Effects of handling on weight gains and endocrine organs in mature male rats

¹ Laboratories for Therapeutic Research, Brooklyn College of Pharmacy, Long Island University, Brooklyn, New York

Daily handling of young mature rats over a 3-week period significantly increases their body weight gains in much the same fashion as does the handling of preweanling and weanling rats. Significant increases were also observed in the adrenals, testes, seminal vesicles, spleen and liver organ weights. Although mechanisms involved in the handling effect are not clearly defined, the findings have methodologic significance. The marked influence of handling on weight gains and organ weights indicates the need for careful regulation of the handling of control and experimental animals in all endocrine studies. The study indicates that the stimulatory effects of handling on body growth and development are not necessarily limited to the early developmental period.