RENAL HANDLING OF LITHIUM - RELATION BETWEEN LITHIUM CLEARANCE, SODIUM CLEARANCE AND URINE FLOW IN RATS WITH DIABETES-INSIPIDUS

  • 1 January 1977
    • journal article
    • research article
    • Vol. 40  (4) , 491-496
Abstract
To study the renal handling of Li, the relation between the Li clearance and the urine flow in rats, which had hereditary lack of vasopressin production and which were given a test dose of Li, were examined. The 2 variables were altered by varying the Na intake. Rats with a low, medium and high Na intake had a mean Li clearance of 0.04, 0.22 and 0.40 ml/min per 100 g body weight, respectively. When the Na intake was increased from a medium to a high level, the Li clearance and the urine flow rose in proportion to each other (r = 0.90). When the Na intake was decreased from a medium to a low level, the Li clearance fell relatively more than the urine flow so that the proportion between the 2 was changed. When vasopressin-induced alterations of the urine flow were excluded and when the Na intake was not extremely low, proportionality may occur between the Li clearance and the urine flow. The Li clearance probably varied in proportion to and was determined by the delivery of Na from the proximal tubules.