Numerous studies have suggested that epinephrine may facilitate neural release of NE. There have been no studies in humans that demonstrate the functional significance of this action. To determine whether epinephrine facilitates neurogenic vasoconstriction in humans, we contrasted forearm vasoconstrictor responses to a reflex stimulus (lower body negative pressure [LBNP]) and to intraarterial N...

We hypothesized that beta-adrenergic stimulation with isoproterenol during continuous normothermic cardioplegic arrest would enhance the regenerative and regulatory function of the myocardium, resulting in improved cardiac function. We studied isolated rabbit hearts paced at approximately 200 beats per minute (bpm) and perfused by a support rabbit. We measured ventricular pressure over a range ...

The early effects (0-120 s) of the @-adrenergic secretagogue isoproterenol (2 lo-‘ M) and the muscarinic secretagogue carbamoylcholine (2lo-’ M) on various parameters of lipid and phospholipid metabolism were studied in isolated guinea pig parotid acinar cells. Both agonists enhanced within 10-20 s the incorporation of radioactive palmitate into the diacylglycerol, the triglyceride, and the pho...

background: despite the emerging evidence on beneficial effects of probiotics on the cardiovascular system, their impact on the management of ischemic heart diseases and its possible mechanism have not been elucidated. methods: four viable probiotics bacterial strains, including bifidobacterium breve, lactobacillus casei, lactobacillus bulgaricus and lactobacillus acidophilus, at the concentrat...

We tested mongrel dogs by intradermal injection and tracheobronchial aerosol challenge with Ascaris suum antigen extract. All dogs were skin-test positive but could be segregated, on the basis of airways resistance measurements, into "asthmatic" (bronchoreactive) and "nonasthmatic" (nonbronchoreactive) groups. By using tracheal rings from these dogs, we measured the abilities of the beta-adrene...

This study assessed the effects of exogenous isoproterenol on the proliferation of the proximal tubular cell lines MCT and LLC-PK1. Both cell lines express beta-adrenergic receptors as demonstrated by Scatchard analysis of binding data, receptor-cross linking studies, and mRNA expression for beta 2-adrenergic receptors. Isoproterenol (10(-7) M) for 15 min stimulated the formation of intracellul...

The present study was designed to evaluate the cardioprotective effects of Lagenaria siceraria fruit juice in isoproterenol-induced myocardial infarction. Rats injected with isoproterenol (200 mg/kg, s.c.) showed a significant increase in the levels of serum uric acid, tissue Na(++) and Ca(++) ions and membrane-bound Ca(+2)-ATPase activity. A significant decrease in the levels of serum protein,...

BACKGROUND Tilt testing is used to establish the diagnosis of neurally mediated syncope. However, applicability of the tilt test is limited by test sensitivity and length of time required to perform the test. We hypothesized that adenosine could facilitate the induction of neurally mediated syncope through its sympathomimetic effects and therefore could be used as an alternative to routine tilt...

To assess the possible contribution of the circulatory and cardiac renin-angiotensin system (RAS) to the cardiac hypertrophy induced by a beta-agonist, the present study evaluated the effects of isoproterenol, alone or combined with an angiotensin I-converting enzyme inhibitor or AT(1) receptor blocker, on plasma and LV renin activity, ANG I, and ANG II, as well as left ventricular (LV) and rig...

In a previous study, we showed that isoproterenol induced actin depolymerization in human airway smooth muscle cells by both protein kinase A (PKA)-dependent and -independent signaling pathways. We now investigate the signaling pathway of PKA-independent actin depolymerization induced by isoproterenol in these cells. Cells were briefly exposed to isoproterenol or PGE(1) in the presence and abse...