ZOU, Enmin; BONVILLAIN, Ryan; Nicholls State University; Nicholls State University: Effects of 9-cis– and all-trans-retinoic acids on blood glucose homeostasis in the fiddler crab, Uca pugilator

9-cis-Retinoic acid (9CRA) and all-trans-retinoic acid (ATRA) are known to be involved in the regulation of glucose homeostasis in vertebrates by inducing insulin release and expression of glucose transporter proteins. In view of the fact that both 9CRA and ATRA are endogenous to the fiddler crab, Uca pugilator, that a retinoid X receptor exists in this fiddler crab, and that activities of insulin-like and insulin-like growth factor-like peptides have been reported for crustaceans, we investigated whether 9CRA and ATAR also play a role in glucose homeostasis in Uca pugilator. Neither 9CRA nor ATRA was found to produce hypoglycemic effects at a dose of 10 &#956g/g live mass. However, 9CRA, but not ATRA, induced hyperglycemia. Such 9CRA-induced hyperglycemia was apparently mediated by the eyestalk hormone CHH since injection of 9CRA into eyestalk-ablated crabs did not result in hyperglycemia. ATRA was found to have an inhibitory effect on the return of blood glucose concentration to the baseline level initially following ATRA administration.