiac function by evaluating: ventricle contractile force and norepinephrine response, affinity and density of beta-adrenergic receptors, dynamic properties of myocardial membranes, and electrocardiography. Albino swiss mice (n = 250) were infected with 55 trypomastigotes, Tulahuen strain and studied at 35, ...

An azide analog, 2-[4-(4-azidobenzoyl)piperazin-1-yl]-4-amino-6, 7-dimethoxyquinazoline (CP59,430), of the highly selective alpha 1-adrenergic receptor antagonist prazosin was synthesized and its effects on rat hepatic membrane and affinity-purified alpha 1-adrenergic receptor preparations were examined. CP59,430 behaved as a competitive antagonist before photolysis. When the membrane or purifi...