[Stress and dietary salt intake in the pathogenesis of hypertension: role of the renal and sympathetic nervous system].
Using the methods of electrophysiology, biochemistry, radioimmunoassay, and electron microscopy, changes of sympathetic nervous system and renal function in hypertensive SD rats induced by stress and high-salt intake were investigated. The results are as follows: (1) Renal plasma flow (RPF) and urinary sodium excretion obviously increased in salt-loading rats. Stress could result in marked reduction of RPF. (2) Electron micrography showed a dramatic increase in cell and mitochondrial volume in the proximal and distal convoluted tubules of high-salt diet rats. After stress of two weeks, the cells of the tubule became atrophic and mitochondrial volume decreased. (3) The same recovery from the declining renal cortical Na-K-ATPase activity in high-salt diet rats could be observed by maintained stress. (4) Low frequency (0.2-0.9 Hz) of BP variability was higher in stress rats as compared to control. (5) Both plasma renin activity (PRA) and angiotensin II (ANG II) levels increased in stress rats, but the decrease in high-salt diet rats gradually reached the high level of the former in two weeks. (6) Increase of BP, fall in RPF, or augment in PRA and ANG II were not observed in stress rats subjected to bilateral renal denervation. The above results indicate that the renal mechanism mediated by increased renal sympathetic nervous system plays an important role in stress- and salt-induced hypertension pathogenesis.
Lin
S T
ST
Department of Nephrology, Huashan Hospital, Shanghai Medical University, Shanghai 200040.
Zou
W Q
WQ
Chen
J
J
Li
P
P
D000818:Animals; D006973:Hypertension / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology*; D007668:Kidney / Q000294:innervation*; D008297:Male; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012982:Sodium, Dietary / Q000008:administration & dosage*; D013312:Stress, Physiological / Q000150:complications / Q000503:physiopathology*; D013564:Sympathetic Nervous System / Q000503:physiopathology*
D012982:Sodium, Dietary