Autoregulation of renal circulation in mannitol-loaded dogs.
Renal haemodynamics and autoregulatory behaviour of the renal vessels have been investigated in mannitol-loaded dogs both for free-flow and for stop-flow conditions. Arterial pressure has been decreased by aortic clamping. For free-flow conditions: (i) relative constancy of RBF and GFR are well preserved in the entire autoregulatory pressure range, i.e., over 80 mm Hg arterial pressure; (ii) decreased GFR is due to enchanced intratubular pressure; (iii) autoregulation is connected with a sharp rise in afferent resistance, accompained by a passive decrease in efferent resistance. For stop-flow conditions: (i) enchancement of total vascular resistance is due to an increase in the passive resistance of the postglomerular vessels; (ii) afferent resistance drops to minimal values as casused by the relaxation of the corresponding arterioles; (iii) autoregualation is abolished: pressure-flow relations are linear over the entire arterial pressure range examined.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004285:Dogs; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006706:Homeostasis / Q000187:drug effects; D007668:Kidney / Q000098:blood supply* / Q000502:physiology; D008297:Male; D008353:Mannitol / Q000494:pharmacology*; D012039:Regional Blood Flow / Q000187:drug effects; D012044:Regression Analysis; D014655:Vascular Resistance / Q000187:drug effects; D014690:Venous Pressure / Q000187:drug effects
D008353:Mannitol