Functional visualization of the excretory system of adult Schistosoma mansoni by the fluorescent marker resorufin.
Excretion of metabolic wastes as well as xenobiotics is a major concern of all living organisms, and the Platyhelminthes including Schistosoma mansoni possess the protonephridial excretory system for their survival. Except for some ultra-structural and biochemical information, little is known about the protonephridium of platyhelminths due to a lack of established techniques for exploring the excretory activity. This study describes a new technique to assess the excretory activity of S. mansoni by use of the fluorescent marker resorufin, which is a potential substrate of the drug efflux pump, P-glycoprotein. After simple diffusion into the schistosome body, fluorescent resorufin was concentrated in the excretory tubules by an energy-dependent mechanism and excreted via the nephridiopore. The present technique of labelling functionally the excretory system was applicable to adult worms, but not schistosomula or cercariae. A variety of modulators known to interfere with mammalian P-glycoprotein function perturbed resorufin excretion from male adult schistosomes, including cyclosporin A, Ro11-2933, verapamil, or nifedipine. This technique of labelling the excretory system with fluorescent resorufin has enabled us to study aspects of the physiological function, hitherto unknown, of the protonephridial system of S. mansoni.
Sato
H
H
Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, West Medical Building, University of Glasgow, Glasgow G12 8QQ, Scotland. sato7dp4@cc.hirosaki-u.ac.jp
Kusel
J R
JR
Thornhill
J
J
D018435:ATP Binding Cassette Transporter, Subfamily B / Q000037:antagonists & inhibitors / Q000378:metabolism; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D005453:Fluorescence; D005456:Fluorescent Dyes; D008297:Male; D015394:Molecular Structure; D010078:Oxazines / Q000378:metabolism; D012550:Schistosoma mansoni / Q000033:anatomy & histology* / Q000187:drug effects / Q000378:metabolism*
D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005456:Fluorescent Dyes; D010078:Oxazines; C014180:resorufin; D000584:Amiloride