Premium
Mechanisms of phosphate transport in sheep intestine and parotid gland: response to variation in dietary phosphate supply
Author(s) -
ShiraziBeechey SP,
Beechey RB,
Penny J,
Vayro S,
Buchan W,
Scott D
Publication year - 1991
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.1991.sp003489
Subject(s) - phosphate , brush border , enterocyte , symporter , epithelial polarity , parotid gland , small intestine , vesicle , apical membrane , cotransporter , chemistry , endocrinology , medicine , transporter , biology , biochemistry , membrane , sodium , pathology , organic chemistry , gene
The transport of phosphate in intestinal brush‐border membrane and parotid basolateral membrane vesicles isolated from sheep maintained on high and low phosphate diets have been studied. The mechanism of the transport of phosphate in the intestine is via a proton symporter whilst in the parotid gland it is effected by a Na+ coupled transporter. In sheep fed a low‐P diet there is no change in the capacity of the parotid basolateral membrane to transport phosphate into the parotid end piece cells. This is in marked contrast to the response of the enterocyte brush‐border membrane, where there is a significant enhancement of the capacity of the membrane to transport phosphate. We conclude that in sheep the gut appears to play a major role in response to phosphate deprivation, by increasing the capacity to transport phosphate. This enhancement is not achieved by increases in the levels of circulating 1,25‐dihydroxycholecalciferol.