losartan-potassium and hemoregulatory-peptide-5b

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.

Topics: Animals; Bone Marrow Cells; Colony-Forming Units Assay; Erythropoiesis; Erythropoietin; Granulocytes; Hematopoiesis; In Vitro Techniques; Liver; Mice; Oligopeptides; Pyrrolidonecarboxylic Acid