A Radioimmunoassay for the Determination of Angiotensin II in Elasmobranch Fish

• Published in: General and comparative endocrinology Vol. 111; no. 3; pp. 299 - 305
• Main Authors: Tierney, M.L., Takei, Y., Hazon, N.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-09-1998
• Subjects: Adaptation, Physiological; Analysis of Variance; Angiotensin II - blood; Animals; Cross Reactions; Dogfish - blood; Female; Logistic Models; Male; Radioimmunoassay; Reproducibility of Results
• ISSN: 0016-6480; 1095-6840
• DOI: 10.1006/gcen.1998.7114

A homologous radioimmunoassay was developed to determine the concentration of angiotensin II (Asn1, Pro3, Ile5)-Ang II) in elasmobranchs. Cross-reactivity with elasmobranch angiotensin I and other heterologous angiotensins was high and therefore all potentially cross-reacting angiotensins were separated by high performance liquid chromatography after prior extraction with Sep-Pak C18 cartridges. The validity of the assay for the determination of elasmobranch Ang II was demonstrated by parallelism with a series of Ang II standards with serially diluted elasmobranch plasma extracts. Overall recovery of elasmobranch Ang II added to a plasma pool was 75.1 ± 5.2%. Plasma Ang II concentrations measured by our RIA were similar in fish adapted to 70, 100, or 120% SW at 139 ± 20.1, 109 ± 15.3, and 119 ± 16.3 fmol·ml−1, respectively.