Renal Medulla and Renoprival Hypertension
Relationship Between Corticorenal (Renin) And Medullorenal Extracts
A crude extract of renal medulla (medullorenal extract) has been studied in relation to a crude extract of renal cortex which possessed potent renin pressor activity. The medullorenal extract either effected no immediate change in the arterial pressure or caused a mild to moderate pressor effect. The latter was thought to be due to contamination with renin, since precise separation of cortex and medulla may not have been consistent. The medullorenal extract did not display a sustained, acute depressor effect. The extract was not pyrogenic in rabbits.
The production of renin pressor effect in nephrectomized dogs did not alter the evolution of renoprival hypertension. The mixture of renin and nonrenal extracts did not alter the evolution of renoprival hypertension in the dog. The medullorenal extract, on the other hand, prevented renoprival hypertension in the presence of daily renin pressor responses. The latter results were similar to those obtained when renin was infused in normal dogs.
The results suggest that the medullorenal extract protected against renoprival hypertension by a route other than one directly related to the renin-angiotensin system. Such a route could be due to an effect on small arteries and arterioles. The results also are consistent with an active principle in the medullorenal extract which reproduces the function of intact renal tissue.
- Received April 2, 1962.
- © 1962 American Heart Association, Inc.