抄録
Recently, numerous studies were strongly suggestive of the presence of humoral factors in the thymus. To see if the thymuses from myasthenia gravis (MG) produce humoral factors, thymocytes from C57BL/6 mice were incubated with the supernatant from thymic epithelial cultures (STEC) of MG patients. The activity of thymic factor was determined by enhancement of cyclic nucleotides levels in the thymocytes of mice after the addition of STEC. STEC produced marked increase of cAMP levels in thymocytes but not cGMP, whereas the addition of the control media resulted in only modest increase in cAMP. Fractionation of STEC by using Amicon membrane re-vealed that maximal increase in cAMP levels were obtained with a fraction having MW between 10000 and 50000. Thus, these data suggest that the thymuses extirpated from MG patients produce a factor which increases intra-cellular cAMP levels of thymocytes.
