title: Changes of cytosolic calcium and contractility of young rat vas deferens by acute treatment with amphetamine, fluoxetine or sibutramine.
abstract: Previous studies conducted in our laboratory indicated that administration of amphetamine, fluoxetine or sibutramine affects the sympathetic nervous system of the rat vas deferens. Therefore, our goal was to verify the role of calcium in vasa deferentia from young rats pretreated with a single dose of these drugs. Young 40-day-old male Wistar rats were pretreated with amphetamine 3 mg/kg, fluoxetine 10 mg/kg or sibutramine 6 mg/kg for 4 h before the experiments. CaCl(2) (10 mM) was used to induce contraction through time-effect curves in calcium-free solution to measure phasic and tonic components. We also evaluated the calcium-induced fluorescence of vas deferens cut into thin slices. In rats pretreated with amphetamine, we found an increase of the tonic contraction component which was reduced by verapamil. The phasic and tonic responses were increased in the group treated with fluoxetine, but only the tonic response was more sensitive to the antagonism by verapamil. The group treated with sibutramine showed an increase of phasic response whereas the tonic component was decreased. In this group an increase of the affinity for verapamil antagonism was found. In the calcium fluorescence study it was observed that the group treated with amphetamine, fluoxetine or sibutramine showed higher basal Ca(2+) fluorescence after stimulus with KCl (70 mM), noradrenaline (10(-4)M) or acetylcholine (10(-4)M). In all pretreated groups the calcium fluorescence was diminished by nifedipine 10(-7)M. Therefore, the pretreatment with amphetamine, fluoxetine or sibutramine seems to affect the calcium contractility and homeostasis in young rat vas deferens.
authors: Department of Pharmacology, Federal University of São Paulo-UNIFESP, Rua 3 de Maio 100, 04044-020 São Paulo, SP, Brazil.
authors: Neide Hyppolito
authors: NH
authors: Jurkiewicz
authors: Edilson Dantas
authors: ED
authors: da Silva Júnior
authors: Bruno Palmieri
authors: BP
authors: de Souza
authors: Luciana
authors: L
authors: Ferreira Verde
authors: Janaina
authors: J
authors: Drawanz Pereira
authors: Cairo
authors: C
authors: Mendes Sobrinho
authors: Soraya
authors: S
authors: Soubhi Smaili
authors: Afonso
authors: A
authors: Caricati-Neto
authors: Regiane
authors: R
authors: Miranda-Ferreira
authors: Aron
authors: A
authors: Jurkiewicz
mesh_terms: D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002491:Central Nervous System Agents / Q000494:pharmacology*; D003503:Cyclobutanes / Q000494:pharmacology; D003600:Cytosol / Q000187:drug effects* / Q000378:metabolism*; D005473:Fluoxetine / Q000494:pharmacology; D006706:Homeostasis / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014649:Vas Deferens / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*
chemical_list: D002491:Central Nervous System Agents; D003503:Cyclobutanes; D005473:Fluoxetine; D000661:Amphetamine; D002118:Calcium; C058254:sibutramine