Intestinal calcium transport in the spontaneously hypertensive rat

Alterations in intestinal transport and absorption of calcium have been described for the spontaneously hypertensive rat (SHR) as compared to the normotensive Wistar-Kyoto rat (WKY). Several in vitro studies of intestinal calcium transport done with everted gut sacs and the Ussing chamber found that calcium transport was lower in the SHR than the WKY. Calcium uptake by isolated enterocytes was also lower in SHR than WKY. However, net intestinal calcium absorption measurements by the balance method are variable in the literature with findings of decreased, increased, and no difference in absorption reported for the SHR. Study differences in age of the animals and diets may explain some of the disparate findings. The possible relationship between systemic alterations in calcium metabolism, including intestinal transport and absorption, and the pathogenesis of hypertension is discussed.