Terminal aortic response to sodium intake is the major determinant of total peripheral resistance in elderly hypertensives.
Thirty-four elderly patients were studied using a Doppler flowmeter during different sodium intakes. Salt increased mean blood pressure and cardiac output (CO), while total peripheral resistance (TPR) remained unchanged. Neither carotid nor terminal aortic resistance changed, while coeliac, superior mesenteric or renal resistance increased. There was a significant and direct correlation (r = 0.82) between the change in TPR and that in terminal aortic resistance. Salt-sensitive patients were divided into two subgroups; the SST group in which sodium loading increased TPR more than CO, and the SSC group in which salt loading increased CO more than TPR. Terminal aortic resistance increased in the SST, decreased in the SSC, and remained unchanged in the non-salt-sensitive group with salt loading. The terminal aortic vascular bed received much of the increase of CO in the SSC patients. In the SST group, the contribution of the individual vascular area to increased TPR was assessed, which revealed that terminal aortic response to sodium loading was the major determinant of increased TPR. We concluded that the responses of terminal aortic vascular bed to sodium loading contributed to the changes in TPR.
Shimamoto
H
H
First Department of Internal Medicine, Hiroshima University School of Medicine, Japan.
Shimamoto
Y
Y
D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000187:drug effects* / Q000503:physiopathology; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D012039:Regional Blood Flow / Q000187:drug effects; D012964:Sodium / Q000494:pharmacology*; D014655:Vascular Resistance / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects
D012964:Sodium