Fatemeh Sabet Sarvestani - Graduated from School of Veterinary Medicine, Shiraz University, Shiraz, Iran
Farhad Rahmanifar - Department of Basic Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
Amin Tamadon - Transgenic Technology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran

Food intake of rats increases during pregnancy. This requires changes in the structure of the small intestine to absorb additional food. The aim of the present study was to investigate the morphological changes in the layers of small intestine in rats during pregnancy. Duodenum, jejunum and ileum of ۱۸ pregnant Sprague-Dawley rats (day ۷, ۱۴ and ۲۱ of pregnancy) were collected. Villous height and width and thickness of lamina propria, tunica muscularis entirely and separately (circular and longitudinal layers) were measured on transverse sections. During pregnancy increasing villi length and muscular layer thickness was observed in duodenum. Furthermore, along with the progress of gestation greatest histomorphometric change in small intestine was observed in the jejunum. The reduction in the ileum histomorphologic indices was observed during pregnancy. In conclusion, increase in histomorphologic indices of duodenum and jejunum supplies more capacity of duodenum to digest food intake during pregnancy and decrease in these indices in ileum controls the absorption of excess produced amino acids and glucose by hyperphagia.

Histomorphometry, Pregnancy, Rat, Small Intestine