title: Synergistic effect of phorbol myristate acetate on bacterial lipopolysaccharide induced rat splenocyte proliferation.
abstract: 1. Bacterial lipopolysaccharide (LPS) stimulated [3H]TdR incorporation of rat splenocytes in a concentration dependent manner. 2. Phorbol 12-myristate 13-acetate (PMA) alone has little effect on rat splenocyte proliferation but it exerted a marked synergistic effect on LPS-induced [3H]TdR incorporation when added at the first few hours of incubation with LPS. Minimal synergistic effect of PMA was observed if it was added later than 4 hr after LPS application. 3. Both LPS-stimulated and PMA synergized incorporation of [3H]TdR in rat splenocytes were inhibited by H-7, a protein kinase C inhibitor. 4. The results support the notion that the activation of protein kinase C is a necessary but insufficient cellular signal in the initiation of proliferative response of rat splenocytes by LPS.
authors.affiliation: Chinese Medicinal Material Research Centre, Chinese University of Hong Kong, Shatin.
authors.forename: H
authors.initials: H
authors.lastname: Xu
authors.forename: L F
authors.initials: LF
authors.lastname: Lau
authors.forename: C M
authors.initials: CM
authors.lastname: Lee
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D004357:Drug Synergism; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000008:administration & dosage* / Q000494:pharmacology; D008297:Male; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000008:administration & dosage* / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors
chemical_list: D007546:Isoquinolines; D008070:Lipopolysaccharides; D010879:Piperazines; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D013936:Thymidine