ENERGY ECONOMY OF HUMAN UTERINE MUSCLE STRIPS UNDER DIFFERENT IN-VITRO CONDITIONS AND ITS DEPENDENCE ON TISSUE REDOX POTENTIAL

Objective: To study the energy economy of human myometrium in vitro, S tudy design: Myometric biopsies were kept for 10 min or 4 h in a buffe r solution at +4 degrees C before preparation into 'early' and 'late' strips, respectively. The strips were perifused at +37 degrees C for d ifferent periods of time. Adenylates, energy charge (EC), adenosine an d NAD(+) were determined in individual strips. Results. Mean EC and AT P values were low, the 'late' strips displaying 5% and 20% lower value s than the 'early' strips, respectively. During perifusion the EC incr eased slightly, ADP decreased significantly and the strips began to co ntract. A correlation fitting a multiplicative function was evident be tween EC and NAD(+) (r = 0.89, P < 0.001). Conclusion: Human myometriu m, being operative at an unusually low EC level, maintained its energy economizing and contractile functions in vitro for 4 h, displaying a tight relationship between EC and NAD(+), suggestive of a compromised energy balance.