OBJECTIVES: The purpose of this study was to localize in leeches the renin-like enzyme previously characterized as well as the leech angiotensin-converting like enzyme (ACE).
METHODS: Immunocytochemical as well as whole mount experiments were performed with an antibody raised against a fragment of the leech renin-like enzyme (VLWAAEKTQLDTGSS) and with anti-leech ACE.
RESULTS: Anti-leech renin stains the vascular pole of the glomerulus and the afferent arteriole of the rat kidney. Immunostaining of leech sections revealed labeling in neurons and glial cells of the central nervous system (CNS), immunocytes and the nephridial canal, canaliculi and the periphery of the ciliated funnel, as well as the epithelium lining nephridia. Co-localization between antibodies raised against this fragment and a fragment of leech angiotensin-converting enzyme was demonstrated in neurons and glial cells of the leech CNS, as in vertebrates
MAIN FINDING: Leech renin is localized in leeches like in vertebrate in the excretory system and in the nervous system.
CONCLUSIONS: Our findings suggest the presence of a renin-angiotensin system involved in osmoregulation in leeches.