Examination of the vasopressor responsiveness potentiating plasma factor in hypertensive patients

The vasopressor responsiveness potentiating plasma factor (VPPPF) could be detected in all stages of essential hypertension with the help of cat bioassay. The intensity of the effect was, however, different in the various stages of the disease. Pressure and these subjects did not become hypertensive at a later period. The VPPPF activity was low in one group of subjects with only temporarily high blood members of another group with high VPPPF activity developed later hypertension. Pressure of the hypertensive patients by means of the administration of vasodilators, The VPPPF activity of the blood samples was altered by the reduction of the blood by the alteration of their salt-water balance and by treatment with indomethacin to block prostaglandin synthesis prior to sampling. The observed changes showed partly the same trend and partly a different trend to that of known vasoconstrictor and salt-water retaining hormone responses. The lack of VPPPF in hypertensive patients under regular hemodialysis seems to indicate the renal origin of the factor(s). Mediation of the autonomic nervous system, the alpha-adrenergic receptors and the presence of the kidneys of the bioassay cats play a certain role in the VPPPF effect of hypertensive plasma samples.