Not a specific recommendation, but we can give you a number of other sources for anti-Rat AQP4 to explore. Just search http://www.linscottsdirectory.com/search/antibodies for Aquaporin 4, selecting Rat and WB from the pull down filters. Hope this helps.

I would look at Dr. Mark Knepper's work from the NIH.  He is the guru of AQPs and I am sure that his papers have references to antibodies used.

 Thank you both very much for  the advice!