SUB-POPULATIONS OF HUMAN LYMPHOCYTES-T .12. INVITRO EFFECT OF AGENTS MODIFYING INTRACELLULAR LEVELS OF CYCLIC-NUCLEOTIDES ON T-CELLS WITH RECEPTORS FOR IGM (T-MU), IGG (T-GAMMA), OR IGA (T-ALPHA)

  • 1 January 1979
    • journal article
    • research article
    • Vol. 123  (6) , 2664-2668
Abstract
Purified peripheral blood T [thymus-derived] lymphocytes were incubated with inducers of cyclic [c] nucleotides and examined for the numbers of T cells with receptors for Ig[immunoglobulin]M (T.mu.), IgG (T.gamma.) or IgA (T.alpha.). Isoproterenol and theophylline, agents known to increase cAMP levels at 10-3 to 10-6 M concentrations, significantly decreased the number of T.mu. cells but had no effect on T.gamma. or T.alpha. cell numbers. This effect of isoproterenol could be completely blocked by a .beta.-adrenergic blocking agent, propranolol. Receptors for IgM or T.mu. cells regenerated after treatment with theophylline when cells were washed and further incubated at 37.degree. C over a period of 12-24 h in the absence of theophylline. Phenylephrine, at 10-3 to 10-6 M concentrations, significantly increased the numbers of T.mu. cells but had no effect on T.gamma. or T.alpha. cell numbers. The effect of phenylephrine could be completely blocked with an .alpha.-adrenergic blocking agent, phentolamine. The significance of the results was discussed.