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Intrarenal Haemodynamics in Rats during Haemorrhagic Hypotension *
Author(s) -
Sandoz P.,
Grandchamp A.,
Truniger B.
Publication year - 1974
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1111/j.1365-2362.1974.tb02339.x
Subject(s) - hemodynamics , renal blood flow , blood flow , kidney , renal circulation , perfusion , chemistry , vascular resistance , medicine , endocrinology
. Previous studies of intrarenal haemodynamics by wash‐out with inert gas suggested that haemorrhagic hypotension (HH) in the dog causes a redistribution of intrarenal blood flow with a patchy cortical hypoperfusion, mainly due to an increased concentration of circulating catecholamines. In the present experiments intrarenal haemodynamics were studied by the same methods in the rat during prolonged HH with a mean arterial BP of 51 mm Hg. Under these conditions inert gas wash‐out studies showed a decrease in compartment I (CP I) flow fraction (“cortical flow fraction”) from 81.5% to 43.2% of total renal blood flow (RBF). CP I blood flow dropped from 3.13 ml/min. to 0.63 ml/min. per g kidney weight. Total renal vascular resistance increased by a factor of 1.2 as compared with control conditions. These changes in intrarenal haemodynamics were considerably smaller than those observed in the dog under comparable conditions. In contrast to observations in the canine kidney no patchy areas of cortical hypoperfusion occurred in the rat, and there was no evidence of stratification of cortical blood flow during HH. Instead, there was an even reduction in cortical blood flow from the subcapsular area to the cortico‐medullary border as indicated by inert gas wash‐out studies and 85 krypton autoradiographs. The meaning and pathogenesis of the observed differences between both species remains to be defined. It is suggested that in the rat the reaction of the renal vasculature to sympathoadrenal stimuli and/or to angiotensin might be different from that in the dog.