The water-absorption region of ventral skin of several semiterrestrial and aquatic anuran amphibians identified by aquaporins.

Regions of specialization for water absorption across the skin of Bufonid and Ranid anurans were identified by immunohistochemistry and Western blot analysis, using antibodies raised against arginine vasotocin (AVT)-stimulated aquaporins (AQPs) that are specific to absorbing regions of Hyla japonica. In Bufo marinus, labeling for Hyla urinary bladder-type AQP (AQP-h2), which is also localized in the urinary bladder, occurred in the ventral surface of the hindlimb, pelvic, and pectoral regions. AQP-h2 was not detected in any skin regions of Rana catesbeiana, Rana japonica, or Rana nigromaculata.