Haemopoietic regeneration after autohaemotransplant in sublethal X-irradiated marbled electric rays.

Haemopoiesis of Elasmobranchs provides a useful model for haematopoietic studies owing to the compartmentalisation of various maturative lineages in spleen (erythropoiesis and lymphocytopoiesis), oesophageal wall and epigonal tissue (myelopoiesis and lymphocytopoiesis). The survival capacity and the recovery of peripheral blood cells and haemopoietic organs were studied in Torpedo marmorata Risso subjected to different single doses of total-body X-ray and following autologous haemotransplantation. Torpedoes were found to be very radioresistant animals from the high dose (100 Gy) of X-ray able to produce complete destruction of haematopoietic tissues but no immediate lethality. Here we report a successful autologous peripheral blood transplantation following 100 Gy X-ray that produces death of the control torpedoes from failure of haemopoiesis. The recovery of the circulating red blood cells after autohaemotransfusion was completed in 28 days, whereas that of the white cells was slower. On day 28 after autohaemotransplant the animals displayed recovery of the haemopoietic tissues, as demonstrated by the BUdR method, but irradiated controls displayed no blood cell or haemopoietic regeneration.