In vivo creatine kinase reaction kinetics at rest and stress in type II diabetic rat heart

• DOI: 10.14814/phy2.12248
• Publication Date: 2015-01-28T03:58:20Z
• Authors: Adil Bashir; Andrew R. Coggan; Robert J. Gropler
• Keywords: Creatine kinase; Adenosine triphosphate; Creatine

The effects of type II diabetes on cardiac creatine kinase (CK) enzyme activity and/or flux are unknown. We therefore measured steady-state phosphocreatine (PCr) and adenosine triphosphate (ATP) content forward CK reaction kinetic parameters in Zucker Diabetic Fatty (ZDF) rat hearts, a research model. At baseline the PCr to ATP ratio (PCr/ATP) was significantly lower diabetic heart when compared with matched controls (1.71 ± 0.21 vs. 2.26 0.24, P < 0.01). Furthermore, rate constant (kf) higher animals (0.52 0.09 s(-1) 0.35 0.06 s(-1), 0.01) calculated as product concentration ([PCr]) kf similar between two groups (4.32 1.05 μmol/g/s 4.94 1.23 μmol/g/s, = 0.20). Dobutamine administration resulted increases (~38%) (~0.12 s(-1)) both groups. No significant change observed dobutamine. In summary, our data showed reduced PCr/ATP myocardium an indicator energy deficit. is elevated at which might reflect compensatory mechanics support through shuttle maintain supply. When hearts were stimulated increase thus it seems that does not limit supply for range workload studied.