The Behavior of Renal Blood Flow After Partial Constriction of the Renal Artery

Abstract

1. Studies have been made of the behavior of renal blood flow after partial constriction of the renal artery in twenty-four dogs. 2. When reduction in renal blood flow is produced by partial constriction of the renal artery, a readjustment of flow in the direction of normal occurs within a few minutes, subsequent constriction being again followed by a return of flow toward normal until the artery is markedly constricted. 3. Renal blood flow after marked constriction of the artery becomes extremely susceptible to the vasoconstrictive action of small doses of adrenalin, and flow may cease with larger doses for a considerable period of time. 4. Arterial hypertension of significant degree may follow partial constriction of one renal artery during brief experiments when adrenalin in addition has been administered. 5. Further evidence is presented in favor of the concept that the renal circulation enjoys a control independent of systemic arterial pressure.

Pressure-dependent contraction of rat juxtamedullary afferent arterioles.

“…These results are not consistent with previous conclusions from other authors or even from our own laboratory. Myogenic responses to increases in transmural pressure have been reported in isolated rabbit afferent arterioles, 16 interlobular arteries of the rat and dog, 8 - 23 and in transplanted renal arteries of hamsters. 9 Recently, Carmines et al 12 and Navar et al 13 reported myogenic pressure-dependent contractions of interlobular arteries in blood perfused juxtamedullary nephron preparation.…”

The Effect of Tyrosinase on Experimental Hypertension

“…Arterial hypertension can be produced in brief experiments by very small amounts of this hormone if one kidney is ischemic. Adrenalin in these amounts is a powerful renal vasoconstrictor in dogs (11). Destruction of adrenalin may allow renal vasodilatation.…”

“…The reaction of the blood flow to adrenalin by the ischemic kidney was reversed in two experiments, vasoconstriction being replaced by vasodilatation. Hypertension which had resulted from partial constriction of the renal artery and the injection of adrenalin (11) was abolished.…”

Effect of Epinephrine on the Renal Circulation

“…For example, Schroeder and Steele emphasized the lack of effect of epinephrine on the renal vascular bed (12). The roots of the contradictory data lie largely in the use of doses which are not comparable, although there may also be some variation depending on the type of animal studied.…”