Unreliability of lithium clearance as a marker of proximal tubular function during haemorrhagic hypotension in the rat.
Fractional lithium excretion (FELi) was measured before and after hypotensive haemorrhage (15 ml (kg body wt)-1) in anaesthetized Brattleboro rats; simultaneously, micropuncture collections were made from late proximal convoluted tubules. Micropuncture data indicated that fractional reabsorption in the proximal convoluted tubules was not affected significantly by haemorrhage, whereas FELi fell from 0.25 +/- 0.02 (mean +/- S.E.M.; control period) to 0.03 +/- 0.01. In time-control animals, no significant change in either variable was observed. These results suggest that lithium clearance is an unreliable marker of proximal tubular function during haemorrhagic hypotension.
Walter
S J
SJ
Department of Physiology, Charing Cross & Westminster Medical School, London.
Shirley
D G
DG
D000818:Animals; D006470:Hemorrhage / Q000503:physiopathology*; D007022:Hypotension / Q000503:physiopathology*; D007444:Inulin / Q000097:blood / Q000652:urine; D007687:Kidney Tubules, Proximal / Q000378:metabolism / Q000503:physiopathology*; D008094:Lithium; D008297:Male; D051381:Rats; D011910:Rats, Brattleboro
D007444:Inulin; D008094:Lithium