Renal control of interstitial space compliance: a physiological mechanism which may play a part in the etiology of hypertension.
"Overloading" with salt and water, i.e., increasing extracellular fluid, can, if maintained for a period, lead to hypertension in which the main hemodynamic abnormality is increased peripheral resistance. There is evidence that salt and water overload is the chief factor in the hypertension of the majority of patients suffering from chronic renal failure. "Overloading" occurs not only when the contents of a container are increased, but also when the capacity of a container is decreased. Reduction of the compliance of the interstitial space would reduce its capacity to hold fluid without increase in pressure. Evidence is presented that the presence of the kidney affects interstitial space compliance; bilateral nephrectomy decreases interstitial space compliance four fold. Hypertension induced by renal artery partial constriction and removal of the other kidney is also associated with reduction of interstitial space compliance; a sudden rise in interstitial space compliance may be the primary factor in the course of events that leads to the rapid fall in blood pressure which occurs when the constriction is removed from the renal artery. It is suggested that the kidney secretes a hormone which increases interstitial space compliance and that this represents a physiological mechanism which enables animals to store water in the interstitial space without undue rise in interstitial tissue pressure. The role of this mechanism in hypertension and in chronic renal failure is discussed.
D000818:Animals; D002908:Chronic Disease; D003187:Compliance; D005110:Extracellular Space / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000209:etiology*; D006977:Hypertension, Renal / Q000209:etiology*; D007668:Kidney / Q000503:physiopathology*; D009392:Nephrectomy; D011312:Pressure