What question did this study set out to answer?

To identify the blood-borne activators and inhibitors governing angiotonin and renin activity and determine the physiological mechanisms driving angiotonin tachyphylaxis in normal, hypertensive, and nephrectomized animals.

April 1, 1940The Journal of Experimental MedicineOpen Access

Angiotonin-Activator, Renin- And Angiotonin-Inhibitor, and the Mechanism of Angiotonin Tachyphylaxis in Normal, Hypertensive, and Nephrectomized Animals

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Population

Normal, hypertensive, and nephrectomized animals (dogs, rabbits)

Comparison

Intravenous injections and infusions of… vs Baseline responses; comparisons between normal…

Design

Preclinical

Authors

IPIrvine H. PagePennine Acute Hospitals NHS Trust OHO. M. HelmerIndianapolis Zoo

Discussion

Member takes

Implication

Animal data on angiotonin tachyphylaxis and nephrectomy effects; leaves open relevance to human renin-angiotensin regulation.

Key Points

To identify the blood-borne activators and inhibitors governing angiotonin and renin activity and determine the physiological mechanisms driving angiotonin tachyphylaxis in normal, hypertensive, and nephrectomized animals.
Administered serial intravenous injections and continuous infusions of angiotonin and renin to normal, hypertensive, and bilaterally nephrectomized dogs to evaluate pressor responsiveness.
Performed cross-transfusion experiments between tachyphylactic donor animals and nephrectomized or hypertensive recipient dogs.
Tested the vasoconstrictor activity of blood fractions and plasma from treated animals using isolated perfused rabbit ear preparations.
Angiotonin required a specific blood-derived activator from red blood cells and serum to exert vasoconstriction, with repeated administration inducing tachyphylaxis via activator exhaustion and inhibitor emergence.
Bilateral nephrectomy markedly heightened and prolonged the pressor response to angiotonin and renin, peaking 24 to 30 hours postoperatively in parallel with increased blood activator capacity.
Transfusion of blood from angiotonin-tachyphylactic donors significantly suppressed angiotonin-induced pressor and vasoconstrictor responses in nephrectomized recipient animals.

Structured PICO

Population

Normal, hypertensive, and nephrectomized animals (dogs, rabbits)

Intervention

Intravenous injections and infusions of angiotonin and renin

Comparator

Baseline responses; comparisons between normal, nephrectomized, and hypertensive animals

Outcome

Arterial pressure (pressor response) and vasoconstrictor effectsurrogate

This historical preclinical study identifies the role of an 'angiotonin-activator' in the pressor response to angiotonin and elucidates mechanisms of tachyphylaxis and enhanced responsiveness following nephrectomy.

Cite This Study

Page et al. (1940) studied this question.

synapsesocial.com/papers/6a953fec19dbadbb777cf6a7 https://doi.org/10.1084/jem.71.4.495

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Angiotonin-Activator, Renin- And Angiotonin-Inhibitor, and the Mechanism of Angiotonin Tachyphylaxis in Normal, Hypertensive, and Nephrectomized Animals

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Angiotonin-Activator, Renin- And Angiotonin-Inhibitor, and the Mechanism of Angiotonin Tachyphylaxis in Normal, Hypertensive, and Nephrectomized Animals

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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