ABSTRACT
The present work was conducted to investigate the histological, and ultra-structural changes that occurred in the kidney tissues of albino rats due exposure to gamma- radiation. Also we investigated how to protect the tissues from the damaging effects of gamma radiation using a natural product such as Beta-carotene. Thirty four male albino rats were divided into four main groups; the first group served as control (5 rats). Rats of the second group (5 rats) ) received 5mg/kg body wt. of β-carotene at a daily oral dose for 2 consecutive weeks .The rats of the third main group (12 rats) were exposed to a sub-lethal dose (6Gy) of whole body γ-irradiation and then divided into four equal subgroups. Rats of the fourth main group (12 rats) received β-carotene before being exposed to gamma radiation and then divided into four equal subgroups. Treated rats were autopsied at four intervals; one day, one week, two weeks and four weeks post irradiation. The histological studies of the groups that exposed to gamma radiation revealed progressive pathological lesions as represented by severe damage in glomerular tuft with wide Bowman's space and severe hemorrhagic areas scattered in between degenerated renal tissues, increase in mesangial cells and renal tubules which suffered various degrees of degeneration. The ultra-structural studies revealed that epithelial cells lining the proximal and distal convoluted tubules showed an increase in the swollen mitochondria , dilation in the rough endoplasmic reticulum and electron dense in the nuclear chromatin. Thickness in basement membrane and dilation of infolded were observed. Damage of brush boarder and collagen fibers was also observed. The treatment with β-carotene (5mg/kg b. wt. for two consecutive weeks) pre-exposure to gamma radiation attenuated most of these changes. Therefore, the present study has implication for the potential use of β-carotene as a radioprotector.