A novel computer-driven, servo-controlled fluid replacement technique and its application to renal function studies in conscious rats.
1. A new rat model has been developed allowing body fluid status to be accurately controlled and maintained throughout experimentation by computer-driven, servo-controlled replacement of spontaneous urinary fluid losses. 2. Experiments in vitro were performed to test the accuracy of the servo system, and experiments in vivo were carried out to re-assess basic renal function in servo-controlled vasopressin-replete Long Evans and vasopressin-deficient Brattleboro rats. The model was further evaluated in water-diuretic Wistar rats with or without administration of a vasopressin V2-receptor agonist, 1-desamino-8-D-arginine vasopressin. 3. The data gained from the present study indicate the suitability of the servo-controlled replacement system for conscious renal function studies in three different rat strains. Haemodynamic and renal function variables measured were demonstrated to be stable throughout a 5 h experimental procedure and reproducible between repeated experimental occasions over a 14 day post-operative period. 4. Using the servo-control technique, the expected action of 1-desamino-8-D-arginine vasopressin on renal water handling was demonstrated, but the natriuretic effect reported by some workers was not evident. 5. Since the servo-controlled fluid replacement technique maintains many of the inherent differences between vasopressin-replete Long Evans and vasopressin-deficient Brattleboro rats and eliminates the changes in body fluid volume during transition from a diuretic to an antidiuretic state, the model confers an advantage over previously employed constant infusion protocols.
Burgess
W J
WJ
Department of Physiological Sciences, University of Manchester, U.K.
Shalmi
M
M
Petersen
J S
JS
Plange-Rhule
J
J
Balment
R J
RJ
Atherton
J C
JC
D000818:Animals; D001826:Body Fluids / Q000502:physiology*; D002138:Calibration; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology; D004231:Diuresis / Q000187:drug effects / Q000502:physiology; D007260:Infusion Pumps; D007668:Kidney / Q000502:physiology; D007677:Kidney Function Tests / Q000379:methods*; D008297:Male; D008838:Microcomputers; D008954:Models, Biological; D051381:Rats; D011910:Rats, Brattleboro; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D015203:Reproducibility of Results
D003894:Deamino Arginine Vasopressin