Corpus luteum-uterine relationships in the control of uterine contraction in the lizard Anolis carolinensis

The lizard Anolis carolinensis exhibits unilateral uterine contraction and oviposition. The present study investigated the control of unilateral uterine contraction by exposing uteri to arginine vasotocin (AVT) in vitro. In cycling Anolis females, the uterus on the same side as an ovary with a large corpus luteum failed to contract in vitro in response to AVT. In contrast, the contralateral uterus (on the side where a corpus luteum was degenerating or absent) exhibited rhythmic contractions when exposed to AVT. Unilateral deluteinization removed the unilateral inhibition of uterine contraction. The inhibitory substance(s) produced by the corpus luteum could be delivered to the ipsilateral uterus via small uteroovarian blood vessels.