title: Renal blood flow varies during normal activity in conscious unrestrained rats.
abstract: The extent to which renal blood flow (RBF) varied during normal daily activity and its dependence on renal nerve activity were studied in unrestrained rats. RBF (measured with a pulsed Doppler flow probe) and behavior pattern (observed with a video camera) were recorded during both phases of the light-dark cycle (n = 11). RBF was highest (100%) when the rat was fully relaxed and apparently asleep (9% time) but was significantly lower (P less than 0.01) during the remainder of the time. When quiescent but not fully relaxed, RBF was 89.7 +/- 0.3% of the maximum; when alert and completely still, it was 74.1 +/- 0.8%; and when grooming, it was 63.7 +/- 0.9%. Mean daily RBF was 80% of maximum flow. During saline infusion into cuffs around the renal arteries, RBF was reduced to 38.4 +/- 0.7% of maximum flow by gentle handling. When the infusion was changed to Xylocaine (5%), which blocked transmission in the renal nerve, similar treatment reduced RBF to 80.2 +/- 0.7% with ipsilateral and to 94.7 +/- 0.7% with bilateral infusions. We conclude that RBF varies considerably in unrestrained animals under normal conditions and that the variations largely result from changes in renal nerve activity.
authors.affiliation: Department of Physiology, University of Auckland School of Medicine, New Zealand.
authors.forename: H C
authors.initials: HC
authors.lastname: Grady
authors.forename: E M
authors.initials: EM
authors.lastname: Bullivant
mesh_terms: D000758:Anesthesia; D000818:Animals; D001463:Barbiturates; D001522:Behavior, Animal / Q000502:physiology; D006234:Handling, Psychological; D007267:Injections; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012077:Renal Artery; D012079:Renal Circulation; D012149:Restraint, Physical
chemical_list: D001463:Barbiturates; D008012:Lidocaine