Propofol has been shown to attenuate beta-adrenoreceptor-mediated signal transduction in cardiomyocytes. Cyclic adenosine monophosphate (cAMP) is an essential second messenger of beta-signal transduction, while olprinone, a phosphodiesterase-III inhibitor, improves poor cardiac performance by increasing cAMP levels. In the present study, we investigated the effects of olprinone toward the reduc...

Isoproterenol infusion (0.1 /ig/kg per min) into the renal artery of the cat induced an increase in plasma renin concentration (PRC) from 14.3 ± 5.7 (mean ± SE) ng angiotensin I/ml per hr to 56.8 ± 7.7 after 70 minutes {P < 0.05) and an increase in catecholamine secretion rate from 38.7 ± 6.0 ng/kg per 10 min to 180.0 ± 40.0 after 70 minutes (P < 0.001). Intravenous infusion of the same dose of...

The effect of alpha-tocopherol pretreatment on lipid peroxidation and antioxidant status in isoproterenol induced myocardial infarction was studied in rats. Isoproterenol administered rats showed a significant increase in lipid peroxides in serum, heart and aorta. A significant increase in serum iron level with a significant decrease in iron binding capacity was also observed. The levels of ant...

SCHNEYER, L. H., AND TIRASAKDI THAVORNTHON. IsoproterenoZinduced stimulation of sodium absorption in perfused saliuary duct. Am. J. Physiol. 224(l): 136-139. 1973.-Administration of isoproterenol, to rats, as a single intraperitoneal dose of approximately 13 pg/kg body wt produced a sustained elevation in net efflux of Na from the lumen of the submaxillary main excretory duct during perfusion w...

The effect of aspirin on isoproterenol-induced changes related to myocardial damage was studied in rats. Rats were treated with aspirin (1.2 mg/100 g/day) orally, daily for a period of one month. Isoproterenol (20 mg/100 g, sc, twice at an interval of 24 hr) was administered. In isoproterenol treated rats marked increase in cholesterol, free fatty acids and triglycerides in both serum and heart...

Adenosine is an important inhibitory neuromodulator in the CNS, yet the sources of extracellular adenosine have yet to be well characterized. In this study we show that beta-adrenergic stimulation of cortical cultures results in the extracellular accumulation of cAMP as well as adenosine, and that the extracellular adenosine derives from extracellular cAMP. The concentration dependence of isopr...

Cardiac hypertrophy is often associated with an increased sympathetic drive, and both in vitro and in vivo studies have demonstrated the development of cardiomyocyte hypertrophy in response to either alpha- or beta-adrenergic stimulation. Because an association between the Na+/H+ exchanger and cellular growth has been proposed, this study aimed to analyze the possible role of the antiporter in ...

We investigated the effects of adenosine and isoproterenol on enzymatically dispersed ventricular myocytes from bovine and guinea pig hearts. Intracellular stimulation of relaxed myocytes with regular striation patterns and normal resting potential resulted in action potentials with full plateaus accompanied by contractions. Adenosine in concentrations up to 0.2 mM had no significant effect on ...

The hemodynamic effects of isoproterenol infusion, 0.5 mug/kg per min were evaluated in eight intact anesthetized dogs during cardiac tamponade. During tamponade, the mean of pericardial pressures was increased from - 1.5 to 12.5 mm Hg, and the mean of right atrial pressures was increased from 1 to 12.4 mm Hg. Mean cardiac output fell from 144.8 to 44.8 ml/kg per min (P < 0.001), and rose to 10...

BACKGROUND The mechanism of enhanced vascular reactivity in young blacks, which may play a part in the development of hypertension, has not been defined. To determine the contribution of blunted vasodilatation mediated by beta 2-adrenergic receptors to this phenomenon, we compared forearm blood-flow responses to isoproterenol in young black and white normotensive men. METHODS We used venous-o...