[Intrathymic regulation of proliferation of medullary thymocytes in CBA mice]

The action of non-peptide mitogenic factor (NMF) on the following thymocytes populations: common cortisone-resistant (CR); cortisone-resistant cells without macrophages (CR-M) and mature (PNP-) thymocytes was studied. It has been shown, that NMF shifts the catabolism of (8-(14) C) AMP towards hypoxanthine accumulation as well as stimulates the (2(-14) C) Thd incorporation in DNA of thymocyte populations to an increasing degree when comparing CR with PNA- cells. The action of NMF is not mediated by macrophages. It has been concluded that mature PNP- population is the target for NMF.