Presence and distribution of radioimmunoassayable LHRH in the European eel, Anguilla anguilla.
Eel brain contains a factor which exhibited a complete cross-reaction in a radioimmunoassay (RIA) for mammalian luteinizing hormone-releasing hormone (LHRH) and which exhibited a behavior similar to that of synthetic mammalian LHRH on Sephadex G-25. Eel brains contained 920 +/- 135 pg of this LHRH-like immunoreactive factor (IR-LHRH); 75% of immunoreactivity was present in the di- and mes-encephalon, 21% in the telencephalon and 4% in the hind-brain. Thus, IR-LHRH in eel brain exhibited a much wider distribution than in mammalian brain. Pituitary also contained a large amount of IR-LHRH (304 +/- 69 pg) at a concentration even higher than in median hypothalamic lobe; this result is probably related to the fact that, in teleost, median eminence is included into the pituitary. An immunoreactive substance was also present in the blood. In conclusion, the lack of sexual development and the low gonadotropic function in the eel, are apparently not related to an absence of LHRH.
D000811:Anguilla / Q000502:physiology*; D000818:Animals; D001923:Brain Chemistry; D002850:Chromatography, Gel; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000032:analysis* / Q000097:blood; D010902:Pituitary Gland / Q000032:analysis; D011863:Radioimmunoassay / Q000379:methods; D014018:Tissue Distribution
D007987:Gonadotropin-Releasing Hormone