THE EXPERIMENTAL PRODUCTION OF ASCITES IN THE DOG WITH DIABETES INSIPIDUS 1

Abstract

Progressive ascites were readily produced by constriction of the inferior vena cava at the level of the diaphragm in 2 normal control dogs and in 3 dogs with diabetes insipidus. The diabetes insipidus was induced previously by bilateral destruction of the neurohypophyseal tracts. Rate of formation of ascitic fluid after caval constriction was similar in both groups. At subsequent postmorten little or no anti-diuretic hormone could be demonstrated in the neurohypophysis of the diabetic animals. During ascites formation in normal dogs urine formation tended to decrease, and the urine tended to become more concentrated despite an increase in water intake. On the other hand, among the diabetic dogs, polydysia with the continued excretion of large volumes of dilute urine persisted during accumulation of ascitic fluid. In both groups of animals, the formation of ascites was characterized by nearly maximal renal retention of ingested Na.