Date of Award

2011

Degree Type

Thesis

Degree Name

Master of Science in Biomedical Sciences

First Advisor

Vance G. Nielsen, MD

Second Advisor

Ruth D. Thornton, PhD

Third Advisor

S. Nini Malayaman, MD

Abstract

Objectives: Carbon monoxide (CO) derived from cigarette smoke or released from carbon monoxide releasing-molecule 2 (CORM-2), diminishes fibrinolysis. The primary purpose of this study was to determine if CO diminished fibrinolysis by means of enhancing α2-antiplasmin via an alleged heme group. Methods: Plasma, isolated α2-antiplasmin and isolated plasmin were exposed to CO released from CORM-2 (tricarbonyldichlororuthenium (II) dimer) and nitric oxide (NO) via a NO donor to induce carboxyheme and metheme states. Exposed, isolated enzymes were placed in either α2-antiplasmin deficient or normal plasma. Effects of CO and NO on tissue-type plasminogen activator initiated fibrinolysis were determined by thrombelastography. Liquid chromatography-mass spectrometry (LC-MS/MS, see Table 1) was used to identify heme released from α2-antiplasmin and plasmin. Results: CO significantly enhanced α2-antiplasmin activity but decreased plasmin activity. NO decreased both α2-antiplasmin and plasmin activity. While ii insufficient LC-MS/MS data was obtained with α2-antiplasmin (secondary to glycosylation), a putative plasmin-associated heme was identified. Conclusion: CO causes hypofibrinolysis by enhancing α2-antiplasmin activity and decreasing plasmin activity. Based on responses to NO and LCMS/ MS data, it is highly likely that both enzymes are modulated by attached heme groups. Attempts to develop methods to detect CO-mediated hypercoagulability are ongoing, with the goal of identifying populations at risk of thrombotic morbidity secondary to cigarette smoking.

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