title: Early cysteine protease activity in excretory bladder triggers metacercaria excystment of Paragonimus westermani.
abstract: The cysteine proteases of Paragonimus westermani metacercaria are known to initiate metacercaria excystment. However, their secretory sites, such as the intestine, tegument, and excretory bladder are not well defined. In this study, the metacercariae were labeled with bromodeoxyuridine (BrdU) to distinguish the initial activation sites. BrdU was labeled mainly at the excretory bladder and the excretory granules of the metacercariae and the newly excysted juvenile worms. This result shows that early 'defecation' of the proteases from the excretory bladder may accelerate the excystment of P. westermani metacercariae.
authors.affiliation: Department of Parasitology, College of Medicine and Institute of Medical Science, Cheju National University, Jeju, 690-756, Korea.
authors.forename: Y B
authors.initials: YB
authors.lastname: Chung
authors.forename: T S
authors.initials: TS
authors.lastname: Kim
authors.forename: H J
authors.initials: HJ
authors.lastname: Yang
mesh_terms: D000818:Animals; D003400:Astacoidea / Q000469:parasitology; D001973:Bromodeoxyuridine; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D048492:Paragonimus westermani / Q000201:enzymology* / Q000502:physiology; D013194:Staining and Labeling; D001743:Urinary Bladder / Q000201:enzymology
chemical_list: D003546:Cysteine Endopeptidases; D001973:Bromodeoxyuridine