Journal of Morphological Sciences
http://www.jms.periodikos.com.br/article/587cb4477f8c9d0d058b45a7
Journal of Morphological Sciences
Original Article

MORPHOMETRIC ALTERATIONS IN HEPATOCYTES AND ULTRASTRUCTURAL DISTRIBUTION OF LIVER GLYCOGEN IN PACU (Piaractus mesopotamicus HOLMBERG, 1887) DURING FOOD RESTRICTION AND REFEEDING

Valéria Leão Souza; Laurelúcia Orives Lunardi; Lúcia Helena Vasques; Luciana Casaletti; Laura Satiko Okada Nakaghi; Elisabeth Criscuolo Urbinati

Downloads: 0
Views: 380

Abstract

The morphometric alterations in hepatocytes and the ultrastructural distribution of tissue glycogen in pacu (Piaractus mesopotamicus) were studied following food restriction and refeeding. Fish (200-300 g) were allocated to control and experimental groups. The experimental group was sampled after 0, 2, 7, 30 and 60 days of food restriction and after 7 and 30 days of refeeding. The control group, which was fed daily, was sampled on the same days. The morphometric results were analyzed by ANOVA in a 2x7 (feeding x days) factorial design and the averages compared by the Tukey test. Transmission electron microscopy showed liver glycogen mobilization during food restriction. The levels of glycogen did not return to normal after up to 30 days of refeeding. There was a decrease in the cytoplasmic area and volume after seven days without food whereas changes in the nuclear area and volume appeared after two days of food restriction. Recovery of the nuclear and cytoplasmic area and volume occurred after 7 days and 30 days of refeeding, respectively. These results indicate that liver glycogen supplies at least part of the energy requirement during food restriction in juvenile pacu. Thirty days of refeeding were not enough to re-establish the pre-restriction carbohydrate levels, probably because of the extra energy demand associated with the high metabolic rate that occurred during the compensatory process of refeeding at elevated ambient temperatures. However, the recovery seen in the morphometric parameters of the hepatocytes indicated a functional re-adjustment of the liver stimulated by the restored food supply.

Keywords

Fish, food restriction, glycogen, hepatocyte, refeeding
587cb4477f8c9d0d058b45a7 jms Articles
Links & Downloads

J. Morphol. Sci.

Share this page
Page Sections