The spleen accumulates advanced glycation end products in the chicken: tissue comparison made with rat

Glycation starts from nonenzymatic amino-carbonyl reaction that binds carbonyl group of reducing sugars to the amino group of amino acids. Glycation leads to further complex reactions to form advanced glycation end products (AGE). Because AGE are implicated in the gradual development of diabetic complications, tissue accumulation of AGE has been widely examined in various tissues of rats. Avian species are known to have high body temperature and blood glucose concentration compared with mammals. Although these characteristics enabled chickens to be used as experimental models for diabetes mellitus, the information of AGE accumulation in various tissues of chickens has not been limited so far. In the present study, therefore, the radioactive AGE prepared by reacting (14)C-glucose and amino acids were intravenously administrated, and comparison of tissue accumulation of (14)C-labeled AGE was made between chickens and rats. At 30 min after administration, tissues (18-20) were collected, and the radioactivity incorporated into tissues was determined. High levels of radioactivity per gram of tissue in the liver and kidney were observed in both rats and chickens. In chickens but not rats, a large amount of (14)C-labeled AGE incorporated into 1 g of spleen was observed, and the specific accumulation of AGE in the avian spleen might have a particular role in immune response in avian species.