Effect of bovine growth hormone administration on the pattern of thymic involution in mice.

Abstract

Age-related decline of the thymus in mice was reversed by repeated injections of bovine growth hormone. After hormone administration that was begun at 5, 8, or 11.5 months of age, the cortical volume fraction (Vc), cortical/medullary ratio (C/M) and thymocyte numbers found were in the range obtained with younger mice. Growth hormone injection reduced the slope of the curves for Vc and C/M as a function of age, indicating a slowing down of the involution process.