“…The duration of the effect of the human hormone was however less than that ofthe bovine hormone, as has been seen throughout the work. Bovine and ovine growth hormones, as previously reported (Lockett & Roberts, 1963), converted the diuretic effect of aldosterone in blood from headless donors (Davey & Lockett, 1960) into an antidiuretic action like that of aldosterone in blood from intact animals. Figure 4 shows that when human growth hormone, 50 ,ug/150 ml., precedes aldosterone, the latter exerts an antidiuretic, sodium and potassium retaining action in blood from headless animals.…”