The Role of Dimethoate and UV-B on Skin of Wistar Rats.
BACKGROUND/AIM
The pesticide dimethoate (O-dimethyl-S- Nmethylcarbamoylmethyl phosphorodithioate) is able to induce severe acute toxicity in living organisms. The aim of this study was to evaluate the effects of ultraviolet radiation, alone or combined with exposure to dimethoate, on the rat skin.


MATERIALS AND METHODS
A total of 38 Wistar female rats (Rattus norvegicus albinus), were distributed into four groups: A (n=9) control group, B (n=10) exposed to ultraviolet-B radiation (UV-B), C (n=10) exposed to UV-B followed by application of dimethoate (UV-B+AGRO) and group D (n=9) exposed to dimethoate (AGRO). Histological examination of the tissues, as well as immunohistochemistry for cleaved caspase 3, Ki-67 and COX-2 expression were performed to all groups.


RESULTS
Animals submitted to UV-B exhibited hyperkeratosis with moderate cell atypia. Regarding exposure to UV-B+AGRO, the animals presented hyperkeratosis and atrophy, whereas in animals exposed to AGRO, only atrophy was noticed. The immunohistochemical results on skin revealed that UVB, AGRO and UVB+AGRO decreased cleaved caspase 3 and Ki-67 expression when compared to the control group (p<0.05). COX-2 expression decreased to UVB or AGRO groups compared to controls (p<0.05).


CONCLUSION
UV-B or AGRO exposure is able to induce histopathological changes and altered expression of cleaved caspase-3 and Ki-67 in rat skin, thus being categorized as a risk condition for skin carcinogenesis.
['DE Oliveira Fernandes|Tania Rita Moreno|TRM|', 'Oshima|Celina Tizuko Fujiyama|CTF|', 'Cardili|Leonardo|L|', 'Ribeiro|Daniel Araki|DA|', 'Silva|Marcelo Souza|MS|', 'Korinfsky|Juliana Pedrosa|JP|', 'Plapler|Hélio|H|']
D000818:Animals D017209:Apoptosis D015415:Biomarkers D049109:Cell Proliferation D004117:Dimethoate D005260:Female D007150:Immunohistochemistry D051381:Rats D017208:Rats, Wistar D012867:Skin D014466:Ultraviolet Rays
Dimethoate UV-B skin rat pesticide apoptosis cell proliferation