VIP immunoreactivity in human aqueous humor.
OBJECTIVE
To demonstrate the presence of vasoactive intestinal pep-tide (VIP)-immunoreactive molecule in the human aqueous humor collected from eyes undergoing either cataract or glaucoma surgeries and to identify them asses of molecules responsible for the VIP immunoreactivity.


METHODS
Aqueous humor specimens were collected by parencentesis from nine cataract patients and also from eight patients undergoing glaucoma surgery following the creation of the limbal based conjunctival flap, partial dissection of the scleral flap, and application of mitomycin-C. The aqueous humor specimens were analyzed by radioimmunoassay to determine the level of VIP immunoreactivity. Specimens from 10 other cataract patients were pooled and analyzed for VIP immunoreactivity by Western blot analysis.


RESULTS
Levels of VIP immunoreactivity in aqueous humor of cataract and glaucoma patients were significantly different and were 610 +/- 160 and 260 +/- 64 pg VIP/ml, respectively (p = 0.03), while there was no correlation between the donor age and the level of VIP immunoreactivity. VIP immunoreactivity was detected as a single molecule with a molecular weight of 9000.


CONCLUSIONS
The disease status and the treatments of the eye that led to surgery and procedures applied to the eye immediately before aqueous humor collection, but not the age of the patients, affected the level of VIP immunoreactivity in the aqueous humor. The relationship between the 9000 Da VIP-immunoreactive molecule and the authentic (3326 Da) VIP remains to be studied.
Koh
Shay-Whey
SW
Department of Ophthalmology, University of Maryland, Baltimore, Maryland 21201, USA. skoh@umaryland.edu
Rutzen
Allan
A
Coll
Timothy
T
Hemady
Ramzi
R
Higginbotham
Eve
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001082:Aqueous Humor / Q000378:metabolism*; D015153:Blotting, Western; D002387:Cataract Extraction; D006801:Humans; D008875:Middle Aged; D008970:Molecular Weight; D011863:Radioimmunoassay; D014130:Trabeculectomy; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
D014660:Vasoactive Intestinal Peptide