Influence of phentolamine and other drugs on proliferation of hemopoietic stem cells and on postirradiation survival of Swiss mice.
The effect of combination of drugs composed of phentolamine (PHE), 5-hydroxytryptophan (5-HTP), dopamine (DA), and haloperidol (HAL), which is known to inhibit differentiation of lymphocytes [15, 16, 17] on the hemopoietic stem cells forming colonies in the spleen (CFU-S) of mice was investigated. the mixture of drugs administered for 3 consecutive days produced more then twofold increase in transplantable CFU-S content in bone marrow of donor Swiss mice. Similar effect was observed after 5-HTP or PHE administered as single drugs. The other components of the mixture appeared to be ineffective. PHE injected into the recipients of bone marrow 1 h after its transplantation reduced the percentage of CFU-S in the phase of DNA synthesis (S-phase of the cell cycle) from approx. 61 to 40%. the above result in view of the simultaneous increase in CFU-S content in bone marrow of donor mice suggests that the inhibitory effect of PHE on differentiation of CFU-S exceeds its effect on their proliferation. The increase in the mean survival time of animals irradiated with 700 and 750 R 1 h after the last injection of PHE, administered alone or in combination with drugs for 3 consecutive days, was also observed. This effect was less pronounced than might be expected from the obtained increase in CFU-S content.
D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000818:Animals; D001854:Bone Marrow Cells; D016026:Bone Marrow Transplantation; D002455:Cell Division / Q000187:drug effects; D003114:Colony-Forming Units Assay; D006412:Hematopoietic Stem Cells / Q000187:drug effects*; D008297:Male; D051379:Mice; D010646:Phentolamine / Q000494:pharmacology*; D011837:Radiation-Protective Agents
D011837:Radiation-Protective Agents; D006916:5-Hydroxytryptophan; D010646:Phentolamine