Meeting Abstract

P2.14  Tuesday, Jan. 5  Effects of nitrate exposure on pancreatic beta-cells in American alligator HARTY, J.H.*; FREYMILLER, H.J.; EDWARDS, T.M.; GUILLETTE, L.J.; Univ. of Florida, Gainesville; Univ. of Florida, Gainesville; Tulane University, New Orleans; Univ. of Florida, Gainesville jharty@ufl.edu

During the past fifty years, humans have produced and released a surfeit of reactive nitrogen into the environment. Now, few parts of the Earth are unimpacted by nitrogen pollution. Nitrate infiltrates surface and groundwater, potentially contaminating drinking water sources. It is suspected that over 20% of groundwater sources exceed the US and World Health Organization limits of 10 mg/L nitrate-nitrogen (NO3-N). Thus, it is now important to understand the health consequences of excess nitrate exposure. Recent evidence suggests that type 1 diabetes (T1D) may be caused by dietary nitrates, nitrites, and N-nitroso compounds. Type 1 diabetes is an autoimmune disease in which lymphocytes attack beta cells. This reduces beta cell number and area and leads to low insulin production. We tested the effect of environmentally relevant nitrate exposure on the area and number of insulin-producing beta cells in the pancreas of Alligator mississippiensis. Alligator eggs were collected from Lake Woodruff, Florida, in June 2008. After hatch, the animals were exposed for five months to environmentally relevant concentrations of nitrate (10 or 100 mg/L NO3-N) in their tank water or a tap water control (n = 15 animals per treatment). If there is a connection between nitrate exposure and diabetes, we would expect a decreased number and/or area of beta cells in the pancreas of the alligators exposed to nitrate. Our discussion will focus on the impact of nitrate as an environmental contaminant and its effect on beta cells in the pancreas of the American alligator.