Abstract
Differences in dietary protein level induce differences in fractional excretion of urea, in arginine vasopressin (AVP) plasma level, and in urine concentrating activity (in which intervene the renal urea transporters (UT)). The abundance of mRNA for UT-A1 (of the inner medullary collecting duct, IMCD) UT-A2 (of the descending thin limb) and UT-B1 (of descending vasa recta) was determined by Northern analysis of total RNA extracted from medullary subregions of Sprague-Dawley rats fed for 1 week, a low, normal, or high protein diet. The implication of AVP was then examined by studying AVP- deprived (Brattleboro) rats. Our results show that none of these transporters is affected by the level of protein intake, except UT-A1 that is reduced in terminal IMCD by low protein diet in the absence of AVP (Brattleboro rats). These data suggest that (1) the previously reported effect of kidney medulla hypertonicity on UT-A2 and UT-B1 mRNA expression is somehow obliterated by protein intake deficiency or excess, and (2) AVP influences the mRNA abundance of the UT-A1 of the terminal IMCD during protein deficiency.
Original language | English (US) |
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Pages (from-to) | 44-51 |
Number of pages | 8 |
Journal | Experimental Nephrology |
Volume | 7 |
Issue number | 1 |
DOIs | |
State | Published - 1999 |
Keywords
- Arginine vasopressin
- Brattleboro rats
- Dietary protein
- Kidney
- Messenger RNA
- Urea excretion
- Urea transporters
- Urine concentrating activity
ASJC Scopus subject areas
- Nephrology