THE EFFECTS OF ORTHOSTASIS AND SYNCOPE ON RENAL FUNCTION AND HEMODYNAMICS.
Abstract
Two groups of normal young men have been studied by standard renal clearance techniques while undergoing orthostasis. The subjects in Group 1, who were tilted while bearing their own weight, showed a modest decrease in filtration rate and renal plasma flow, and an insignificant change in the maximum reabsorptive capacity for glucose despite profund antidiuresis. The subjects in Group 2, who were tilted passively, manifested a significantly greater decline in filtration rate and renal plasma flow, concomitant with a general decline in cardiac output and a general indication of the shunting of blood away from the kidney. No evidence of qualitive alterations in renal hemodynamics was observed in response to orthostasis, whether or not syncope ensued. The responses of the normal human kidney to orthostasis, including syncope, were a fall in glomerular filtration rate and an increase in renal vascular resistance with shunting of blood away from the kidney, antidiuresis and antinatriuresis. The data suggested that the renal fraction was a function of the mean arterial blood pressure and multiple mechanisms were responsible for increased sodium and water reabsorption. Syncope did not appear to incite unique response from the kidney. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1968
- Accession Number
- AD0683332
Entities
People
- John J. Simonaitis
- John P. Mcphaul Jr.
- Stanley M. Kleinman