RT Journal Article SR Electronic T1 URINE FORMATION BY THE PERFUSED KIDNEY: PRELIMINARY EXPERIMENTS ON THE ACTION OF CAFFEINE JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 485 OP 509 VO 7 IS 4 A1 A. N. RICHARDS A1 O. H. PLANT YR 1915 UL http://jpet.aspetjournals.org/content/7/4/485.abstract AB 1. A method is described for perfusing the rabbit's kidney in situ with hirudinized blood under conditions which permit adjustment and measurement of blood flow through the kidney. 2. When blood flow through the perfused kidney amounts to 28-30 cc. per minute, fluid is eliminated from the ureter which is comparable in composition with that secreted before perfusion was begun. 3. Rate of urine secretion by the perfused kidney is relatively constant when blood flow through the kidney is constant: it appears to be independent of changes of pressure in the renal circulation, provided (as in these experiments) changes in pressure do not cause changes in volume of blood flowing through it. 4. Caffeine causes diuresis in the perfused kidney when the rate of blood flow through the kidney remains constant. The increase in blood flow which occurs in the intact animal as the result of the action of caffeine upon the renal vessels is therefore not an essential factor in caffeine diuresis. 5. It is questionable whether 0.9 per cent sodium chloride (5-6 cc. per kilo) is capable of causing diuresis when blood flow through the kidney is constant: the same amount of sodium chloride, given as 5 per cent solution, is diuretic, even when the rate of kidney perfusion does not change. 6. Phlorhizin causes both diuresis and glucosuria in the perfused kidney.