Water permeability of aquaporin-1(AQP1)expressed in Xenopus oocytes. When transferred to hypo-osmolar buffer for 2 min, control water-injected oocytes exhibit negligible swelling(left). Under the same conditions, oocytes previously injected with AQPI CRNA rapidly swell and explode ( right).Water permeability of aquaporin-1 (AQP1) expressed in Xenopus oocytes. When transferred to hypo-osmolar buffer for 2 min, control water-injected oocytes exhibit negligible swelling (left). Under the same conditions, oocytes previously injected with AQP1 cRNA rapidly swell and explode (right)