Hyperdipsia induced by bilateral destruction of the locus coeruleus in rats

Bilateral lesions in the locus coeruleus (LC) of rats induced a urinary disorder and hyperdipsia. Dilatation of the urinary bladder, urinary retention and hematuria with bleeding originating from the urinary bladder, occurred immediately after the lesioning and continued for 2-5 days. Water intake increased 4 days after the lesioning. This hyperdipsia persisted for at least 4 days and then gradually returned to the control level. Food intake decreased for the first 5 days, and then returned to the control level. Lesions in the ascending dorsal bundle (DB) originating from the LC also produced hyperdipsia, but not urinary disorder. Destruction of the ascending ventral vundle (VB) originating from the noradrenaline (NA) neurons in the medulla oblongata did not affect eating, drinking or urination. The LC- or DB-lesioning caused a significant reduction of NA in the whole forebrain except the hypothalamus, whereas VB-lesioning caused reduced NA in the hypothalamus. In LC-lesioned animals, no significant changes were observed in serum osmolarity, Na+, K+, albumin and glucose in serum, or in the excretion of urine in the water-loading test.