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Renal tubular flow dynamics during angiotensin diuresis in the rat
Author(s) -
FINBERG J. P. M.,
PEART W. S.
Publication year - 1970
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1970.tb12899.x
Subject(s) - diuresis , renin–angiotensin system , angiotensin ii , endocrinology , medicine , natriuresis , kidney , chemistry , blood pressure
Summary1 Tubular size and lissamine green transit times were measured in rat kidneys undergoing a diuretic response to angiotensin II (05 μg/kg per min), and compared with the changes observed during diuresis induced by osmotic diuretics, noradrenaline and chlorothiazide. 2 Angiotensin always caused a marked prolongation in proximal and distal tubular transit times; individual distal convolutions were coloured for prolonged periods, and lissamine green appeared in high concentration in distal tubules. 3 Marked changes were observed in superficial tubular calibre during a stable diuretic response to angiotensin. Where distal tubular diameter was normal for the rate of urine flow, proximal tubular volume was generally reduced. In a number of experiments, however, distal tubules were markedly dilated, and in these cases proximal tubular volume was also often increased. Angiotensin may therefore be capable of causing a degree of internal hydronephrosis in the rat kidney. 4 Prolongation of dye transit times, and the appearance of a concentrated lissamine green bolus in distal tubules, was suggestive of a decreased superficial nephron flow rate, indicating that the diuretic effect of angiotensin may take place only through deeper nephrons.