Characterization of lactogen receptors in lactogenic hormone-dependent and independent NB2 lymphoma cell lines.
A comparative study of lactogen receptors in lactogenic hormone-dependent (Nb2-11C) and independent (Nb2-SP) rat lymphoma cell lines revealed no significant differences in their binding and structural characteristics. The affinity for human growth hormone (hGH) and ovine prolactin is identical (Kd = 1.3 X 10(-10) M). Exposure to hGH results in a rapid receptor down-regulation. This process is faster in Nb2-SP cells, however, similar receptor levels are reached within 3 h. Affinity labeling revealed 2 major binding species (Mr 75,000 and 29,000) in both cell lines. These observations suggest that the spontaneous proliferation of Nb2-SP cells probably results from an aberration in some post-receptoral event of the mitogenic pathway.
D000818:Animals; D001667:Binding, Competitive; D002460:Cell Line; D006801:Humans; D007700:Kinetics; D008223:Lymphoma / Q000378:metabolism*; D008861:Microsomes / Q000378:metabolism; D010928:Placental Lactogen / Q000378:metabolism / Q000494:pharmacology*; D018000:Receptors, Peptide; D011981:Receptors, Prolactin / Q000378:metabolism*; D012756:Sheep
D018000:Receptors, Peptide; D011981:Receptors, Prolactin; C028202:placental lactogen receptor; D010928:Placental Lactogen