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.


METHODS
Myometric biopsies were kept for 10 min or 4 h in a buffer solution at +4 degrees C before preparation into 'early' and 'late' strips, respectively. The strips were perifused at +37 degrees C for different periods of time. Adenylates, energy charge (EC), adenosine and NAD+ were determined in individual strips.


RESULTS
Mean EC and ATP values were low, the 'late' strips displaying 5% and 20% lower values than the 'early' strips, respectively. During perifusion the EC increased slightly, ADP decreased significantly and the strips began to contract. A correlation fitting a multiplicative function was evident between EC and NAD+ (r = 0.89, P < 0.001).


CONCLUSIONS
Human myometrium, 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.
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000328:Adult; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D009215:Myometrium / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D011247:Pregnancy; D014590:Uterine Contraction / Q000502:physiology*
D009243:NAD; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate