Degradation of Bradykinin, a Cardioprotective Substance, during a Single Passage through Isolated Rat-Heart

  • Ahmad M. (Department of Physiology and Pharmacology, University of Strathclyde) ;
  • Zeitlin I.J. (Department of Physiology and Pharmacology, University of Strathclyde) ;
  • Parratt J.R. (Department of Physiology and Pharmacology, University of Strathclyde) ;
  • Pitt A.R. (Department of Pure and Applied Chemistry, University of Strathclyde)
  • Published : 2006.03.01

Abstract

Angiotensin converting enzyme (ACE) inhibitors have cardioprotective effects in different species including human. This cardioprotective effect is mainly due to the inhibition of bradykinin (BK) degradation rather than inhibition of the conversion of angiotensin I to angiotensir. II. Bradykinin, a nonapeptide, has been considered to be the potential target for various enzymes including ACE, neutral endopeptidase 24.11, carboxypeptidase M, carboxypeptidase N, proline aminopeptidase, endopeptidase 24.15, and meprin. In the present study, the coronary vascular beds of Sprague Dawley rat isolated hearts were perfused (single passage) with Krebs solution alone or with different concentrations of BK i.e. $2.75{\times}10^{-10},\;10^{-7},\;10^{-6}\;and\;10^{-5}M$ solution. Percent degradation of BK was determined by radioimmunoassay. The degradation products of BK after passing through the isolated rat-hearts were determined using RP-HPLC and mass spectroscopy. All the four doses of BK significantly decreased the perfusion pressure during their passage through the hearts. The percentage degradation of all four doses was decreased as the concentration of drug was increased, implying saturation of a fixed number of active sites involved in BK degradation. Bradykinin during a single passage through the hearts degraded to give [1-7]-BK as the major metabolite, and [1-8]-BK as a minor metabolite, detected on HPLC. Mass spectroscopy not only confirmed the presence of these two metabolites but also detected traces of [1-5]-BK and arginine. These findings showed that primarily ACE is the major cardiac enzyme involved in the degradation of bradykinin during a single passage through the coronary vascular of bed the healthy rat heart, while carboxypeptidase M may have a minor role.

Keywords

References

  1. Ahmad, M., Zeitlin, I. J., and Parratt, J. R., The release of kininase from rat isolated hearts during myocardial ischaemia. Immunopharmacol., 33, 299-300 (1996) https://doi.org/10.1016/0162-3109(96)00047-1
  2. Bhoola, K. D., Figueroa, C. D., and Worthy, K., Bioregulation of kinins, kallikrein, kininogens, and kininases. Pharmacol. Rev., 44(1), 1-80 (1992)
  3. Campbell, J. D., Anastasopoulos, F., Duncan, M. A., James, M. G., Kladis, A., and Briscoe, A. T., Effects of neutral endopeptidase inhibition and combined angiotensin converting enzyme and neutral endopeptidase inhibition on angiotensin and bradykinin peptides in rats. J. Pharmacol. Exper. Therapeut., 287(2), 567-577 (1998)
  4. Dendorfer, A., Wolfrum, S., Wellhoner, P., Korsman, K., and Dominaik, P., Intravascular and interstitial degradation of bradykinin in isolated rat heart. Br. J. Pharmacol., 122, 1179- 1187 (1997) https://doi.org/10.1038/sj.bjp.0701501
  5. Dumoulin, J. M., Adam, A., Rouleau, L. J., and Lamontagne, D., Comparison of a vasopeptidase inhibitor with neutral endopeptidase and angiotensin-converting enzyme inhibitors on bradykinin metabolism in the rat coronary bed. J. Cardiovasc. Pharmacol., 37, 359-366 (2001) https://doi.org/10.1097/00005344-200104000-00002
  6. Erdos, E. G., Some old and some new ideas on kinin metabolism. J. Cardiovasc. Pharmacol.,15(Suppl. 6), S20- S24 (1990) https://doi.org/10.1097/00005344-199015061-00005
  7. Ersahin, C. and Simmons, W. H., Inhibition of both aminopeptidase P and angiotensin-converting enzyme prevents bradykinin degradation in the rat coronary circulation. J. Cardiovasc. Pharmacol., 30, 96-101 (1997) https://doi.org/10.1097/00005344-199707000-00014
  8. Fenn, J. B., Mann, M., Meng, C. K., Wong, S. F., and Whitehouse, E., Electrospray ionization for mass spectrometry of large biomolecules. Science, 249, 64-71 (1989) https://doi.org/10.1126/science.2164259
  9. Lamontagne, D., Nadeau, R., and Adam, A., Effect of enlaprilat on bradykinin and des-Arg9-bradykinin release following reperfusion of the ischaemic rat heart. Br. J. Pharmacol., 115, 476-478 (1995) https://doi.org/10.1111/j.1476-5381.1995.tb16357.x
  10. Linz, W., Wiemer, G., Gholke, P., Unger, T., and Scholkens, B., A. Contribution of kinins to the cardiovascular actions of angiotensin-converting enzyme inhibitors. Pharmacol. Rev., 47, 25-49 (1995)
  11. Moshi, M. J., Zeitlin, I. J., Wainwright, C. L., and Parratt, J. R., Acid Optimum kininogenase in canine myocardium and aorta. J. Cardiovasc. Res., 26, 367-370 (1992) https://doi.org/10.1093/cvr/26.4.367
  12. Piedimonte, G., Nadel, J. A., Long, C. S., and Hoffman, J. I. E., Neutral Endopeptidase in the heart: Neutral endopeptidase inhibition prevents isoproterenol-induced myocardial hypoperfusion in rats by reducing bradykinin degradation. Cir. Res., 75, 770-779 (1994) https://doi.org/10.1161/01.RES.75.4.770
  13. Raut, R., Rouleau, L. J., and Blais, C., Bradykinin metabolism in the postinfarcted rat heart: Role of ACE and neutral endopeptidase 24.11. Am. J. Physiol., 276 (Heart Circ. Physiol. 45), H1769-H1779 (1999)
  14. Shrimpton, C. N., Smith, A. I., and Lew, R. A., Soluble metalloendopeptidases and neuroendocrine signaling. Endo. Rev., 23(5), 647-664 (2002) https://doi.org/10.1210/er.2001-0032
  15. Skidgel, R. A., Bradykinin-degrading enzymes: Structure, Function, Distribution, and potential roles in cardiovascular pharmacology. J. Cardiovasc. Pharmacol., 20(Suppl. 9), S4- S9 (1992) https://doi.org/10.1097/00005344-199200209-00003
  16. Skidgel, R. A., Davis, R. M., and Tan, F., Human carboxypeptidase M. J. Biol. Chem., 264(4), 2236-2241 (1989)
  17. Yamada, H., Fabris, B., Allen, A. M., Jackson, B., Johnston, C. I., and Mendelson, A. O., Localization of angiotensin converting enzyme in rat heart. Cir. Res., 68, 141-149 (1991) https://doi.org/10.1161/01.RES.68.1.141