Abstract | PURPOSE: To determine whether substance P is present in human tears. METHODS: Tear samples (1-2 microliters) were collected from one eye of each of 12 subjects. Two of the eyes had dry eye syndrome, two wore contact lenses and had dry eye syndrome, and eight were normal. Five of the eight normal eyes were scheduled to undergo excimer laser refractive surgery, and tears were collected from these eyes before and after surgery. Tear samples were analyzed by laser desorption mass spectrometry. Pooled samples from one individual were subjected to enzyme-linked immunoabsorbent assay. RESULTS:
Laser desorption mass spectra of the 18 tear samples displayed well defined peaks with mass to charge (m/z) ratios ranging from 1343.7 to 1355.9 and/or 1356.9 to 1364.7, corresponding to an average m/z of 1349.8 +/- 1.13 for protonated substance P and 1361.2 +/- 0.54 for oxidized substance P obtained from 14 mass spectra of standards formulated with substance P concentrations ranging from 10(-4) M to 10(-12) M. As confirmation, an enzyme-linked immunoabsorbent assay performed twice on pooled tears from one eye detected substance P in both replicates at a concentration of 125 pg/ml (9.26 x 10(-11) M). CONCLUSIONS:
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Authors | R J Varnell, J Y Freeman, D Maitchouk, R W Beuerman, B M Gebhardt |
Journal | Current eye research
(Curr Eye Res)
Vol. 16
Issue 9
Pg. 960-3
(Sep 1997)
ISSN: 0271-3683 [Print] England |
PMID | 9288460
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
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Topics |
- Adult
- Enzyme-Linked Immunosorbent Assay
- Female
- Humans
- Male
- Middle Aged
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Substance P
(metabolism)
- Tears
(metabolism)
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