Fate of Angiotensin I in the Circulation

@article{Ng1968FateOA,
  title={Fate of Angiotensin I in the Circulation},
  author={K. K. F. Ng and John Robert Vane},
  journal={Nature},
  year={1968},
  volume={218},
  pages={144-150}
}
  • K. Ng, J. Vane
  • Published 13 April 1968
  • Medicine, Biology
  • Nature
The blood-bathed organ technique has been used to demonstrate that angiotensin I is converted to angiotensin II in the lungs, but not in other vascular beds. The results do not support hypotheses which suggest a completely intra-renal role for the renin–angiotensin system. 
Metabolism of the Angiotensins in Isolated Perfused Tissues
TLDR
Enzymes in isolated vascular beds can fully account for the metabolism of angiotensins I and II in vivo and may not be physiologically important.
The Renin–Angiotensin System: Inhibition of Converting Enzyme in Isolated Tissues
The converting enzyme content of isolated tissues suggests that the indirect action of angiotensin I involves the intramural generation of angiotensin II. Inhibition of the enzyme shows that there is
Pulmonary activation of synthetic angiotensin I.
Recent developments in pathophysiologic studies of the renin-angiotensin system.
  • E. Haber
  • Medicine
    The New England journal of medicine
  • 1969
TLDR
The role of the kidney in the regulation of blood pressure through the mediation of renin was first suggested by the classic experiments of Goldblatt and there was considerable initial confusion about the role of mitochondria.
Angiotensin II‐like activity in circulating arterial blood in immature and adult rabbits
TLDR
Angiotensin II‐like activity was estimated from the contraction of the rat ascending colon superfused with arterial blood in an extracorporeal circuit by infusion of synthetic angiotens in II amide (Hypertensin, CIBA Ltd).
Catabolism of Angiotensin II
TLDR
The generic term “angiotensinase” is used to describe these enzymes, although their specificity is unproven.
Some Properties of Angiotensin Converting Enzyme in the Lung in vivo
TLDR
Bradykinin is inactivated on transit through the pulmonary circulation, but other peptides such as angiotensin II, polistes kinin11 and eledoisin3,4 pass through without loss.
Evidence for the Renal Conversion of Angiotensin I in the Dog
Experiments were carried out on perfused canine kidneys in situ to determine if renal conversion of angiotensin I occurs. Various concentrations of decapeptide produced an immediate increase in renal
Conversion of angiotensin I to angiotensin II.
Mechanism of extraction of angiotensin II in coronary and renal circulations.
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References

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Conversion of Angiotensin I to Angiotensin II
Results obtained with the blood bathed organ technique indicate that angiotensin I is converted rapidly to angiotensin II in the pulmonary circulation and not by an enzyme in the blood.
The continuous estimation of angiotensin formed in the circulation of the dog
1. The use of the rat colon as a blood‐bathed organ is described for detecting changes in angiotensin concentration in the circulating blood of dogs.
Disappearance of Angiotensin from the Circulation of the Dog
TLDR
It is now clear that the blood itself plays little part in the inactivation of angiotensin and that the rapid removal of ang Elliotensin from the bloodstream occurs in the tissues through which it is carried.
Renal Baroceptor Control of Renin Secretion
Small reductions in renal perfusion pressure to levels still within a physiologic range, which did not reduce renal blood flow, caused the kidney to release renin. Renin appeared in much larger
The effects of alteration of blood‐volume on the concentration of circulating angiotensin in anaesthetized dogs
1. The blood‐bathed organ technique was used to assay the concentration of angiotensin in the blood of anaesthetized dogs.
Half-lives of Peptides and Amines in the Circulation
The blood-bathed organ technique, which allows the continuous bioassay of substances in the circulating blood, has been used to measure the half lives of several substances in the circulation.
THE PREPARATION AND FUNCTION OF THE HYPERTENSIN-CONVERTING ENZYME
It has been shown by use of isolated, perfused rat kidneys that hypertensin II is a potent vasoconstrictor substance while hypertensin I is not. Hence it would appear that in intact animals the
A SENSITIVE METHOD FOR THE ASSAY OF ANGIOTENSIN.
TLDR
Under the conditions of the assay, the preparation is sensitive to angiotensin and relatively insensitive to 5-hydroxytryptamine, to histamine and to other substances which might be present in blood.
Hepatic Inactivation of Renin
TLDR
It is concluded that the liver is the major site of renin inactivation in anesthetized dogs and that infusion of exogenous renin decreased the usual renal venous-arterial renin difference.
The disappearance of bradykinin and eledoisin in the circulation and vascular beds of the cat.
TLDR
The infusions were made time to reach equilibrium conditions, as shown by the plateaus of contraction of the assay organs.
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