LYMPHOCYTES-T AND LYMPHOCYTES-B IN PITUITARY DWARF SNELL-BAGG MICE

  • 1 January 1979
    • journal article
    • research article
    • Vol. 38  (1) , 23-31
Abstract
Lymphocyte composition of the thymus and spleen from weaned (4 mo. old) hypopituitary dwarf Snell-Bagg mice were compared to those of their phenotypically normal littermates and of hormone (somatotropic hormone plus thyroxine)-treated individuals. Detection of cells bearing receptors for peanut agglutinin, physical analysis and measurement of in vitro reactivities to phytohemagglutinin and concanavalin A revealed the lack of clear-cut qualitative or quantitative alteration in the intra-thymic lymphocyte population of dwarf mice. Examination of spleen-cell suspensions demonstrated a slightly higher frequency of T [thymus-derived] lymphocytes (Thy 1-2+, .alpha.-naphthyl esterase+, high electrophoretic mobility) and lower frequency of B [bone marrow-derived] lymphocytes (surface immunoglobulin+, low electrophoretic mobility) in dwarf mice than in control mice. Degree of splenocyte responsiveness to T and B cell mitogens, was similar in the 2 mouse types. High mobility (T) splenic cells exhibited a smaller modal volume in dwarf mice (110 .mu.m3) than in control mice (122 .mu.m3) but this difference was not corrected by hormone administration. More pronounced were the quantitative differences between spleens of hormone-deficient and normal mice. Thus, when expressed as a function of body wt, the numbers of splenic T and B lymhocytes in untreated dwarf mice were about half the corresponding values in hormone-reconstituted or normal littermates. In adult life, developmental hormones apparently exert little direct effect on thymus lymphocytes but influence the size of the pool of both peripheral T and B lymphocytes.