although in preterm myometrium ( 32-35 weeks of pregnancy ) beta-adrenergic receptors are positively coupled to adenylate cyclase , we found that isoproterenol , epinephrine , and norepinephrine did not stimulate the enzyme in the inner or outer myometrial layer at term ( 39-40 weeks of pregnancy ) .
C0014563
epinephrine
C0028351
norepinephrine