Role of Cyclic Nucleotides in the Regulation of Lymphocyte Transformation
Annual progress rept. 1 Jun 1974-31 May 1975
VETERANS ADMINISTRATION HOSPITAL PITTSBURGH PA
Pagination or Media Count:
Studies were conducted to define the roles of cyclic-AMP cAMP and cyclic-CMP cGMP in lymphocyte mitogenesis. The lymphocyte mitogens staphylococcal enterotoxin BSEB, concanavalin-A CON-A, phytohemagglutinin PHA, and endotoxin, did not stimulate the adenylate cyclase-cAMP system of human or rodent lymphocytes. Similarly, no effect of SEB, CON-A, and PHA on rodent lymphocyte cGMP content was observed during incubations up to 2 hours. Nevertheless, clear-cut and diametrically opposite effects of cAMP and cGMP on lymphocyte DNA synthesis were demonstrated, with cAMP inhibiting and cGMP potentiating this process. These results suggest that the intracellular levels of cAMP and cGMP may be important determinants of lymphocyte growth. However, mitogens do not appear to mediate rapid changes in lymphocytes in cyclic nucleotide content.