[Pentacyclic triterpenes and ion excretion by rat kidneys].

Experiments were conducted on rats. A study was made of water, sodium, potassium and creatine excretion 3 hours after the administration into the stomach of a 5% load with a 0.9% NaCl solution. In comparison with control, sodium excretion decreased considerably in the animals given 2 mg per 100 g of weight of trioxylupane or heterobetulin; water, potassium and creatine excretion remained unchanged. Sodium and water excretion increased with administration of dioxylupenal in a dose of 2 mg per 100 g of weight. Heterobetulin also increased the urinary potassium excretion under conditions of administration to rats of a 5% load with a 1.25% KCl solution. The data obtained were of interest for the understanding of the interrelationship between the structure of the substances and their physiological activity.