الفهرس 
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Abstract
The renal RAS plays an important role in the body fluid homeostasis. All major components and key enzymes for the establishment of a local RAS have been confirmed in the kidney. In addition to renal contribution to the systemic RAS, the intrarenal RAS plays a critical role in the regulation of renal function as well as in the development of kidney disease. Interruption of the RAS with an ACEI or ARB slows the progression of chronic renal insufficiency.
Use of ACEI and ARB was associated with a significant improvement in renal outcome. Animal venom mostly contains characteristically small bioactive peptides. One of these components has been isolated from the Egyptian scorpions and snakes. It was referred to as BPF acting as an ACEI. It induces several physiological effects and stimulates liver and kidney functions.
In an attempt to clarify if this bioactive isolated venom fraction can improve kidney functions post-irradiation in comparison with ARB (losartan), detection of RBCs, WBCs, Hb, Hct, GSH, MDA, AOPP, aldosterone, sodium, potassium, chloride, calcium, urea, createnine and uric acid were investigated.
BPF was isolated from venom of scorpion, Androctonus amoreuxi. Groups of 10 white rats (70 - 80 gm each) were used in the present experiment. Animals were categorized into:
• A normal control group. The rats were sacrificed after 21 days of the beginning of the test.
• A group of rats received an intra-peritoneal (i.p.) injection of BPF (1μg / g body wt) twice per week for three weeks and sacrificed after 21 days.
• A group of rats received i.p. injection of losartan (5μg / g body wt) twice per week for three weeks and sacrificed after 21 days.
• A group of rats irradiated with 4 Gy gamma rays and sacrificed after 21 days.
• A group of rats irradiated with 4 Gy gamma rays and received i.p. injection of BPF (1μg / g body wt) twice per week for three weeks and sacrificed after 21 days.
• A group of rats irradiated with 4 Gy gamma rays and received i.p. injection of losartan (5μg / g body wt) twice per week for three weeks and sacrificed after 21 days.
After 21 days from the beginning of experiment, rats were sacrificed, blood and kidney samples were collected. RBCs and WBCs were counted, Hb and Hct were detected, GSH, MDA and AOPP were measured in kidney, aldosterone, sodium, potassium, chloride, calcium, urea, createnine and uric acid levels were detected in serum.
The results pointed out that the repeated injections of BPF (1µg/1g body wt) in normal rats in the present investigation showed significant elevation in the level of K+ with significant DROP in the level of Na+ and uric acid.
Similarly repeated injections of losartan (5µg/1g body wt) showed significant DROP in the level of Na+ and uric acid compared to control.
Gamma irradiation at 4 Gy revealed a significant elevation (P<0.05) in the level of MDA, AOPP, aldosterone, sodium, urea and creatinine. However, it induced a significant DROP in the haematological parameters (RBCs, WBCs, Hb and Hct), GSH, calcium and uric acid compared to the control.
Losartan treatment of irradiated rats recorded a significant elevation (P<0.05) in RBCs, WBCs, Hb, Hct and GSH compared to those of irradiated group. A significant elevation was noticed in WBCs and GSH level with the use of BPF after irradiation.
A significant decrease in MDA, aldosteron, urea, creatinine and uric acid compared to that of irradiated group was observed in the groups that were irradiated and treated with BPF or irradiated and treated with losartan.
Animal group that received whole body gamma irradiation and losartan showed a significant decrease in Na+ and Cl- compared to the irradiated group.
In conclusion, ACEI and ARBs can likely improve oxidative stress induced by radiation that leads to kidney damage. Therapeutic agents from the different classes such as natural BPF or artificial as losartan, can be of parallel effect. This prospect broadens the way of curative radiation therapy.