Hormonal factors affecting sodium excretion in the rat

The actions of a spirolactone and two related compounds in hypophysectomized rats

“…Salt-maintained adrenalectomized rats also failed to respond by change in the rates of urinary excretion of Na and K to the intramuscular injection of the fixed doses of these aldosterone inhibitors (Table 2, MARY F. LOCKETT AND C. N. ROBERTS (experiment 26), which is an effect similar to that produced by aldosterone in such animals (Lockett & Roberts, 1963a, Table 2). Adrenalectomized rats (experiment 21), unable to respond to aldactone by significant change in the urinary output of Na or K, responded after hypophysectomy (experiment 24) to the standard dose of SC-11480 with a marked retention of sodium.…”

“…SC-1 1480 and SC-9420 have a second mode of action which resembles that of aldosterone. It is seen (Table 2, experiments 24 and 26) in their ability to cause retention of sodium in hypophysectomized-adrenalectomized animals and also in summation with the naturetic effects (Lockett & Roberts, 1963a) of aldosterone in hypophysectomized rats (Table 3, experiments 30, 31, 34 and 35). It is seen also on the isolated perfused cat kidney where these compounds sum in their action with aldosterone but do not antagonize (Lockett & Roberts, 1962).…”

“…Animals used in a former investigation (Lockett & Roberts, 1963a) took part in the present work also. Operative techniques and a detailed account of the design of each experiment and of the treatment of data are also to be found in the preceding communication.…”

“…In the previous paper (Lockett & Roberts, 1963a) injections of aldosterone were found to increase the rate of excretion of sodium in hypophysectomized rats. This and other observations discussed in that paper have led us to test the effects of some of these sodium-losing steroids in rats after hypophysectomy.…”

Some actions of growth hormone on the perfused cat kidney

“…The defect in the reabsorption of salt and water is in the proximal parts of the nephron (de Lima & Lockett, 1963) and cannot be corrected by the addition of neurohypophysial hormones alone. Secondly, these kidneys respond to aldosterone by diuresis when perfused with blood from hypophysectomized or headless animals (Davey & Lockett, 1960) as do hypophysectomized rats (Lockett & Roberts, 1963) and the diuresis is often sufficient to bring about increased excretion of sodium in spite of an accompanying reduction in the sodium concentration of the urine (Davey & Lockett, 1960).…”