Evaluation of some hormonal levels related to age in adult and aged male rats exposed to gamma radiation

As we grow older, the ability to produce most hormones in adequate amounts declined. This decline in natural hormones production coincides with nearly every age-related health problems. The present work aims to evaluate the levels of some hormones related to age namely dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEA-s) and melatonin and also the alteration in lipid fractions using male rats subjected to acute sublethal dose of gamma radiation. This study included thirty two male albino rats divided into two main groups; adult group (four months old) and aged group (20 months old). Each group was divided into two subgroups; control group and group irradiated at a dose level of 5 Gray whole body gamma irradiation. Blood samples were collected from both adult and aged groups 3 days post-irradiation after 16 hours fasting. As related to age, the aged group showed significant decrease in DHEA, DHEA-s and melatonin levels and significant increase in total cholesterol, triglycerides, LDL-c and cholesterol/HDL ratio when compared to adult group. Concerning the effect of gamma radiation, the irradiated adult group showed significant (P<0.01) decrease in DHEA, DHEA-s and melatonin levels by values equal to -32.2%, - 39.8% and -67.9%, respectively, and nonsignificant changes in lipids concentrations except for LDL-c level, which showed significant (P<0.05) increase at +58.2 % in irradiated adult group as compared to adult controls. On the other hand, exposure to irradiation of aged rats did not affect the hormonal levels assayed except for the level of DHEA-s which was decreased significantly (P<0.05) by -26.4% as compared to control aged rats. Also, total cholesterol and LDL-c levels were increased significantly (P<0.01) by +17.1% and +27.4 %, respectively in irradiated rats as compared to control aged group. It could be concluded that y-radiation obviously accelerates the aging process in adults suggesting the need for protective agents to overcome the effects of ionizing radiation in exposed individuals