Response of amphibian (Ambystoma tigrinum) oviduct to arginine vasotocin and acetylcholine in vitro: influence of steroid hormone pretreatment in vivo.

Oviducts of the salamander Ambystoma tigrinum contract in vitro in response to stimulation by arginine vasotocin (AVT) and acetylcholine (ACh). Steroid hormone pretreatment significantly affects the responsiveness of the oviductal tissue to AVT and ACh. Oviducts initially pretreated with estradiol, testosterone and saline or a combination of estradiol and testosterone exhibit no response to AVT and only saline or estradiol/testosterone treated oviducts respond to ACh. Secondary pretreatment with progesterone stimulated a significant increase in responsiveness to AVT and ACH in all groups.