Abstract
The writers have reported that a commercial extract of the anterior pituitary prolongs the life-span of bilaterally adrenalectomized cats, but is without effect upon dogs, at any rate in the dosage employed. 1 Two of the 12 animals studied were castrate males. One lived 25 days and succumbed to feline distemper; the other survived 47 days. It was deemed worth while to study the effect of A.P. extract upon the life-span of a larger group of castrate-adrenalectomized cats.
Strong, vigorous cats were used. They were given a vermifuge, and a few days later the gonads and right adrenal were removed under nembutal anesthesia. They were then kept in the laboratory for 2 weeks to insure adjustment to laboratory conditions. The animal room was thermostatically regulated. The left adrenal was extirpated under ether and for 2 days following operation the cats received cortical hormone. If the animals were eating full rations at this time cortical hormone was withdrawn and A.P. extract substituted. The experiment began the day cortical hormone was discontinued.
The A.P. extract used was prepared by a modification of the method of Van Dyke and Wallen-Lawrence2 and is an alkaline aqueous extract of cattle pituitary made by Squibb & Sons. It contains appreciable amounts of the various pituitary factors. We used freshly prepared non-preserved material since the cats appeared to he sensitive to the merthiolate present in the commercial preparation.
The diet consisted of 175 g of canned salmon plus 50 cc of milk daily. This was changed to fresh raw fish, liver and kidney whenever the appetite became capricious. The essential data regarding the effect of A.P. extract upon the life-span are shown in Table I.
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