Time-dependent up-regulation of Ca(2+) channels in vas deferens of newborn rats fed with breast milk of mothers under treatment with nifedipine

Time-dependent up-regulation of Ca(2+) channels in vas deferens of newborn rats fed with breast milk of mothers under treatment with nifedipine

Author Valera, Adriana Gonzalez Autor UNIFESP Google Scholar
Verde, Luciana Ferreira Autor UNIFESP Google Scholar
Lopes Lafayette, Simone Sette Autor UNIFESP Google Scholar
Verreschi, Ieda T. Autor UNIFESP Google Scholar
Caricati-Neto, Afonso Autor UNIFESP Google Scholar
Jurkiewicz, Aron Autor UNIFESP Google Scholar
Jurkiewicz, Neide Hyppolito Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Universidade Federal de Pernambuco (UFPE)
Abstract Our aim was to check for calcium channel maturation and regulation on newborn rats during breastfeeding by mothers treated with the L-type calcium channel blocker nifedipine. Contractions by KCl and radioligand binding techniques were used to verify if Call Channels are modified in rat vas deferens of 40-day old litters that were breastfed by mothers injected daily with nifedipine during nursery. Injections were applied in the beginning (1st until 8th day), middle (9th until 16th day), or end (17th until 24th day) of nursery, to verify the period of highest susceptibility of newborn to nifedipine receptor regulation. Contractile responses revealed that only after the middle period of treatment of mothers the maximal effects (E(max)) induced in pups by KCl were increased by about 35%, without changes of apparent affinity (pD(2)). Additionally, binding studies with [(3)H] Isradipine in cell membrane preparations showed a greater density (B(max)) of Ca(2+) channels by about 55%, without changes of affinity (K(d)). Changes were not detected after treatment of mothers in the beginning or end of breastfeeding. in addition, in vas deferens of 60-day old litters, the E(max) returned to control values, showing that changes were not persistent. Moreover, body and vas deferens weights and blood testosterone of newborn were never changed. the histology of mammary gland was similar for treated and control mothers, suggesting a stable milk production. It is concluded that nifedipine treatment of mothers, if made during the 9th to 16th day of lactation, produced a short lasting reversible up-regulation of L-type Ca(2+) channels. (C) 2008 Published by Elsevier B.V.
Keywords Breastfeeding
Nifedipine
Calcium channel
Smooth muscle
Vas deferens
Newborn rat
Language English
Sponsor Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Date 2008-12-03
Published in European Journal of Pharmacology. Amsterdam: Elsevier B.V., v. 599, n. 1-3, p. 131-136, 2008.
ISSN 0014-2999 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 131-136
Origin http://dx.doi.org/10.1016/j.ejphar.2008.09.022
Access rights Closed access
Type Article
Web of Science ID WOS:000261157500021
URI http://repositorio.unifesp.br/handle/11600/31096

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