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...