Kidney radioprotection by temporary hypoxia. Experiments with degradable microspheres

Area of Science:

• Radiology
• Nephrology
• Biomedical Engineering

Background:

• Ionizing radiation poses a significant risk to biological tissues.
• Deep hypoxia is known to confer protection against radiation damage.
• Developing methods to induce localized, temporary hypoxia is crucial for targeted radioprotection.

Purpose of the Study:

• To investigate the radioprotective effect of induced deep hypoxia on kidney tissue.
• To evaluate the impact of temporary renal circulation blockage on kidney function and survival post-irradiation.
• To compare the efficacy of hypoxia-induced protection against high-voltage X-rays in rats.

Main Methods:

• Unilaterally nephrectomized rats underwent intra-arterial injection of degradable starch microspheres to induce temporary renal hypoxia.
• Kidneys were exposed to single doses of high-voltage X-rays.
• Renal function (glomerular filtration rate, Hippuran clearance, urine osmolarity) and survival rates were assessed and compared between hypoxia-protected and non-protected groups.

Main Results:

• Hypoxia-protected rats exhibited a 1.6-fold higher survival rate compared to non-protected animals.
• All non-protected animals irradiated with 42 Gy died, while protected animals survived higher doses.
• Irradiated animals, regardless of protection, showed reduced glomerular filtration rate, Hippuran clearance, and urine osmolarity compared to controls.

Conclusions:

• Temporary renal hypoxia induced by degradable starch microspheres offers significant radioprotection to the kidney against high-voltage X-rays.
• This hypoxia-mediated protection enhances survival rates and preserves renal function following radiation exposure.
• The findings support the potential of induced hypoxia as a therapeutic strategy for mitigating radiation-induced kidney injury.