Increased kallikrein excretion in spontaneously hypertensive rats and its inhibition by 6-hydroxydopamine.

Urinary kallikrein excretion was studied in young, stroke-prone, spontaneously hypertensive rats (spSHR). Seven-week-old spSHR were found to excrete more kallikrein into the urine than normotensive Wistar Kyoto control rats (WKR). "Chemical sympathectomy", induced by 6-hydroxydopamine (6-OHDA) immediately after birth, resulted in normotensive blood-pressure levels and in a reduction of kallikrein in spSHR. In normotensive WKR, blood pressure and urinary kallikrein excretion were only slightly diminished by 6-OHDA. The results suggest a relationship between sympathetic activity and kallikrein excretion, being especially pronounced in spSHR, which have an elevated sympathetic activity.