BACKGROUND Extracellular signal-regulated kinases (ERKs) and calcineurin have been reported to play important roles in the development of cardiac hypertrophy. We examined here the relation between calcineurin and ERKs in cardiomyocytes. METHODS AND RESULTS Isoproterenol activated ERKs in cultured cardiomyocytes of neonatal rats, and the activation was abolished by chelation of extracellular C...

The effect of beta-adrenoceptor activation on levcromakalim-induced relaxation was investigated in myograph-mounted rat mesenteric arteries. The nonselective beta-adrenoceptor agonist isoproterenol (at a concentration causing approximately 30% relaxation of methoxamine-induced tone) potentiated relaxation to levcromakalim; higher concentrations exerted no additional effect. The modulatory and r...

The present study was conducted to elucidate the antioxidant role of an ayurvedic formulation Abana in isoproterenol induced myocardial infarction in rats. In myocardial necrosis induced by isoproterenol, a significant increase in serum iron content with a significant decrease in plasma iron binding capacity, ceruloplasmin activity and glutathione level were observed. There was also a significa...

Dear Editor, the recent report on “Isoproterenol infusion in septic shock” is very interesting (1). Wiramus et al. concluded that “use of isoproterenol was associated with an increase of tissue oxygen saturation (1).” In fact, there are some issues of isoproterenol use to be discussed. First, the increased heart rate due to infusion is common (2). On the other hand, the occurrence of paradoxica...

Nitric oxide has been implicated in the inhibition of catecholamine-stimulated lipolysis in adipose tissue by as yet unknown mechanisms. In the present study, it is shown that the nitric oxide donor, 2,2-diethyl-1-nitroso-oxyhydrazine, antagonized isoproterenol (isoprenaline)-induced lipolysis in rat adipocytes, freshly isolated from white adipose tissue, by decreasing the potency of the beta-a...

The ability of the M2 muscarinic receptor to inhibit the relaxant effects of forskolin and isoproterenol was investigated in bovine trachea. In most experiments, we measured contractile responses to oxotremorine-M in smooth muscle isolated from bovine trachea in which a majority of M3 receptors were inactivated by treatment with N-(2-chloroethyl)-4-piperidinyl diphenylacetate. In the presence o...

Myocardial infarction (MI) is a common presentation of the ischemic heart disease. Lavandula angustifolia is a herbaceous plant with antioxidative effects.This study was designed to investigate the cardioprotective effects of lavandula angustifolia essential oil against isoproterenol-induced MI in rats.The dried sample was subjected to hydrodistillation by using a Clevenger and the oils were dr...

This study evaluated the chronotropic and inotropic responses to glucagon in spontaneously beating isolated right atria of rat heart. For comparison, we also investigated the effects resulting from stimulating β-adrenoceptors with isoproterenol in this tissue. Isoproterenol increased both atrial frequency and contractility but glucagon only enhanced atrial rate. The transcript levels of glucago...

We examined whether adenosine equally attenuated the stimulatory effects of isoproterenol on arrhythmic activity and twitch shortening of guinea pig isolated ventricular myocytes. Transmembrane voltages and whole cell currents were recorded with patch electrodes, and cell twitch shortening was measured using a video-motion detector. Isoproterenol increased the action potential duration at 50% r...

EIK-NES, K. B. An effect of ~,roprotereno~ n rafes of synthesis and secretion of testosterone. Am. J. Physiol. 2 17(6) : 1764-I 770. 1969.When epinephrine, norepinephrine, ethylnorepinephrine, or isoproterenol was infused al a constant rate via the spermatic artery of the dog, the level of testosterone increased in spermatic venous blood. Of the catecholamines tried, isoproterenol was the stron...