The Pituitary Gland and the Vascular Tone of the Kidney

Abstract

IN 1940, one of us and M. Dor investigated in the dog the relationship between renal blood flow, systemic pressure and oxygen consumption in kidneys transplanted in the neck. We found that between 60 and 150 mm. Hg. increase in the blood pressure raised the renal blood flow, but that from about 100 mm. up to 160 mm. there was no relationship between blood pressure and blood flow in the kidney. We concluded that "Pour les reins enerves, les valeurs critiques de pression et de debit veineux sont de l'ordre de 130 mm. et 3 c.c. respectivement. Au-dessus de ces chiffres, debit veineux et consommation d'oxygene varient beaucoup plus en fonction d'autres facteurs encore inconnus qu'en fonction du regime de la pression ou de la circulation".Later [Brull and Louis-Bar, 1950], using a mechanical heart with coagulable blood [Brull, 1950], we extended our investigation to include pressures up to the limit of resistance of the renal capsule. The urine flow followed regularly the variations in arterial pressure. The venous flow, although eventually influenced by variations of arterial pressure, did not follow so closely in 7 cases out of 16; it did not respond at all in 9 cases out of 16. We suggested that it was necessary to find out whether the blood carries to the kidney one or several factors which regulate vasomotor responses as well as secretion.In the meantime, Selkurt, Hall and Spencer [1945] investigated, by indirect measurement of the blood flow, the problem which we had studied in 1940. Although unaware of our results, they came to the: same conclusions. In 1951, Shipley and Study perfused kidneys at low, normal and high pressures, using a Dale-Schuster pump and heparinised blood. Unaware of our results of 1950, they too arrived at similar findings, but emphasised that at very high pressures the blood flow, hitherto independent of the pressure, was again influenced. Recently, Brull and Louis-Bar [1953] perfused innervated kidneys in situ, using a mechanical heart with coagulable blood, and showed that innervated kidneys were even more independent of the systemic pressure than denervated ones. Our results were similar to those of Shipley and Studv.151

The effect of posterior pituitary hormones on the excretion of electrolytes, in dogs

“…The present work reinforces the conclusions of Verney (1926) and of Brull & Louis-Bar (1953) that the posterior lobe of the pituitary provides one or more substances affecting renal blood vessels. They believed vasopressin to be of importance.…”

“…He concluded that during its passage through the head the blood picked up a substance or substances which inhibited urine flow and decreased renal blood flow, and that the active material(s) came from the pituitary body. Brull & Louis-Bar (1953) also concluded that the pituitary gland contributed a constrictor substance to the blood, and that in its absence the kidney lost its power of auto-regulation and responded almost directly to changes in systemic blood pressure. These observations demand the re-examination of the role of vasopressin in normal animals.…”

The Nature of the Venous Systems in the Adrenal Gland

“…It is also established that an injection of adrenaline, by evoking renal vasoconstriction, will improve selective adrenal angiography performed via the renal artery (Kahn 1965) by increasing the blood flow, and further proof of this effect has been reported (Dempster 1973). Since renal vasoconstriction is greatly influenced by the action of vasopressin (Brull and Louis-Bar 1953), it is perhaps significant that in the decerebrate animal adrenal blood flow and hormone production are low (Balfour 1953). On the other hand, in the early morning when vasopressin levels are at their highest, adrenal hormone (cortisol) production is also greatly increased and at its daily maximum including plasma 1-tyrosine levels (Pohorecky and Wurtman 1971) at a time when adrenal blood flow is greatly increased (Doe et al 1956;Sjostrand 1934).…”

A Primary Role for Vasopressin in the Genesis of Essential Hypertension

“…The group of normotensives will react with varying Vol.18 No. 4 degrees of reactivity according to the efficiency of the renal-adrenal feed-back system (Fig.1).…”