André Sampaio Pupo

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BACKGROUND The C-terminal four amino acids (GEEV) of human alpha1A-adrenergic receptors (ARs) have been reported to interact with the PDZ domain of neuronal nitric oxide synthase (nNOS) in a yeast two-hybrid system. The other two alpha1-AR subtypes have no sequence homology in this region, raising the possibility of subtype-specific protein-protein(More)
G protein-coupled receptors (GPCRs) are the most important targets for drug discovery and not surprisingly ∼40% of all drugs currently in the market act on these receptors. Currently, one of the most active areas in GPCRs signaling is biased agonism, a phenomenon that occurs when a given ligand is able to preferentially activate one (or some) of the(More)
INTRODUCTION Premature ejaculation is one of the most common male sexual dysfunctions. Current pharmacological treatments involve reduction in penile sensitivity by local anesthetics or increase of ejaculatory threshold by selective serotonin reuptake inhibitors. α1-Adrenoceptors (α1-ARs) and L-type calcium channels are expressed in the smooth muscles of(More)
We investigated whether or not surgical denervation of the rat vas deferens changes the alpha(1)-adrenoceptor subtypes involved in the contractions to noradrenaline. Denervated vas deferens was approximately 22 times more sensitive to noradrenaline (pD(2)=7.35+/-0.04) than control vas (pD(2)=6.01+/-0.03). This difference in noradrenaline potency was(More)
1. The actions of the alpha1-adrenoceptor antagonist indoramin have been examined against the contractions induced by noradrenaline in the rat vas deferens and aorta taking into account a putative neuronal uptake blocking activity of this antagonist which could result in self-cancelling actions. 2. Indoramin behaved as a simple competitive antagonist of the(More)
AIMS Aging is highly associated with benign prostate hyperplasia (BPH). We investigated here the alterations of the contractile and relaxant machinery in prostates of middle-aged rats, focusing on the Rho-kinase, nitric oxide (NO)-soluble guanylyl cyclase (sGC), α1- and β-adrenoceptor pathways. METHODS Male Wistar young (3.5-month old) and middle-aged(More)
G protein-coupled receptors are sensors that interact with a large variety of elements, including photons, ions, and large proteins. Not surprisingly, these receptors participate in the numerous normal physiologic processes that we refer to as health and in its perturbations that constitute disease. It has been estimated that a large percentage of drugs(More)
The objective of this study was to evaluate the pharmacological mechanisms involved in anti-inflammatory and antidiarrheal actions of hydroalcoholic extract obtained from the leaves of Cissus sicyoides (HECS). The anti-inflammatory effect was evaluated by oral administration of HECS against acute model of edema induced by xylene, and the mechanisms of(More)
Imipramine is a tricyclic antidepressant inhibitor of norepinephrine and serotonin neuronal reuptake. The roles of specific α1-adrenoceptor subtypes that might be targeted by the increased synaptic levels of noradrenaline induced by imipramine are not well understood. This study investigates the α1-adrenoceptor subtypes involved in the anti-immobility(More)
Sperm acquire motility and fertility capacity during epididymal transit, under the control of androgens and sympathetic innervations. It is already known that the acceleration of epididymal sperm transit time can lead to lower sperm quality. In a previous work we showed that rats exposed to the anorexigen sibutramine, a non-selective(More)