STIMULATION OF ACTIVE SODIUM TRANSPORT ACROSS THE ISOLATED TOAD BLADDER AFTER INJECTION OF ALDOSTERONE TO THE ANIMAL¹²

Stimulation of Active Sodium Transport by the Isolated Toad Bladder With Aldosterone in Vitro*

“…In a series of 8 experiments, studies were performed on the short-circuited membrane, using NaM and Na" to measure the two unidirectional sodium fluxes simultaneously (9). Bladder tissue was analyzed for water, sodium, potassium, and chloride content as previously described (11). Tissue glycogen concentration was determined by the anthrone method (12), after alkaline digestion of tissue samples stored frozen after incubation and weighing.…”

“…DISCUSSION These results demonstrate that active sodium transport can be stimulated by aldosterone in vitro. Concentrations of hormone less than seven times those found in the circulating blood of toads maintained in distilled water (11) were sufficient to elicit a significant elevation of the short-circuit current. The latter was shown to represent net sodium transport quantitatively.…”

“…Thus the increase of short-circuit current was almost exactly the same for both groups of bladder halves. The additive character of the response of sodium transport to vasopressin and aldosterone has already been noticed after stimulation of sodium transport by injection of aldosterone into toads ( 11 ). When sodium transport was stimulated-by injection of sodium-retaining steroid into water toads, a brisk response of sodium transport was still obtained after addition of vasopressin, even though these membranes no longer responded to aldosterone in vitro (Table V).…”

“…These investigators have shown that, when an external potential is applied so as to * Presented in part at the Annual Meeting of the American Society for Clinical Research, Atlantic City, N. J., May, 1960. This work was supported in part by grants from the John A. Hartford Foundation, Inc., the United States Public Health Service (H-2822) and the American Heart Association, Inc. t Previous experiments have established that aldosterone is a physiological hormone for the toad, Bufo marinus, and that sodium transport by the toad urinary bladder is stimulated after injection of the steroid into the animal (11). For the present studies the membrane was exposed to aldosterone in vitro, and stimulation of active sodium transport ensued.…”

Augmentation of nuclear binding capacity for triiodothyronine by aldosterone in tadpole tail.

“…In anurans, adorenocortical tissue secretes principally two hormones, aldosterone and corticosterone (Carstersen et al, 1961;Crabbe, 1961). Dale (1962) reported that in metamorphosing tadpoles of Rana pipiens and Rana silvatica, aldosterone level is elevated.…”