title: Possible involvement of the phospholipases in the mitogenic actions of prolactin (PRL) on Nb2 node lymphoma cells.
abstract: The possible role of the phospholipase enzymes in the prolactin stimulation of mitogenesis in Nb2 node lymphoma cells was investigated. Two phospholipase inhibitors including quinacrine and alpha-para-dibromoacetophenone (BPB) were employed. Quinacrine at concentrations of 1-5 microM attenuated the magnitude of the PRL stimulation of cell division; at concentrations of 10 microM and above quinacrine abolished the PRL response. BPB at concentrations of 1-10 microM also inhibited the mitogenic effect of PRL in a concentration response fashion. The polyunsaturated fatty acid arachidonic acid partially reversed the inhibitory effects of these drugs. In further studies, exogenously added phospholipase C at concentrations of 5-50 ng/ml was found to potentiate the mitogenic effect of prolactin when prolactin was employed at a concentration that evoked a half-maximal response. By itself, however, phospholipase C had no effect on the rate of cell division. Phospholipase A2 either by itself or in the presence of prolactin was without effect.
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D008223:Lymphoma / Q000473:pathology*; D010740:Phospholipases / Q000037:antagonists & inhibitors / Q000502:physiology*; D010741:Phospholipases A / Q000494:pharmacology; D054467:Phospholipases A2; D011388:Prolactin / Q000494:pharmacology*; D011796:Quinacrine / Q000494:pharmacology; D051381:Rats; D013268:Stimulation, Chemical; D010738:Type C Phospholipases / Q000494:pharmacology
chemical_list: D000098:Acetophenones; D001095:Arachidonic Acids; D016718:Arachidonic Acid; D011388:Prolactin; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2; D010738:Type C Phospholipases; D011796:Quinacrine; C006821:4-bromophenacyl bromide