A syndrome of sustained elevation of serum sodium and osmolality was produced in cats by injecting 5% silver nitrate (AgNO3) into the perichiasmatic subarachnoid cisterns. Metabolic balance studies showed no significant differences between preoperative and postoperative body weight, urine osmolality, water intake, or urine output. Injury to the supraoptic nucleus of the hypothalamus correlated well with the development of the hypernatremic, hyperosmotic state.
Janice Dorn, Alan B. Rothballer. Essential HypernatremiaThe Experimental Model. Arch Neurol. 1973;28(2):83–90. doi:10.1001/archneur.1973.00490200031003