Figure 1.

Agonist-mediated contraction/relaxation of pregnant myometrium. Strips of near-term pregnant non-labouring myometrium approximately 0.5×1×4 mm were dissected from samples taken from consenting women at the time of caesarean section within 90 min of donation. Tissues were hung in organ baths and tension recorded as described in Methods. Addition of agonists was accomplished by addition of 20 μl of concentrated stock to a 20 ml organ bath. Addition of the GC inhibitor ODQ (1 μM) was made 15 min prior to re-challenge with OT while IBTx (100 nM) was given a 1-min pretreatment. Breaks in the tracing occur where rest and washout periods are subtracted from the record. In the presence of ODQ, relaxations to Cys-NO could be seen during the initial contraction as illustrated or following up to 10 min in the presence of OT (not shown). Recording is representative of five experiments of four-tissue strips each and is made up from three periods of recording from a single continuous record of a single tissue strip.