title: Kallikrein generates angiotensin II but not bradykinin in the plasma of the urodele, Amphiuma tridactylum.
abstract: Incubation of heat-denatured plasma from the urodele, Amphiuma tridactylum (three-toed amphiuma) or from the anurans Rana ridibunda (European green frog) and Rana catesbeiana (American bullfrog) with either glass beads, porcine pancreatic kallikrein or trypsin did not generate bradykinin-like immunoreactivity. However, peptides were generated in kallikrein-treated amphiuma plasma that contracted vascular rings from the bullfrog systemic arch and had a spasmogenic action on the bullfrog urinary bladder. These peptides which were not generated in trypsin-treated plasma, were purified to homogeneity by reverse-phase HPLC and their primary structures established as: Asp-Arg-Val-Tyr-Val-His-Pro-Phe ([Asp1,Val5]angiotensin II) and Asn-Arg-Val-Tyr-Val-His-Pro-Phe ([Asn1,Val5]angiotensin II). Incubation of synthetic [Asn1,Val5]angiotensin II with amphiuma plasma resulted in deamidation to [Asp1,Val5]angiotensin II. The data suggest, therefore that amphiuma plasma contains an L-asparagine amidohydrolase (asparaginase), as previously described for the eel. Although bradykinin-related peptides have been isolated from frog skin, this study provides evidence tha the kallikrein-kinin system may be absent from the blood of amphibia.
authors.affiliation: Department of Biomedical Sciences, Creighton University Medical School, Omaha, NE 68178, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Conlon
authors.forename: K
authors.initials: K
authors.lastname: Yano
mesh_terms: D000595:Amino Acid Sequence; D000804:Angiotensin II / Q000097:blood* / Q000737:chemistry; D000818:Animals; D001920:Bradykinin / Q000097:blood*; D002417:Cattle; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005898:Glass; D007610:Kallikreins / Q000494:pharmacology*; D008297:Male; D008863:Microspheres; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D011892:Rana catesbeiana / Q000097:blood; D011895:Rana ridibunda / Q000097:blood; D013552:Swine; D014357:Trypsin / Q000494:pharmacology; D001743:Urinary Bladder; D014562:Caudata / Q000097:blood*
chemical_list: D000804:Angiotensin II; D007610:Kallikreins; D014357:Trypsin; D001920:Bradykinin