Adrenergic influences on rabbit oviduct: effect of muscle size and ovarian hormones.
This study attempts to distinguish between a direct action of ovarian steroids on adrenergic neurons in the oviduct and an indirect effect mediated by changes in muscle size. Mature rabbits were treated as follows: group 1, ovariectomized and a polyethylene catheter (1 mm OD) inserted into isthmus of one oviduct (CT) with contralateral oviduct as control (C); group 2, normal, estrous animals with one intubated isthmus (ET) and contralateral control (E). Fourteen days postoperatively, oviducts were removed and muscle-wall thickness, norepinephrine (NE) content, and response to nerve stimulation were measured. Although castration atrophy was prevented in CT, NE content of CT was significantly less than C, 0.032 +/- 0.07 versus 1.09 +/- 0.10 nmol. NE content of ET was also significantly less than E (1.32 +/- 0.03 versus 1.81 +/- 2.0) despite a greater wall thickness of ET. It was concluded that: a) withdrawal of ovarian hormones reduces NE contents by a direct action on nerves; b) moderate stretch, per se, increases muscle size and reduces NE content; c) nerve stimulation induces muscle contraction despite large reduction in transmitter content.
D000320:Adrenergic Fibers / Q000502:physiology; D000818:Animals; D002369:Castration; D004971:Estrus; D005187:Fallopian Tubes / Q000033:anatomy & histology / Q000294:innervation / Q000502:physiology*; D005260:Female; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000294:innervation / Q000502:physiology; D009638:Norepinephrine / Q000032:analysis / Q000494:pharmacology; D009929:Organ Size; D011247:Pregnancy; D011817:Rabbits; D013564:Sympathetic Nervous System / Q000502:physiology*
D009638:Norepinephrine