We developed an infant circulation model which incorporates an accurate myocardial cell model including a beta adrenergic system. The beta adrenergic system is essential for the response reproduction of the baroreflex control system. The proposed model was constructed by modifying the parameters of a human adult circulation model with the aid of a guinea pig myocardial cell model, whose baselin...

Although quinidine is known to have antiadrenergic effects in the cardiovascular system, the precise mechanism by which it exerts these effects is not well defined. We asked whether quinidine binds directly to adrenergic receptors. Radioligand-binding assays were used to identify <*i -adrenergic receptors ([H]prazosin-binding sites) on membranes prepared from rat heart and kidney, a2-adrenergic...

BACKGROUND Mechanical unloading of the failing human heart with a left ventricular assist device (LVAD) results in clinically documented reversal of chamber dilation and improvement of cardiac function. We tested the hypothesis that LVAD support normalizes the ability of cardiac muscle to respond to sympathetic nervous system stimulation by reversing the downregulation of beta-adrenergic recept...

The discovery by Janakidevi et al.' that the ciliated protozoan Tetrahymena contains epinephrine and norepinephrine led Blum et al.2 to examine the effect of reserpine on these ciliated protozoa. It was found that reserpine inhibited the growth of these cells and depleted the catecholamine content. The growth inhibition was partially reversed by addition of glucose to the medium.2 These observa...

The sympathetic nervous system regulates cardiovascular function by activating adrenergic receptors in the heart, blood vessels and kidney. Alpha2-adrenergic receptors are known to have a critical role in regulating neurotransmitter release from sympathetic nerves and from adrenergic neurons in the central nervous system; however, the individual roles of the three highly homologous alpha2-adren...

THE CONCEPT that drugs react with specific receptors in living tissues to produce pharmacologic effects is believed to have originated with Langley in 19051 although Ehrlich and others had certainly conceived of specific drug-cellular interactions. Today receptors have achieved such status amnong pharmacologists to be almost commonplace in spite of the fact that their identity has not been esta...

Recent demonstration that the level of sympathetic nervous drive to the failing heart in patients with severe heart failure is a major determinant of prognosis, and that mortality in heart failure is decreased by beta-adrenergic blockade with carvedilol, indicates the clinical relevance of cardiac neuroscience research. Important initial findings were observations that the plasma concentration ...

Although quinidine is known to have antiadrenergic effects in the cardiovascular system, the precise mechanism by which it exerts these effects is not well defined. We asked whether quinidine binds directly to adrenergic receptors. Radioligand-binding assays were used to identify <*i -adrenergic receptors ([H]prazosin-binding sites) on membranes prepared from rat heart and kidney, a2-adrenergic...

Abnormalities in activity of the endothelin (ET) system have been widely reported in a number of cardiovascular disease states such as hypertension and heart failure. Although the vascular responses to ET are well established, the interaction between ET and other important modulators of blood pressure, such as the sympathetic nervous system, are less understood. Previous reports implicate ET si...