Fluorescence lifetime measurements of NADH and tryptophan in the ischemic, intact rabbit myocardium

A. Hamburger, Z. Gryczynski, J. Lakowicz, K. E. Sommers

Research output: Contribution to journalConference articlepeer-review


Background: Ischemia-reperfusion injury is the leading cause of early dysfunction following transplantation. Currently, there are no techniques available to accurately measure ischemic changes during organ storage. Therefore, the interest exists in developing non-invasive monitoring techniques. We used NADH and tryptophan as fluorescent markers, since both are intrinsic fluorophores and excellent indicators for levels of hypoxia and protein denaturation, respectively. Experimental Design: We used cavity-dumped dye lasers to perform time-resolved fluorescence measurements of ischemic, intact rabbit myocardium, in order to examine whether this method would provide sufficient signal in a pilot study. Results: Multi-component decays were measured for time-resolved fluorescence changes in both NADH and tryptophan over the course of 3 hours. NADH showed a general increase in mean-lifetime, while the majority of the unbound form decreased from 0.4 to 0.28 ns. Tryptophan had a slight mean-lifetime decrease from 4 to 3.8 ns. Conclusions: Strong signals were obtained with easily resolved component lifetimes. Future studies will attempt to elaborate the correlation between organ viability and fluorescence-based signals using lifetime analyses, anisotropy studies and the application of two-photon excitation measurements.

Original languageEnglish
Pages (from-to)201-206
Number of pages6
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 1999
EventProceedings of the 1999 Biomedical Imaging: Reporters, Dyes, and Instrumentation - San Jose, CA, USA
Duration: 26 Jan 199928 Jan 1999


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