title: Pituitary extract of the ricefield eel Monopterus albus (Synbranchidae, Teleostei) exhibits gonadotropic activity in the classes Mammalia, Aves, Reptilia and Amphibia.
abstract: Pituitary extract of the ricefield eel Monopterus albus demonstrated gonadotropic activity in mammals and non-mammalian vertebrates. Using the rat as the recipient, FSH activity was detected in Monopterus pituitaries in the HCG augmentation test and LH activity in the ovarian ascorbic acid depletion test. Cyclic AMP level in superovulated ovaries, ovarian lactate production and glucose uptake in vitro, plasma testosterone level in males, testicular enzymes, ventral prostate weight and other androgen-dependent parameters were stimulated after treatment with Monopterus pituitary extract. Testicular and ovarian 32P5+ uptake in the chick, testicular weight in the grass turtle Chinemys reevesi, and ovulation in the amphibians Xenopus laevis and Rana tigrina were enhanced. Both the FSH-like and LH-like activities in Monopterus pituitaries were sensitive to proteolytic enzymes and chemicals that attack the disulfide linkage, carbohydrate moiety, tyrosine, tryptophan and histidine residues. This constitutes the first report of dual gonadotropic activities elicited by a teleost pituitary extract in the mammal in vivo.
authors.forename: T B
authors.initials: TB
authors.lastname: Ng
authors.forename: Y H
authors.initials: YH
authors.lastname: Lee
authors.forename: S T
authors.initials: ST
authors.lastname: Chan
mesh_terms: D000818:Animals; D001681:Biological Assay; D002645:Chickens; D002784:Cholesterol / Q000378:metabolism; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D003338:Corpus Luteum / Q000187:drug effects / Q000502:physiology; D000242:Cyclic AMP / Q000378:metabolism; D004524:Eels / Q000502:physiology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000032:analysis; D007986:Luteinizing Hormone / Q000378:metabolism*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010053:Ovary / Q000187:drug effects / Q000502:physiology; D010902:Pituitary Gland / Q000502:physiology*; D011817:Rabbits; D011898:Ranidae; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity; D013480:Superovulation; D013737:Testis / Q000187:drug effects / Q000502:physiology; D013739:Testosterone / Q000378:metabolism*; D014020:Tissue Extracts / Q000494:pharmacology*; D014426:Turtles; D014981:Xenopus
chemical_list: D006063:Chorionic Gonadotropin; D014020:Tissue Extracts; D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D002784:Cholesterol; D000242:Cyclic AMP