Effects of pre- and postnatal protein deprivation and postnatal refeeding on atrial natriuretic peptide (ANP) granules of auricular cardiocytes

SummaryBackground & aimsAtrial natriuretic peptide (ANP-granules) of auricular cardiocytes was examined by morphometry in undernourished and refed rats.MethodsThe study was conducted on 21 and 42-day-old rats from mothers exposed to 73% protein restriction during the gestation and lactation with and without refeeding and on age-matched control animals. The body and the heart were weighted and the ANP-granules are located by transmission electron microscopy.ResultsProtein deprivation in the 42 postnatal days reduced the body weights and the heart weights of the pups. Refeeding did not restore body weight or heart weight to control. In the undernourished group, the number of ANP-granules/field (27.3 ± 6.22) was significantly (p < 0.05) greater at 42 days than in the control (10.5 ± 1.89). In the refed group, the number of ANP-granules was also significantly greater, than that in the group on undernutrition. The diameter of ANP-granules in the undernourished animals was similar to the refed rats at 42 days and significantly greater than in the control (p < 0.05).ConclusionRefeeding between 21 and 42 days increased the number of ANP-granules and maintained their diameter even when there is a reduction in heart weight caused by protein deprivation.