The purpose of our study was to investigate the inotropic response to the endogenous agonist norepinephrine mediated through alpha-1 adrenoceptors and to compare this response to that mediated through beta-adrenoceptors in failing human ventricular myocardium. We studied ex vivo the inotropic effect of norepinephrine in isometrically contracting trabecular myocardium from both ventricles of exp...

Receptor activation results in homologous regulation and can also affect other types of receptors (a process that has been reported to heterologous regulation). Heart cells express subtypes of muscarinic receptors and adrenoceptors, almost antagonistic in their action (M2 muscarinic receptors and beta1-adrenoceptors). Therefore, they provide an excellent model of heterologous regulation. Moreov...

The aim of the present study was to investigate if there is an altered expression of alpha-adrenoceptors during organ culture of rat mesenteric artery segments by using a sensitive pharmacological method and molecular biological techniques. Noradrenalin (NA) induced contraction via alpha1-adrenoceptors. The contraction and alpha1A-adrenoceptor mRNA levels were elevated during organ culture. Tra...

Heat-shock protein concentrations in the blood increase after exposure to a variety of stressors, including trauma and psychological stress. Although the physiological function of extracellular heat shock protein remains controversial, there is evidence that extracellular heat shock protein 72 (Hsp72) can facilitate immunologic responses. The signal(s) that mediate(s) the in vivo elevation of e...

Extensive evidence indicates that norepinephrine modulates memory storage through an activation of beta-adrenoceptors in the basolateral nucleus of the amygdala (BLA). Recent findings suggest that the effects of beta-adrenergic activation on memory storage are influenced by alpha1-adrenoceptor stimulation. Pharmacological findings indicate that activation of postsynaptic alpha1-adrenoceptors po...

The ovarian hormones estradiol (E(2)) and progesterone (P) facilitate rat lordosis behavior in part by regulating the expression of and signal transduction by adrenoceptors in the hypothalamus (HYP) and preoptic area (POA). The major adrenoceptor subtype mediating E(2) and P facilitation of lordosis is the alpha(1)-adrenoceptor. In the present studies, we tested the hypotheses that (1) alpha(1)...

Background—Contrary to b1and b2-adrenoceptors, b3-adrenoceptors mediate a negative inotropic effect in human ventricular muscle. To assess their functional role in heart failure, our purpose was to compare the expression and contractile effect of b3-adrenoceptors in nonfailing and failing human hearts. Methods and Results—We analyzed left ventricular samples from 29 failing (16 ischemic and 13 ...

Previous work has shown that the genes encoding each alpha1-adrenoceptor subtype are coexpressed throughout the peripheral vascular system. We have evaluated subtype-selective antibodies as tools to determine the extent of protein expression in arteries. The alpha1A-, alpha1B-, and alpha1D-adrenoceptors were detected in the medial layer of the aorta, caudal, femoral, iliac, renal, superior mese...

Honda, Eiko, Kentaro Ono, Shinji Kataoka, and Kiyotoshi Inenaga. Activation of subfornical organ neurons in rats through preand postsynaptic -adrenoceptors. Am J Physiol Regul Integr Comp Physiol 290: R1646–R1653, 2006. First published February 2, 2006; doi:10.1152/ajpregu.00801.2004.—The effects of noradrenaline (NA) and its analogs on subfornical organ (SFO) neurons in rat slice preparations ...

Recently, intracavernous injection of some vasoactive drugs has been performed for the diagnosis and treatment of impotence. Despite extensive studies the mechanism of erection is still obscure. Therefore, the author studied the effects of some vasoactive drugs on isolated rabbit corpus cavernosum penis. Norepinephrine, phenylephrine or clonidine caused contraction of isolated rabbit corpus cav...