Restorative Capacity of Bone Marrow Transplantation in Gamma-irradiated Rats: A Study of the Bone Marrow, Spleen, Lungs and Blood

Abstract

Bone marrow transplantation (BMT) has been widely used for the treatment of autoimmune diseases, solid malignant tumours, multiple myelomas, and myelodysplastic syndrome. Allogeneic bone marrow transplantation is widely used for the treatment of various haematologic disorders. Total body irradiation (TBI) followed by bone marrow transplantation (BMT) is becoming an established modality in the treatment of malignant haematopoietic disorders. Bone marrow transplantation (BMT) is an important therapeutic option for various malignant, nonmalignant conditions, leukemias, anaemia, congenital immunodeficiencies, metabolic disorders and also autoimmune diseases and inherited disorders of haematopoiesis. In the present study male albino rats (Rattus norvegicus) ― each weighing 120 ―130 g ― were used for the different investigations carried out in this work. The animals were randomly divided into 6 groups: Group I: Comprised 6 animals; they were considered as untreated control group. Group II: Comprised 6 animals; this group was transplanted with bone marrow cells. Group III: Comprised 6 animals; this group was exposed to 3 Gy whole body gamma-radiation. Group IV: Comprised 6 animals; this group was exposed to 5 Gy whole body gamma-radiation. Group V: Comprised 6 animals; this group was exposed to 3 Gy whole body gamma-radiation, and then after 3 hr bone marrow was transplanted through the caudal vein. Group VI: Comprised 6 animals; this group was exposed to 5 Gy whole body gamma-radiation, and then after 3 hr bone marrow was transplanted through the caudal vein. All the animals were sacrificed after 5 weeks of the last irradiation dose. Blood samples were collected from each rat for measuring the following parameters:

I. The biochemical parameters 1- Malondialdehyde content in the blood plasma and liver (MDA). 2- Lactate dehydrogenase activity in the blood plasma (LDH). 3- Total reduced glutathione content in the blood plasma and liver (GSH). 4- Alkaline phosphatase level in the blood plasma (ALP).

II. The haematological parameters - Red blood cells count (RBCs). - Haemoglobin content (Hb). - Haematocrit value (HCT). - White blood cells count (WBCs) - Blood platelets count (PLT).

III. The histological studies Microscopical sections of the lungs, spleen and bone marrow were stained with: 1. Haematoxylin and Eosin for general histological studies. 2. Masson's Trichrome stain for collagen fibres. The results obtained from the present study are summarized as follows: The biochemical parameters: There were significant increases in malondialdehde (MDA) content, activity of lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) levels in the blood plasma of the animals irradiated with 3 Gy or 5 Gy. As well, the groups of irradiated rats treated with bone marrow showed significant increases in MDA, LDH and ALP as compared to the control group. However, such increases were significantly lower if compared with the corresponding irradiated group; this reflects the benefit of bone marrow transplantation. But there was a significant decrease in reduced glutathione (GSH) level in the blood plasma and the liver of the irradiated rats (3 Gy or 5 Gy). Bone marrow transplantation in the irradiated rats ameliorated the decrease of GSH as manifested when compared with the irradiated groups. However, the animals treated with bone marrow showed non-significant change in these investigated parameters. The haematological parameters: Data obtained in this study revealed that a significant decreases in RBCs, HGB, HCT, WBCs and PLT in blood occurred after exposure to 3 Gy or 5 Gy gamma-radiation as compared to the control group. The pronounced decline was in rats exposed to 5 Gy. Bone marrow transplantation restored the values of RBCs, HGB and HCT in the group received 3 Gy, while WBCs and PLT showed significant decrease if compared with the control level. On the other hand, the value of HCT in the group that received 5 Gy reached approximately to the control value, accompanied with partial amelioration in the other parameters.