Contractile Activity in the Chick Uterus

Uterine contractile activity has never been investigated in chicks. The aim of this study was to investigate spontaneous contraction and response to an agonist of chick uterus. Chicks were scarified by cervical dislocation. The uteri were isolated and contraction measured in vitro. Spontaneous contraction can be observed in 4 days chick uterus. External calcium is necessary for the spontaneous activity and it enters the uterus via L-type voltage-gated calcium channels. The chick uterus was responsive to an agonist such as Prostaglandin F2α (PGF2α). As with spontaneous contraction, the contraction stimulated by PGF2α is dependent on external calcium. However, PGF2α can induce a transient contraction when external calcium is omitted suggesting the ability of the uterus to release calcium from internal sources. Taken together, the data suggest that in the chick uterus spontaneous activity is already present by day 4th and that receptor coupling and excitation-contraction signaling pathways are also functional.