The Effects of Renal Hypertension on the Vessels of the Ears of Rabbits

Abell, Richard G.; Page, Irvine H.

doi:10.1084/jem.75.6.673

Cited by 13 publications

(3 citation statements)

References 5 publications

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“…Also the walls of these vessels were seen to be thickened during the period of constriction. That such thickening occurs when arterioles constrict has been shown previously by Clark,Clark,and Williams (20), by Clark and Clark (21,22), and by Abell and Page (23).…”

Section: Discussionsupporting

confidence: 66%

The State of the Vessels of the Mesentery in Shock Produced by Constricting the Limbs and the Behavior of the Vessels Following Hemorrhage

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Abell

1943

Journal of Experimental Medicine

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Contemporary evidence has left unanswered the question as to whether or not during shock the small vessels are constricted or dilated. That is not to say that the subject has not been extensively investigated. But it has remained a vexed problem, perhaps because the methods employed for demonstrating caliber changes in vessels have usually been indirect ones and often highly unphysiological.Not only is there disagreement as to whether arteriolar constriction occurs in shock, but also as to whether such constriction, if it does occur, is of sufficient intensity to play an important part in the mechanism of shock.The clinical observation that during shock patients exhibit extreme pallor has usually been cited as evidence indicating vasoconstriction. Not only is the skin pale and cold but incision into it is almost bloodless. We have inspected the eyegrounds of such patients and found the arterioles markedly constricted. This is at least suggestive that arteriolar constriction is generalized if the analogy holds for shock as it does in hypertension. Both in animals (1, 2) and man (3) blood flow to the periphery decreases conspicuously during shock. This has been demonstrated by the finding of decreased cutaneous venous oxygen and increased arterio-venous oxygen difference (4--6), as well as by other methods.According to the work of Seelig and Lyon (7) vascular tone in shock seems to be maintained to some degree by nervous impulses, for severance of the sciatic nerve, when shock had occurred, resulted in marked increase in venous blood flow. Proportionately there was a greater increase in flow in shocked than in normal animals, suggesting vasoconstriction in the former. These measurements were only approximate, however, and Bartlett (8) believed he could show from calculation that if vasomotor tone had been markedly increased the change in outflow after section of the sciatic nerve should have been greater than it was. He injected salt solution under constant pressure into medium sized arteries partially isolated temporarily from the circulation and studied the rate of its inflow as the arterial pressure fell in consequence of induction of shock. The method is an artificial one whose results 215

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Section: Discussionsupporting

confidence: 66%

The State of the Vessels of the Mesentery in Shock Produced by Constricting the Limbs and the Behavior of the Vessels Following Hemorrhage

Page

Abell

1943

Journal of Experimental Medicine

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“…The effects of L-norepinephrine and angiotonin on nailfold capillary blood flow in man are comparable to those produced in the peripheral circulation in animals. Elevation of arteriaYblood pressure of rabbits with angiotonin, renin, or induced renal hypertension was associated with visible arteriolar constriction in the ear and mesentery, but in contrast to epinephrine and norepinephrine, capillary blood flow and capillary diameter were not decreased (11)(12)(13)(14). In addition, skin temperature was not reduced significantly during injections of renal extracts which elevated arterial blood pressure, renin thus being unique among all other pressor substances (7).…”

Section: Discussionmentioning

confidence: 99%

The Relation of Angiotonin and L-Norepinephrine to Essential Hypertension as Determined by the Reaction of the Nailfold Capillary Bed

Greisman

1956

The Journal of Experimental Medicine

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If a humoral pressor substance is responsible for essential hypertension in man, one of its characteristics should be the ability to constrict the arteriolar bed sufficiently to increase total systemic peripheral resistance, but not sufficiently to reduce cutaneous blood flow. Clinical experience indicates that patients with essential hypertension do not have cold, pale skin reflecting diminished blood flow. More objective studies of total systemic peripheral blood flow in persons with essential hypertension have demonstrated no significant reduction from normal levels (1, 2).This hypothetical pressor substance should also be capable of producing generalized systemic arteriolar constriction without inducing significant constriction or decreased blood flow in a cutaneous capillary bed such as the nailfold. Studies of the nailfold capillary bed in persons with essential hypertension have indicated the absence of significant capillary constriction or decreased capillary blood flow (3, 4).Two naturally occurring pressor agents, norepinephrine and angiotonin, when infused intravenously into persons with normal blood pressure, produce changes in the central systemic circulation similar to those found in persons with essential hypertension (5, 6). The hypertensive state associated with the infusion of norepinephrine however differs markedly from essential hypertension when the circulation in a cutaneous capillary bed such as the nailfold is examined. L-Norepinephrine induces a progressive constriction of this capillary bed as the rate of infusion is increased, so that the nailfold capillary bed is rendered ischemic prior to attainment of hypertensive diastolic arterial blood pressure levels (4).The purpose of the present study was to determine the reaction of a cutaneous capillary bed in persons made hypertensive by the infusion of angiotonin and to compare this reaction with that seen in persons with hypertension induced by L-norepinephrine and in persons with essential hypertension. The vascular bed

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“…Abell and Page 105 have continued to make direct observations on the blood vessels, particularly the arterioles, in the ears of rabbits. Experimental renal hypertension causes constriction in these vessels which is easy to see and which is persistent.…”

Section: Experimental Hypertensionmentioning

confidence: 99%