[Effect of hypophysin and desoxycorticosterone acetate on kidney function in 3-month-old calves]

The experiment has been carried out on 6 bulls of cb. breed at the age of 3 months. Clearance methods were used to examine the hypophysin (0.1 u V/kg) and desoxycorticosterone acetate (0.1 mg/kg) influence on the size of diuresis, glomerular filtration and excretion of the following: sodium, potassium, chlorides, calcium, magnesium and inorganic phosphorus with urine. Three months old calves had (in comparing to calves in neonatal period) higher glomerular filtration level and lower coefficient of endogenous creatinine purification, however the GFR did not still reach the GFR level of adult animals. Hypophysin and desoxycorticosterone acetate influenced both the process of glomerular filtration (decrease) and tubular transportation of water, Na, K and Cl. After the acetate had been applied, higher condensation of urine was noticed than after the application of hypophysin. Administering DOC to the calves caused decrease in sodium and chlorides excretion with urine as well as increase in kidney purification of potassium. Increased excretion of potassium ion and the decrease in urine pH after DOC injection may suggest that older calves compared with the ones at the age of 2-5 weeks have their kidney mechanism regulating potassium and acid-basic balance developed and efficient. Significant effect of hypophysin and desoxycorticosterone acetate on the process of calcium, magnesium and inorganic phosphorus excretion with the urine has not been stated.