Effects of salt restriction on blood volume, hemodynamics and humoral factors in hypertensive patients with chronic glomerulonephritis.
In order to elucidate the pressor mechanism in renal parenchymal hypertension, we examined blood volume, hemodynamics, and humoral factors, before and after salt intake restriction from 10 to 2 g daily, in patients with chronic glomerulonephritis (GN), with and without hypertension, and in a normotensive control group. Such salt restriction reduced body weight, blood volume, cardiac index (CI) and urinary sodium excretion equally in all groups, whereas mean blood pressure was reduced by 16 mm Hg in only ten hypertensive GN, but not in normotensive GN and the control group. In hypertensive GN the reduction of blood pressure was accompanied by blunt responses in the total peripheral resistance index (TPRI) and plasma norepinephrine (PNE). By contrast, in normotensive GN and the control group the reduction of CI was compensated for by increased TPRI, resulting in unchanged blood pressure. Among GN with and without hypertension, changes in TPRI by salt restriction were significantly correlated with changes of PNE. In conclusion, renal parenchymal hypertension is sustained by elevated vascular resistance and increased plasma norepinephrine as well. Blood pressure reduction by salt restriction is consistent with the low responses in TPRI and PNE.
Kumagai
H
H
2nd Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Onoyama
K
K
Fujishima
M
M
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure; D001810:Blood Volume; D002908:Chronic Disease; D003404:Creatinine / Q000097:blood; D004039:Diet, Sodium-Restricted; D005260:Female; D005921:Glomerulonephritis / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D006977:Hypertension, Renal / Q000178:diet therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D011188:Potassium / Q000097:blood / Q000652:urine; D012083:Renin / Q000097:blood; D012964:Sodium / Q000097:blood / Q000652:urine; D014655:Vascular Resistance
D012964:Sodium; D003404:Creatinine; D012083:Renin; D011188:Potassium; D009638:Norepinephrine