THE EFFECTS OF ULTRAVIOLET RADIATION ON THE INNATE IMMUNE RESPONSE OF Caiman latrostris. REPORT OF ADVANCE

LUCÍA FERNANDEZ, GISELA POLETTA, PATRICIA AMAVET AND PABLO SIROSKI

Manaos, Brasil

Congreso; XX Working Meeting of the Crocodile Specialist Group (CSG/SSC/UICN); 2010

Crocodile Specialist Group

The sun emits ultraviolet radiation (RUV) that is necessary to many vital biological processes. RUV exposure is essential for development and reproduction, the synthesis of vitamin D3 one of its most important benefits. Overexposure to RUV might induce adverse biological effects such as immune suppression, which could debilitate recognition of some antigens after a few days of the irradiation. Some researches assert that the damages caused by this type of radiation might have tremendous influence on the health of populations. Although the UV-B wavelength range can exert a positive influence on diverse biological effects, excessive UVB radiation exposure interferes with the normal function of the immune system in both animals and human beings. Lipopolysaccharide (LPS) is a major component of the wall of Gram negative bacteria. LPS contains a toxic substance, Lipid A, that is recognized by the immune systems of higher eukaryotes and causes an inflammatory reaction. Twenty seven broad-snouted caiman (3 months old) will be used for this study. Eggs will be harvested from 3 different wild nests and artificially incubated under controlled conditions. Caiman will be maintained under different UVR intensities during the 60 days. The UV exposure will be of 12 hours per day. For each treatment group, we will evaluate animal growth (weight, total length and snout – vent length), as well as immune system function by total and differential peripheral leukocytes counts, serum complement activity and total and fractional concentrations of serum proteins. We suspect that overexposure to RUV will lead to an immunesuppressive effect, reducing the immune response of Caiman latirostris due to E. coli LPS.