Effects of Prolonged Daily Treatment of Normal Rats with Saline Anterior Pituitary Extract

Abstract
The effects on appetite, growth and organ weight of normal male and female rats treated daily during a period of 12 to 14 weeks with a 1% saline extract of bovine anterior pituitary lobes have been investigated by paired and ad libitum feeding. In male rats there was no specific growth stimulation independent of food intake. An initial appetite-stimulating effect accounted for the extra gains in weight of treated male rats fed ad libitum. This effect gradually disappeared, and during the final 7 weeks the appetites of the treated male rats were depressed, and growth was retarded independently. In female rats appetite and growth were stimulated independently. Treated females pair-fed with controls showed extra gain in body weight after the fifth week of treatment, while those fed ad libitum grew at about the same rate as normal untreated male rats. The liver weights of the treated rats of both sexes were less than those of the controls, on the basis of equal body weight. The weights of the adrenals and thyroids in the treated male rats were larger than those of the controls, but no difference in the weights of these glands was evident in the female rats. The effect on adrenals in the treated males appeared to be a true enlargement, but the difference in thyroid weight resulted from a decrease in the weight of these glands in the control rats rather than from an enlargement in the treated rats.