RECOVERY FROM DISORDERED DRINKING BY VAGOTOMIZED RATS

Within 8 weeks after bilateral subdiaphragmatic vagotomy, rats failed to respond to 3 stimuli of thirst: water consumption in absence of food, cellular dehydration produced by hypertonic NaCl, and beta-adrenergic activation using isoproterenol. Sixteen weeks post-surgery, however, these deficits in drinking behavior disappeared. Eight weeks after surgery, for example, following intragastric loads of 5% NaCl at 1 ml/100 g body weight, vagotomized rats drank 2.3 ± 0.3 ml water; their sham-operated controls drank 17.4 ± 1.6 ml. The corresponding values 16 weeks post-surgery were 17.4 ± 0.7 for the vagotomized rats and 17.9 ± 0.7 ml for the laparotomized controls. When isoproterenol (0.05 mg/100 g) was injected, for the initial tests vagotomized rats and their controls drank 3.2 ± 0.3 ml and 15.8 ± 0.8 ml water, respectively, and the corresponding values 16 weeks post-surgery were 15.8 ± 0.7 ml and 14.9 ± 0.7 ml, respectively. There was no recovery of efferent vagal function so recovery of drinking was probably not due to nerve regeneration. © 1979.