Effects of hormones on development and function of lymphoid tissues. II. Delayed development of immunological capacity in pituitary dwarf mice.

The present report describes the morphology of lymphoid tissues and the humoral antibody response during primary and secondary immune responses to sheep erythrocytes (SRBC) in Snell-Bagg hereditary pituitary dwarf mice. It has been found that while 19S primary response was depressed to a great extent, 7S secondary response reached practically normal levels. Histological studies of the peripheral lymphoid tissues have shown patterns of cellular depletion in nonthymus-dependent areas in dwarfs killed during primary response, while these areas appeared markedly cellular after a second antigenic stimulation. It is suggested that the cell systems involved in antibody production during primary and secondary responses to SRBC may be separate and different. As a result, the endocrine imbalance of the dwarf mice affects only the primary response to SRBC.