Possible involvement of the phospholipases in the mitogenic actions of prolactin (PRL) on Nb2 node lymphoma cells.
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.
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
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