Urinary kallikrein excretion following chronic sinoaortic denervation in conscious dogs

Urinary kallikrein excretion (UKE) was investigated in neurogenic hypertensive dogs for a period of 8 months. The animals were made hypertensive by sinoaortic denervation (SAD). Plasma catecholamine levels (PC), plasma renin activity (PRA), plasma aldosterone concentration (PAC) and urinary sodium excretion (UNa) were also measured. The onset of hypertension was associated with an increase in PC. UKE, measured by amidolytic and kininogenase activities, exhibited a very significant transient increase two and four weeks after SAD. Progressively, UKE significantly decreased below control values at the 16th and 32nd week. Since the month following SAD is characterized by an increase in sympathetic tone (as shown by high PC levels), the transient increase of UKE can be related to this high PC level; although this hypothesis is only supported by a positive relationship between these two parameters. The subsequent decrease in UKE appeared linked to diminished mineralocorticoid activity. Thus, the biphasic pattern of UKE observed in the study suggests that variations of UKE are more a consequence of hypertension than a pathogenic factor. Because UKE, which is of renal origin, is reduced at the end of the study period, this may also suggest possible renal dysfunctions in this model of hypertension.