title: Structural characterization and effects on corticosteroid secretion of endothelin-1 and endothelin-3 from the frog Rana ridibunda.
abstract: ABSTRACT Despite the intensive study of endothelin (ET) in mammals, the primary structure and biological activity of the peptide is not known for any species of non-mammalian tetrapod. Extracts of the stomach and the liver of the European green frog Rana ridibunda contained ET-like immunoreactivity measured by RIA using an antiserum raised against human ET-1. The amino acid sequence of the peptide that was isolated in pure form from the stomach extract was identical to that of human ET-1 and the peptide purified from the liver extract was identical to human ET-3 except for a single amino acid substitution (Phe(4)-->Tyr). These observations demonstrate that the amino acid sequences of ET family peptides have been very strongly conserved during evolution of tetrapods and suggest that the pathway of post-translational processing of preproendothelin in the frog is similar to that in mammals. Both frog/human ET-1, frog ET-3 and human ET-3 produced a concentration-dependent increase in the production of corticosteroids from perifused slices of the frog interrenal gland. The maximum responses produced by the peptides (approximately 2-fold increase over basal levels for both corticosterone and aldosterone production) were not significantly different. The potency of ET-1 (-log EC(50)=9.81+/-0.01 (s.e.m.) for corticosterone and 9.52+/-0.29 for aldosterone production) was significantly (P<0.01) greater than that of frog ET-3 (-log EC(50)=8.13+/-1.6 for corticosterone and 8.15+/-0.33 for aldosterone production) but the potencies of frog ET-3 and human ET-3 (-log EC(50)=8.29+/-0.34 and 7.87+/-0.18) were not significantly different.
authors.affiliation: Regulatory Peptide Center, Department of Biomedical Sciences, Creighton University Medical School, Omaha, Nebraska 68178-0405, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: I
authors.initials: I
authors.lastname: Remy-Jouet
authors.forename: C
authors.initials: C
authors.lastname: Delarue
authors.forename: M
authors.initials: M
authors.lastname: Letourneau
authors.forename: A
authors.initials: A
authors.lastname: Fournier
authors.forename: H
authors.initials: H
authors.lastname: Vaudry
authors.forename: J M
authors.initials: JM
authors.lastname: Conlon
mesh_terms: D000305:Adrenal Cortex Hormones / Q000096:biosynthesis*; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D019332:Endothelin-1 / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D019334:Endothelin-3 / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D007401:Interrenal Gland / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000502:physiology; D051379:Mice; D008969:Molecular Sequence Data; D011863:Radioimmunoassay; D011895:Rana ridibunda; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013270:Stomach / Q000502:physiology; D014020:Tissue Extracts / Q000737:chemistry
chemical_list: D000305:Adrenal Cortex Hormones; D019332:Endothelin-1; D019334:Endothelin-3; D014020:Tissue Extracts