Cutaneous changes in rats induced by chronic skin exposure to ultraviolet radiation and organophosphate pesticide.
OBJECTIVE
To study the possible potentiation of the carcinogenic effects of ultraviolet radiation associated with an organophosphate pesticide.


METHODS
Forty Wistar rats were assigned into four groups (n=10 each) randomized according to the procedures: group A received only UVR-B radiation; group B, UVR-B for eight weeks followed by a seven week period of pesticide exposure; group C, UVR-B + pesticide concomitantly: group D, only pesticide application. At the end of the fifth, tenth and fifteenth weeks the animals were photographed. Skin biopsy and histopathological study with Hematoxylin-Eosin were done on the fifteenth week. Statistical analysis with Fisher's and Sign (unilateral) tests, 5% value for significance.


RESULTS
Macroscopic lesions in the group A evolved from the erythema to erythema + desquamation. The groups B and C, with the association of two carcinogens, and group D presented evolution to keratosis, with higher incidence in group D. The histology showed a significant increase in the severity of injuries when the UVR-B and the pesticide were applied simultaneously, leading to cellular atypia.


CONCLUSIONS
Concurrent association of UVR-B to organophosphate pesticide produced more severe lesions microscopically, although this has not been so apparent macroscopically. In daily practice the clinical evaluation should be complemented with laboratory evaluation.
Federal University of Sao Francisco Valley, Department of Medicine, PetrolinaPE, Brazil.
Tania Rita Moreno de Oliveira
TR
Fernandes
Federal University of Sao Francisco Valley, Department of Medicine, PetrolinaPE, Brazil.
Itamar
I
Santos
UNIVASF, Nursing Department, PetrolinaPE, Brazil.
Juliana Pedrosa
JP
Korinsfky
Federal University of Sao Francisco Valley, Department of Medicine, PetrolinaPE, Brazil.
Benedyto Sávio
BS
Lima e Silva
Oswaldo Cruz Institute Foundation, Histology Division, Rio de JaneiroRJ, Brazil.
Luis Otávio
LO
Carvalho
Sao Paulo Federal University, Paulista Medical School, Department of Surgery, Brazil.
Hélio
H
Plapler
D000818:Animals; D003043:Cocarcinogenesis; D005500:Follow-Up Studies; D008297:Male; D010755:Organophosphates / Q000633:toxicity*; D010575:Pesticides / Q000633:toxicity*; D011829:Radiation Dosage; D011833:Radiation Injuries, Experimental / Q000209:etiology / Q000473:pathology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000187:drug effects* / Q000473:pathology / Q000528:radiation effects*; D012878:Skin Neoplasms / Q000139:chemically induced / Q000150:complications / Q000473:pathology*; D014466:Ultraviolet Rays / Q000009:adverse effects*
D010755:Organophosphates; D010575:Pesticides