Low birth weight in response to salt restriction during pregnancy is not due to alterations in uterine-placental blood flow or the placental and peripheral renin-angiotensin system

Low birth weight in response to salt restriction during pregnancy is not due to alterations in uterine-placental blood flow or the placental and peripheral renin-angiotensin system

Autor Leandro, Sandra Marcia Google Scholar
Shinohara Furukawa, Luzia Naoko Google Scholar
Massola Shimizu, Maria Heloisa Google Scholar
Casarini, Dulce Elena Autor UNIFESP Google Scholar
Seguro, Antonio Carlos Google Scholar
Patriarca, Giuliana Google Scholar
Coelho, Michella Soares Google Scholar
Dolnikoff, Miriam Sterman Autor UNIFESP Google Scholar
Heimann, Joel Claudio Google Scholar
Instituição Universidade de São Paulo (USP)
Universidade Federal de São Paulo (UNIFESP)
Resumo A number of studies conducted in humans and in animals have observed that events occurring early in life are associated with the development of diseases in adulthood. Salt overload and restriction during pregnancy and lactation are responsible for functional (hemodynamic and hormonal) and structural alterations in adult offspring. Our group observed that lower birth weight and insulin resistance in adulthood is associated with salt restriction during pregnancy On the other hand, perinatal salt overload is associated with higher blood pressure and higher renal angiotensin II content in adult offspring. Therefore, we hypothesised that renin-angiotensin system (RAS) function is altered by changes in sodium intake during pregnancy. Such changes may influence fetoplacental blood flow and thereby fetal nutrient supply, with effects on growth in utero and, consequently, on birth weight. Female Wistar rats were fed low-salt (LS), normal-salt (NS), or high-salt (HS) diet, starting before conception and continuing until day 19 of pregnancy, Blood pressure, heart rate, fetuses and dams' body weight, placentae weight and litter size were measured on day 19 of pregnancy. Cardiac output, uterine and placental blood flow were also determined on day 19. Expressions of renin-angiotensin system components and of the TNF-alpha gene were evaluated in the placentae. Plasma renin activity (PRA) and plasma and tissue angiotensin-converting enzyme (ACE) activity, as well as plasma and placental levels of angiotensins I, II, and 1-7 were measured. Body weight and kidney mass were greater in HS than in NS and LS dams. Food intake did not differ among the maternal groups. Placental weight was lower in LS dams than in NS and HS dams. Fetal weight was lower in the US group than in the NS and HS groups. the PRA was greater in IS dams than in NS and HS dams, although ACE activity (serum, cardiac, renal, and placental) was unaffected by the level of sodium intake. Placental levels of angiotensins I and II were lower in the HS group than in the ISIS and IS groups. Placental angiotensin receptor type 1 (AT(1)) gene expression and levels of thiobarbituric acid reactive substances (TBARS) were higher in HS dams, as were uterine blood flow and cardiac output. the degree of salt intake did not influence plasma sodium, potassium or creatinine. Although fractional sodium excretion was higher in HS dams than in NS and LS dams, fractional potassium excretion was unchanged. in conclusion, findings from this study indicate that the reduction in fetal weight in response to salt restriction during pregnancy does not involve alterations in uterine-placental perfusion or the RAS. Moreover, no change in fetal weight is observed in response to salt overload during pregnancy. However, salt overload did lead to an increase in placental weight and uterine blood flow associated with alterations in maternal plasma and placental RAS. Therefore, these findings indicate that changes in salt intake during pregnancy lead to alterations in uterine-placental perfusion and fetal growth. (C) 2008 Elsevier Inc. All rights reserved.
Palavra-chave salt
perinatal period
placenta
renin-angiotensin system
Idioma Inglês
Financiador Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Número do financiamento FAPESP: 04/06935-2
Data de publicação 2008-09-03
Publicado em Physiology & Behavior. Oxford: Pergamon-Elsevier B.V., v. 95, n. 1-2, p. 145-151, 2008.
ISSN 0031-9384 (Sherpa/Romeo, fator de impacto)
Publicador Elsevier B.V.
Extensão 145-151
Fonte http://dx.doi.org/10.1016/j.physbeh.2008.05.011
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:000259536100023
Endereço permanente http://repositorio.unifesp.br/handle/11600/30901

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