Group IIA phospholipase A2 content of basal, nonstimulated and reflex tears.

Purpose: To determine the concentration of group IIA phospholipase A2 (GIIAPLA(2)) in basal, nonstimulated and reflex tears of young normal subjects.

Methods: The GIIAPLA(2) content of tears was measured in left eye of 16 healthy subjects (mean age 24.5 +/- 2.2 years). Five samples were taken from each subject: nonstimulated sample; basal sample in a dark room after topical anesthesia; and reflex tear samples immediately on stimulation by bright light and breathing of the vapor of onions, and 1 and 3 minutes after the onset of tear flow.

Results: The GIIAPLA(2) content of reflex tears was statistically significantly lower than the GIIAPLA(2) content of basal tears, whereas there was no statistically significant difference in the GIIAPLA(2) content between nonstimulated and basal tears.

Conclusions: The current results indicate that the basal and nonstimulated tears are similar in their GIIAPLA(2) content, and that the GIIAPLA( 2) content of tears decreases with stimulation, possibly due to dilution of GIIAPLA(2) content during reflectory hypersecretion of tears.