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Quantitation of myoglobin saturation in the perfused heart using myoglobin as an optical inner filter.
Am J Physiol 1994; 267(2 Pt 2):H645-53AJ

Abstract

Quantitation of metabolic parameters using the technique of cardiac surface fluorescence is complicated by motion and changes in tissue absorption. Because ratio fluorescence methodology can be applied to eliminate motion-induced errors, in the current study, we used a ratio fluorescence technique to evaluate myoglobin saturation in the perfused rat heart, since myoglobin is the major oxygen-dependent light absorbing species in this tissue. Changes in myoglobin saturation can affect surface fluorescence measurements as a result of the inner filter effect. Optical scans of heart extracts indicated the major absorption peak is due to myoglobin and its peak wavelength shifts from 415 to 430 nm upon deoxygenation. To monitor this shift in hearts, the isolated perfused heart was loaded covalently with the fluorescent dye 7-diethylaminocoumarin-3-carboxylic acid by brief perfusion with the succinimidyl ester. This dye has an excitation maximum in the region of maximal absorption by myoglobin and allows for monitoring myoglobin oxygenation using the inner filter effect. The dye localized to endothelial cells and increased the surface fluorescence in this wavelength region approximately 50-fold above background levels without affecting cardiac function. An equation was derived to estimate the fraction of myoglobin in the oxygenated state from changes in the fluorescence 415/430 excitation ratio. From this fraction, the average PO2 in the environment of myoglobin was estimated under several perfusion conditions. We report that retrograde perfusion in the Langendorff mode at either 60 or 120 mmHg pressure resulted in full oxygenation of myoglobin with use of cell-free perfusate equilibrated with 95% O2.(

ABSTRACT

TRUNCATED AT 250 WORDS)

Authors+Show Affiliations

Department of Cellular and Molecular Physiology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

8067420

Citation

Leisey, J R., et al. "Quantitation of Myoglobin Saturation in the Perfused Heart Using Myoglobin as an Optical Inner Filter." The American Journal of Physiology, vol. 267, no. 2 Pt 2, 1994, pp. H645-53.
Leisey JR, Scott DA, Grotyohann LW, et al. Quantitation of myoglobin saturation in the perfused heart using myoglobin as an optical inner filter. Am J Physiol. 1994;267(2 Pt 2):H645-53.
Leisey, J. R., Scott, D. A., Grotyohann, L. W., & Scaduto, R. C. (1994). Quantitation of myoglobin saturation in the perfused heart using myoglobin as an optical inner filter. The American Journal of Physiology, 267(2 Pt 2), pp. H645-53.
Leisey JR, et al. Quantitation of Myoglobin Saturation in the Perfused Heart Using Myoglobin as an Optical Inner Filter. Am J Physiol. 1994;267(2 Pt 2):H645-53. PubMed PMID: 8067420.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Quantitation of myoglobin saturation in the perfused heart using myoglobin as an optical inner filter. AU - Leisey,J R, AU - Scott,D A, AU - Grotyohann,L W, AU - Scaduto,R C,Jr PY - 1994/8/11/pubmed PY - 1994/8/11/medline PY - 1994/8/11/entrez SP - H645 EP - 53 JF - The American journal of physiology JO - Am. J. Physiol. VL - 267 IS - 2 Pt 2 N2 - Quantitation of metabolic parameters using the technique of cardiac surface fluorescence is complicated by motion and changes in tissue absorption. Because ratio fluorescence methodology can be applied to eliminate motion-induced errors, in the current study, we used a ratio fluorescence technique to evaluate myoglobin saturation in the perfused rat heart, since myoglobin is the major oxygen-dependent light absorbing species in this tissue. Changes in myoglobin saturation can affect surface fluorescence measurements as a result of the inner filter effect. Optical scans of heart extracts indicated the major absorption peak is due to myoglobin and its peak wavelength shifts from 415 to 430 nm upon deoxygenation. To monitor this shift in hearts, the isolated perfused heart was loaded covalently with the fluorescent dye 7-diethylaminocoumarin-3-carboxylic acid by brief perfusion with the succinimidyl ester. This dye has an excitation maximum in the region of maximal absorption by myoglobin and allows for monitoring myoglobin oxygenation using the inner filter effect. The dye localized to endothelial cells and increased the surface fluorescence in this wavelength region approximately 50-fold above background levels without affecting cardiac function. An equation was derived to estimate the fraction of myoglobin in the oxygenated state from changes in the fluorescence 415/430 excitation ratio. From this fraction, the average PO2 in the environment of myoglobin was estimated under several perfusion conditions. We report that retrograde perfusion in the Langendorff mode at either 60 or 120 mmHg pressure resulted in full oxygenation of myoglobin with use of cell-free perfusate equilibrated with 95% O2.(ABSTRACT TRUNCATED AT 250 WORDS) SN - 0002-9513 UR - https://www.unboundmedicine.com/medline/citation/8067420/Quantitation_of_myoglobin_saturation_in_the_perfused_heart_using_myoglobin_as_an_optical_inner_filter_ L2 - http://www.physiology.org/doi/full/10.1152/ajpheart.1994.267.2.H645?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -