The question whether diuretics, besides exerting a direct renal action, have a pre-diuretic effect on the tissues has long been debated. In the present study the problem has been approached by determining simultaneously the amounts of sodium, potassium and chloride in plasma and skin of mice treated with the mersalyl-theophylline complex.
MethodsWhite male mice of the Leo-strain, weighing from 22 to 27 g, were divided into two groups; one was treated with S.C. oestradiol monobenzoate, 10 pg in 0.1 ml of arachis oil injected 6 and 4 days before the experiment. On the day of the experiment the animals were placed on pieces of filter paper. As spontaneous urination occurred, 0.1 ml of a I :20 dilution of injectabile mersalyli (Ph. Dan. 1948, mersalylum g 100, theophyllinum g 50, I N-NaOH q.s., sterile water to lo00 ml) in 0.9% NaCl, i.e. 20 mg of mersalyl per kg body weight, was injected intraperitoneally. Control animals received 0.1 ml of 0.9% NaCI. Twenty minutes after the injection (the animal did not void during this period), the animal was stunned by a blow on the neck, the urethra was immediately closed by a clamp, and 500 PI of blood were sampled through an incision in the right side of the neck. After beheading and bleeding the animal, the bladder was emptied and the urine measured with a tuberculin syringe. The skin on the back was depilated, and a specific area was marked by a stamp. This area of the skin, with its underlying subcutaneous tissue, was excised and weighed, freeze-dried to constant weight, defatted to constant weight and subsequently analysed. Hexosamine, hydroxyproline, sodium, potassium and chloride determinations on the skin, and sodium, potassium and chloride determinations on the plasma were carried out as described by LANGGARD, JENSEN-HOLM & HVIDBERG (1 963).
