title: Supernatant factors from short-term cultures of thymocytes: effect on DNA synthesis.
abstract: Supernatants from cultures of unstimulated guinea pig thymocytes were investigated on allogenous thymocytes as regards conditioning effect. DNA synthesis was measured by incorporation of 3H-thymidine. Supernatants taken after different incubation times up to 24 h were used. When used without concentration all supernatants showed stimulating activity. After concentration and fractionation, a stimulating factor was found in supernatants taken after a culture time of 24 h. This factor had a molecular weight above or equal to 70,000 daltons as indicated by gel chromatography. In the same supernatants also an inhibiting factor was indicated.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis*; D006168:Guinea Pigs; D013950:Thymus Gland / Q000378:metabolism* / Q000502:physiology; D013997:Time Factors
chemical_list: D004247:DNA