title: Influence of acute treatment with sibutramine on the sympathetic neurotransmission of the young rat vas deferens.
abstract: The effects of acute treatment with sibutramine on the peripheral sympathetic neurotransmission in vas deferens of young rats were still not evaluated. Therefore, we carried out this study in order to verify the effects of acute sibutramine treatment on the neuronal- and exogenous agonist-induced contractions of the young rat vas deferens. Young 45-day-old male Wistar rats were pretreated with sibutramine 6 mg/kg and after 4h the vas deferens was used for experiment. The acute treatment with sibutramine was able to increase the potency (pD2) of noradrenaline and phenylephrine. Moreover, the efficacy (Emax) of noradrenaline was increased while the efficacy of serotonin and nicotine were decreased. The maximum effect induced by a single concentration of tyramine was diminished in the vas deferens from treated group. Moreover, the leftward shift of the noradrenaline curves promoted by uptake blockers (cocaine and corticosterone) and β-adrenoceptor antagonist (propranolol) was reduced in the vas deferens of treated group. The initial phasic and secondary tonic components of the neuronal-evoked contractions of vas deferens from treated group at the frequencies of 2 Hz were decreased. Moreover, only the initial phasic component at 5 Hz was diminished by the acute treatment with sibutramine. In conclusion, we showed that the acute treatment with sibutramine in young rats was able to affect the peripheral sympathetic nervous system by inhibition of noradrenaline uptake and reduction of the neuronal content of this neurotransmitter, leading to an enhancement of vas deferens sensitivity to noradrenaline.
authors.affiliation: Department of Pharmacology, Universidade Federal de São Paulo - UNIFESP, Rua 3 de Maio 100, 04044-020 São Paulo-SP, Brazil.
authors.forename: Bruno Palmieri
authors.initials: BP
authors.lastname: de Souza
authors.affiliation: Department of Pharmacology, Universidade Federal de São Paulo - UNIFESP, Rua 3 de Maio 100, 04044-020 São Paulo-SP, Brazil.
authors.forename: Edilson Dantas
authors.initials: ED
authors.lastname: da Silva
authors.affiliation: Department of Pharmacology, Universidade Federal de São Paulo - UNIFESP, Rua 3 de Maio 100, 04044-020 São Paulo-SP, Brazil. Electronic address: aron.farm@epm.br.
authors.forename: Aron
authors.initials: A
authors.lastname: Jurkiewicz
authors.affiliation: Department of Pharmacology, Universidade Federal de São Paulo - UNIFESP, Rua 3 de Maio 100, 04044-020 São Paulo-SP, Brazil.
authors.forename: Neide Hyppolito
authors.initials: NH
authors.lastname: Jurkiewicz
mesh_terms: D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D003503:Cyclobutanes / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009474:Neurons / Q000166:cytology / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013564:Sympathetic Nervous System / Q000166:cytology* / Q000187:drug effects* / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects*; D014649:Vas Deferens / Q000187:drug effects* / Q000502:physiology
chemical_list: D018759:Adrenergic Uptake Inhibitors; D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D003503:Cyclobutanes; C058254:sibutramine
keywords: Acute treatment; Sibutramine; Sympathetic neurotransmission; Vas deferens; Young rats