AJP - Cell Physiology, Vol 234, Issue 3 96-101, Copyright © 1978 by American Physiological Society
Adrenergic influences on rabbit oviduct: effect of muscle size and ovarian hormones
H. Meiri, U. Meiri, D. R. Kennedy and J. M. Marshall
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.
