title: Effects of a hemoregulatory peptide (HP5b) on erythroid and myelopoietic colony formation in vitro.
abstract: A hemoregulatory peptide (HP5b) associated with mature human granulocytes has been investigated for inhibitory effects on murine hemopoietic stem cells in vitro. Both highly purified peptide from natural sources and a synthetic analog peptide have been investigated in parallel. Strong inhibitory effects were found on myelopoietic colony formation in the dose range 10(-13)-10(-5) mol/l. On exceeding this dose, the inhibitory effect disappeared. Moderate to slight inhibitory effects on erythroid colony formation (BFU-E and CFU-E) from adult animals were only seen in 1,000 X the optimal doses for myelopoiesis. No effect was found on CFU-E from fetal liver. The peptide thus has a selective effect on myelopoiesis in a certain dose range. A regulatory mechanism for the peptide on hemopoiesis is proposed.
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells; D003114:Colony-Forming Units Assay; D004920:Erythropoiesis / Q000187:drug effects; D004921:Erythropoietin / Q000494:pharmacology; D006098:Granulocytes / Q000032:analysis; D006410:Hematopoiesis / Q000187:drug effects*; D066298:In Vitro Techniques; D008099:Liver / Q000166:cytology / Q000201:enzymology; D051379:Mice; D009842:Oligopeptides / Q000138:chemical synthesis / Q000494:pharmacology*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives
chemical_list: D009842:Oligopeptides; D004921:Erythropoietin; C040758:hemoregulatory peptide 5b; D011761:Pyrrolidonecarboxylic Acid