NE turnover in genetically hypertensive rats of Lyon strain. II. Peripheral organs.

The peripheral sympathetic nervous system (SNS) is a major determinant of blood pressure and is likely to be involved in the pathophysiology of hypertension. Because SNS activity varies among organs, we measured the in vivo turnover (TO) of norepinephrine (NE) in seven organs of 5- and 22-wk-old genetically hypertensive (LH), normotensive (LN), and low blood pressure (LL) rats of the Lyon strains. The TO of NE was found normal in the superior cervical ganglia and decreased in the heart of 5-wk-old LH rats compared with both LL and LN controls. This suggests that sympathetic cardiac innervation may not be involved in the development of hypertension. On the contrary, an increased TO of NE in the kidney cortex and an elevated TO of dopamine associated with an increased epinephrine content in the adrenal medulla were observed in 5-wk-old LH rats, which could participate in the development of hypertension in the Lyon model.