Urotensin I- and CRF-like peptides in Catostomus commersoni brain and pituitary--HPLC and RIA characterization.
Two distinct neuronal systems, containing urotensin I-like immunoreactivity (UI-LI) and CRF-LI respectively, have previously been demonstrated immunocytochemically in the brain and pituitary of the teleost Catostomus commersoni. In the present studies, we used HPLC followed by UI- and CRF-RIA to further characterize these UI- and CRF-LI substances. HPLC of Catostomus brain extracts (including extracts modified by dilute H2O2 oxidation or dilute acid cleavage) suggests that the major form of brain UI-LI is very likely identical to the previously characterized urophysial UI; the small amount of pituitary UI-LI is not yet fully characterized. The behavior of brain CRF-LI on reversed phase (RP) extraction suggests that it may exist largely in precursor form. Pituitary CRF-LI, however, behaved as expected for a peptide on RP extraction, and eluted from HPLC as essentially a single (though somewhat broad) peak. The HPLC behavior of pituitary CRF-LI, and its crossreactivity with various CRF antisera, suggest that it represents authentic fish CRF, apparently similar to (but not identical with) human/rat CRF.
McMaster
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D
Department of Pharmacology and Therapeutics, University of Calgary, Faculty of Medicine, Alberta, Canada.
Lederis
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K
D000818:Animals; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid; D003346:Corticotropin-Releasing Hormone / Q000032:analysis*; D003429:Cross Reactions; D003531:Cypriniformes / Q000378:metabolism*; D009928:Organ Specificity; D010455:Peptides / Q000032:analysis*; D010902:Pituitary Gland / Q000032:analysis*; D011863:Radioimmunoassay / Q000379:methods; D014579:Urotensins / Q000032:analysis*
D010455:Peptides; D014579:Urotensins; D003346:Corticotropin-Releasing Hormone; C029676:urotensin I