This award will support a research collaboration between Professor Fletcher of East Carolina University and Professor Lourival D. Possani of the Universidad Nacional Autonoma de Mexico in Mexico City. The investigators intend to specifically identify the receptor proteins in mammalian pancreas that are targeted by scorpion venom toxic proteins to activate exocrine secretory discharge. Identification will measure venom protein binding and localize the receptors at the cellular level. The work is expected to lead to the isolation and characterization of these receptors. The U.S. laboratory will supply the Mexican laboratory with biotinylated and radiolabled scorpion venom proteins while the Mexican laboratory will provide synthetic peptide analogs of the venom proteins. Both laboratories will use scorpion venom supplied by the Buntanton Institute in Brazil. Interest in exploring these venoms and their effect on the pancreas is high because they share no features in common with proteins and peptides previously described that are also known to act on the exocrine pancreas. These studies seem to include that certain excitatory behavior, usually associated with nerve and muscle cells, may also occur in epithelial tissue and thus may increase our understanding of receptor-mediated secretory activity of these tissues.