Radioimmunoassay of Circulating Blood Kinin Levels
Previous estimates of the level of circulating kinins in man have ranged widely from undetectable, (1) to a mean level of about a quarter of a ng/ml (2) to levels in the μg/ml (3) range. Some workers have questioned that there is a normal level of circulating kinin and view the small amounts found as being artefacts produced by activation of plasma kininogenase during collection. Another view is that kinins are produced extravascularly and that blood levels are likely to be irrelevant to normal or abnormal function except in such rare situations as the carcinoid syndrome in which kallikrein is released by the tumour masses and produces kinins in the blood itself. Certainly the central role of tissues and particularly the lung, (4) in clearance argues against the arterial blood kinin level being of great functional significance. Nevertheless, a reliable method of measuring blood levels would be welcome since they may give an indication, admittedly considerably damped, of what was proceeding in the tissues whence the blood drained.
KeywordsCarcinoid Syndrome Coated Charcoal Blood sampIes Human Gamma Globulin Measure Blood Level
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- 1.Abe, K., Watanabe, N., Kumagai, N., Mouri, T., Seki, T., and Yoshinaga, K. Estimation of kinin in peripheral blood in man. Tohoku J. exp. Med. 89, 103–112.Google Scholar
- 2.Zacest, R., and Mashford, M.L. (1967) Blood bradykinin levels in the human. Aust. J. exp. Biol. med. Sci. 45, 89–95.Google Scholar
- 3.Zeitlin, I.J. and Smith, A.W. (1966) 5-Hydroxyindoles and kinins in the carcinoid and dumping syndrome. Lancet 2. 986–991.Google Scholar
- 4.Ferreira, S.H., and Vane, J.R. (1967) The disappearance of bradykinin and eledoisin in the circulation and vascular beds of the cat. Br. J. Pharmac. 30, 417–424.Google Scholar
- 5.Mashford, M.L., and Roberts, M.L. (1971) Determination of human urinary kinin levels by radio-immunoassay using a tyrosine analogue of bradykinin. Biochem. Pharmacol. 20, 969–973.Google Scholar
- 6.Greene, L.J., Stewart, J.M. and Ferreira, S.H. (1970) Bradykinin–potentiating peptides from the venom of Bothrops jararaca. In Bradykinin and Related Kinins, eds. Sicuteri, F., Rocha e Silva, M., and Back, N. Plenum Press, New York. pp. 81–87.Google Scholar
- 7.Herbert, V., Lau, K.S., Gottlieb, C.W., and Bleicher, S.J. (1965) Coated charcoal immunoassay of insulin. J. clin. Endocr. 25, 1375–1384.Google Scholar