Experimental model of cutaneous radiation injury in rabbits

Rafael Panisi De Campos Meirelles,Rute Lellis,Americo Helene Junior,Murillo Francisco Pires Fraga,Bernardo Hochman,Lydia Masako Ferreira

doi:10.1590/s0102-86502013001100001

Abstract

To describe an experimental model of cutaneous radiation injury in rabbits. On this study eight six-month-old New Zealand male rabbits, with an average weight of 2.5 kg were used. They were distributed in four groups (n=2 per group). The control group did not receive radiotherapy and the others received one radiotherapy session of 2000, 3000 and 4500 cGy, respectively. Photographic analysis and histopathological evaluation of the irradiated areas were carried out. After 30 days, the animals from the control group had all their hair grown. In spite of that, the animals from group 2000 cGy had a 60-day alopecia and from group 3000 cGy, a 90-day alopecia. After the 30th day, the 3000 cGy group demonstrated 90-day cutaneous radiation injuries, graded 3 and 4. One of the animals from group 4500 cGy died on the 7th day with visceral necrosis. The other from the same group had total skin necrosis. A progressive reduction of glands and blood vessels count and an increase on collagen deposition was observed. The proposed experimental model is reproductable. This study suggests that the dosage 4500 cGy is excessive and the 3000 cGy is the most effective for this experimental model of cutaneous radiation injury in rabbits.

Highlights

Around 60% of cancer patients receive radiotherapy during their treatment[1,2]
There are some experimental models described for small animals[3]
There are no reproductable models in literature for medium size animals

Summary

Introduction

The most common complication of radiotherapy is the cutaneous radiation injury. The lack of experimental models of cutaneous radiation injury is one of the research challenges[3]. There are some experimental models described for small animals (murine, rats and mice)[3]. The rabbits, medium size animals, because of their immunological similarity to humans are the most frequently used for cutaneous tests such as the Draize test[4]. Their antibody development is considered resistant to radiation, differently than rats, mice and murines that aren’t capable of presenting a similar immune response[5]

Methods

Results

Conclusion