ABSTRACT
Abstract--In order to investigate the role of central and peripheral sympathetic activities in strokeprone spontaneously hypertensive rats (SHRSP), maximum dose of 6-OHDA was injected into a lateral cerebral ventricle (i.e. v.) or a peritoneal cavity (i.p.), and changes of catecholamine metabolites in the brain, adrenal glands, plasma, and urine were measured and analyzed. 6-OHDA i.e.v. showed no changes in blood pressure, but showed a tendency to lower heart rates, and a significant decrease in NE in the brain and plasma in SHRSP. On the other hand, 6-OHDA i.p. showed a significant decline of blood pressure, an increase in heart rate, and a decrease of Ep in plasma without effects on NE level in SHRSP. These findings indicate that (1) 6-OHDA i.p. treatment destroys the accessory or extra-adrenal glands besides peripheral sympathetic nerves; (2) Ep is released from the extra-secretary organs, and contributes to maintaining the hypertension in SHRSP; (3) 6-OHDA i.c.v. destroys the central sympathetic nerves and inhibits temporally the peripheral sympathetic activity, adrenal glands and the accessory or extra-adrenal glands; and (4) peripheral sympathetic nerve function works to maintain hyper-sympathetic states in SHRSP.
