title: Cholinergic enhancement of megakaryocytopoiesis and granulocytopoiesis in culture: mediation via T-lymphocytes.
abstract: Addition of carbamylcholine, a cholinergic analogue, to bone marrow cultures enhanced megakaryocytic and granulocytic growth by 60% and 42%, respectively. When carbamylcholine was added to spleen cells cultured in the presence of pokeweed mitogen, the resulting conditioned medium (PWM-SCM) increased the number of megakaryocytic and granulocytic colonies to 159% +/- 6% and 146% +/- 10%, respectively, compared to control cultures stimulated by PWM-SCM alone. To determine if this cholinergic augmentation of colony formation was direct or mediated via accessory marrow cells, cyclosporin A (CyA), a potent T-lymphocyte function inhibitor known to suppress the production of colony-stimulating activity (CSA) by spleen cell cultures, was added to marrow cultures. CyA (3 micrograms/ml) abrogated the enhancement of megakaryocytic and granulocyte-macrophage colony growth but had no effect on colony formation when added alone. To confirm the role of T-lymphocytes in the augmented proliferation of megakaryocytopoiesis and granulocytopoiesis, bone marrow cells from T-lymphocyte-deficient nude mice were cultured in the presence of carbamylcholine. No significant change was observed in the number of megakaryocyte colony-forming units (CFU-M) and committed granulocyte-macrophage colony-forming units (CFU-C) derived from the marrow of nude mice when cultured in the presence of carbamylcholine. The data suggest that carbamylcholine-induced enhancement of megakaryocytopoiesis and granulocytopoiesis in culture is indirect, requiring a T-lymphocyte population.
authors.affiliation: Laboratory of Experimental Oncology and Hematology, Catholic University of Louvain, Brussels, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Chatelain
authors.forename: M
authors.initials: M
authors.lastname: Hamood
authors.forename: M
authors.initials: M
authors.lastname: De Bast
authors.forename: M
authors.initials: M
authors.lastname: Symann
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells; D002217:Carbachol / Q000494:pharmacology*; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D003524:Cyclosporins / Q000494:pharmacology; D006098:Granulocytes / Q000502:physiology*; D006410:Hematopoiesis / Q000187:drug effects*; D066298:In Vitro Techniques; D008533:Megakaryocytes / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D003524:Cyclosporins; D002217:Carbachol