Varnell R J, Freeman J Y, Maitchouk D, Beuerman R W, Gebhardt B M
LSU Eye Center, Louisiana State University Medical Center, School of Medicine, New Orleans 70112, USA.
Curr Eye Res. 1997 Sep;16(9):960-3. doi: 10.1076/ceyr.16.9.960.5040.
To determine whether substance P is present in human tears.
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.
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).
These findings demonstrate that substance P is a component of tears obtained from normal eyes of men and women ranging in age from 26 to 60 years, from eyes fitted with contact lenses, from eyes with dry eye syndrome, and from eyes 1 and 2 days after excimer laser refractive surgery. Whether the concentration of substance P in tears varies with sex, age, or eye condition, the source of substance P in tears, and its role in tears remains to be discovered.
确定P物质是否存在于人类眼泪中。
从12名受试者的单眼中收集泪液样本（1 - 2微升）。其中2只眼睛患有干眼综合征，2只佩戴隐形眼镜且患有干眼综合征，8只眼睛正常。8只正常眼睛中有5只计划接受准分子激光屈光手术，在手术前后从这些眼睛中收集眼泪。通过激光解吸质谱法分析泪液样本。对来自同一个体的混合样本进行酶联免疫吸附测定。
18个泪液样本的激光解吸质谱图显示出明确的峰，质荷比（m/z）范围为1343.7至1355.9和/或1356.9至1364.7，对于从浓度范围为10(-4) M至10(-12) M的P物质配制的标准品的14个质谱图，质子化P物质的平均m/z为1349.8 +/- 1.13，氧化P物质的平均m/z为1361.2 +/- 0.54。作为确认，对一只眼睛的混合眼泪进行了两次酶联免疫吸附测定，两次重复测定均检测到浓度为125 pg/ml（9.26 x 10(-11) M）的P物质。
这些发现表明，P物质是年龄在26至60岁的男性和女性正常眼睛、佩戴隐形眼镜的眼睛、患有干眼综合征的眼睛以及准分子激光屈光手术后1至2天的眼睛所产生眼泪的组成成分。眼泪中P物质的浓度是否随性别、年龄或眼部状况而变化，眼泪中P物质的来源及其在眼泪中的作用仍有待发现。
