Department of Pharmacology, Faculty of Pharmacy, University of Al-Fateh, Tripoli, S.P.L.A.J.
Garyounis Medical Journal Vol. 5, No.1. January 1982:11-17
Two days after bleeding, the mitotic activity in the bone marrow and the thymus was increased. Associated with this increase in cell division was a significant hypercalcaemia. This persisted until the haematocrit returned to normal. These responses were mediated by the parathyroid glands which are essentialfor the normal rapid restoration of red cell proportions after haemorrhage.
However, in the phenylhydrazine treated rats, it took longer for the haematocrit to return to normal although initially it was not as low as the bled rats. The mitotic activity was increased in the bone marrow but not in the thymus and hypercalcaemia was not significant.
After haemorrhage, the dual effects of erythropoietin and calcium combine rapidly to re-establish red blood cell numbers but in the case of phenylhydrazine administration, there was no attendant calcium increase and presumably bone marrow is the only recipient of erythropoietin stimulation hence, recovery is less rapid.
Keywords: Role of Calcium Homeostatic System in Response to Bleeding and Phenylhydrazine administration