ROLE OF THE KIDNEY IN THE FORMATION OF ACTIVE POLYPEPTIDES IN THE BLOOD.
Final rept., 15 Mar 66-15 Mar 67,
UNIVERSIDAD CATOLICA DE CHILE SANTIAGO LABORATORIO DE FISIOLOGIA
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The blood serum of different species man, horse, dog, cat, rat, chicken incubated at 37C at normal pH sets free vasoactive substances. These are neither bradykinin nor angiotensin they are large proteins. These were separated and purified by gel filtration. One of them, the biggest molecule has been designated peak 1. This purified fraction under the action of pepsin releases a bradykinin-like polypeptide. The other one, called peak 2, under the action of the same enzyme sets free an anephrotensin-like polypeptide. The serum obtained from nephrectomized dogs and rats exhibits during incubation at 37C at normal pH a lower yield of vasoactive proteins peak 1 and peak 2. Proteins peak 1 and peak 2 are the precursors of the polypeptides which accumulate in the serum during incubation at acid pH. In the serum incubated at acid pH the substances formed during incubation are dialyzable polypeptides. The effect of growth hormone on renal excretion, and the effects of anephrotensin on the depletion of suprarenal ascorbic acid were also studied. According to the results obtained, anephrotensin, bradykinin and angiotensin II valyl 5 produce ascorbic acid depletion in the adrenal gland and an increase in the corticosteroids in the blood. Both effects can be blocked by hypophysectomy or giving morphine, previously to the polypeptide injections. Author
- Anatomy and Physiology