9418819 Conlon In mammals, including the human, specific enzymes (kallikreins) cleave a circulating protein (kininogen) to generate a small peptide (bradykinin) that is involved in regulating blood flow and both neuronal and smooth muscle activity. This process is referred to as the kallikrein-kinin system but it is not known when the system arose in evolution or whether it plays an important functional role in non-mammalian vertebrates. Dr. Conlon proposes to examine plasma samples from a wide range of aquatic vertebrates at different levels of evolution for the presence of the components of the system. He has already purified novel bradykinin-related peptides from the trout and from the phylogentically ancient fish, the bowfin, and he proposes to systematically investigate the biological activities of the peptides in their species of origin. Dr. Conlon will study effects on cardiovascular parameters using chronically cannulated animals and identify target sites for the peptides using isolated tissue preparations. The data will permit an assessment of the physiological importance of the kallikrein-kinin system in fish. ***
