Effect of Stimulus on the Chemical Composition of Human Tears

doi:10.1016/0002-9394(81)90651-6

American Journal of Ophthalmology

Volume 92, Issue 4, October 1981, Pages 559-567

https://doi.org/10.1016/0002-9394(81)90651-6 Get rights and content

We examined the effect of the nature of the stimulus on the chemical composition of human tears. The protein concentration of emotional tears from women exceeded that of irritant-induced tears by 24% (P<.01). Polyacrylamide disk gel electrophoresis disclosed no significant difference between the distribution of positively or negatively charged proteins of irritant-induced and emotional tears. Manganese concentrations in tears (30 ng/ml) exceeded serum concentrations from the same subjects by 30-fold. These manganese concentrations in tears were considerably less than previously reported values. We found no differences for the concentrations of protein or manganese in human tears between the sexes.

References (34)

F.J. Holly et al.
Surface activity determination of aqueous tear components in dry eye patients and normals
Exp. Eye Res.
(1977)
J. Versieck et al.
Normal levels of trace elements in human blood plasma or serum
Anal. Chim. Acta
(1980)
J. Allerhand et al.
Electrophoresis and immunoelectrophoresis of neonatal tears
J. Pediatr.
(1963)
W.K. McEwen et al.
Filter-paper electrophoresis of tears. III. Human tears and their high molecular weight components
Am. J. Ophthalmol.
(1958)
N.J. van Haeringen et al.
The origin of some enzymes in tear fluid, determined by comparative investigation with two collection methods
Exp. Eye Res.
(1976)
E. Goldberg
Amino acid comsition and properties of crystalline lactate dehydrogenase X from mouse testes
J. Biol. Chem.
(1972)
M.M. Bradford
A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding
Anal. Biochem.
(1976)
A.F. Fourcroy et al.
The chemical examination of tears and of the nasal secretion
Ann. Chimie
(1791)
P.L. Altman
Physical properties and chemical composition of tears. Man
T. Sorensen et al.
Methodological aspects of tear flow determination by means of a radioactive tracer
Acta Ophthalmol.
(1977)

M.S. Norn

Outflow of tears and its influence on tear secretion and break up time (B.U.T.)

Acta Ophthalmol.

(1977)

L.G. Carney et al.

Human tear pH. Diurnal variations

Arch. Ophthalmol.

(1976)

A.F. Winder et al.

Tear calcium levels and contact lens wear

Br. J. Ophthalmol.

(1977)

G. Horowitz et al.

Calcium in tears, lacrimal gland fluid, and fluid from the other orbital glands

Invest. Ophthalmol.

(1976)

N.J. van Haerington et al.

Collection method dependant concentrations of some metabolites in human tear fluid, with special reference to glucose in hyperglycaemic conditions

Albrecht von Graefes Arch. Klin. Exp. Ophthalmol.

(1977)

R.M. Hill et al.

Human tear cholesterol levels

Arch. Ophthalmol.

(1976)

T.V. Zubareva et al.

Catacholamine content of the lacrimal fluid of healthy people and glaucoma patients

Ophthalmologica

(1977)

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This is not surprising as human tears have a different physiological function, as discussed above. Moreover, they are produced by the lacrimal glands located above the eyes and the amount of water responds to the degree of irritation [39]. In addition to water, crying tears contain various electrolytes (Na+, K+, Cl−, HCO3−), Ca/Mg, fatty oils, antibodies, lysozymes (antibacterial enzymes) and many different proteins [40].
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Notably, daily wear of contact lenses is considered ‘safe’ in people with diabetes as they do not cause significant differences in terms of bulbar redness, corneal staining, corneal thickness, and corneal sensitivity and do not compromise corneal integrity. The second reason is that the glucose monitoring can be carried out directly through tear secretion and blinking, while sample collection with the aid of external stimuli could potentially alter the tear fluid composition [15]. The third reason is contact lenses are easy to wear, use, and remove.
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This work was supported by grant No. 8241 from the St. Paul-Ramsey Hospital Medical Education and Research Foundation (Dr. Frey).

Reprint requests to Wilham H. Frey II, Ph.D., Department of Psychiatry, St. Paul-Ramsey Medical Center, 640 Jackson St., St. Paul, MN 55101.

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Effect of Stimulus on the Chemical Composition of Human Tears

Exp. Eye Res.

Anal. Chim. Acta

J. Pediatr.

Am. J. Ophthalmol.

Exp. Eye Res.

J. Biol. Chem.

Anal. Biochem.

The chemical examination of tears and of the nasal secretion

Ann. Chimie

Physical properties and chemical composition of tears. Man

Methodological aspects of tear flow determination by means of a radioactive tracer

Acta Ophthalmol.

Outflow of tears and its influence on tear secretion and break up time (B.U.T.)

Acta Ophthalmol.

Human tear pH. Diurnal variations

Arch. Ophthalmol.

Tear calcium levels and contact lens wear

Br. J. Ophthalmol.

Calcium in tears, lacrimal gland fluid, and fluid from the other orbital glands

Invest. Ophthalmol.

Collection method dependant concentrations of some metabolites in human tear fluid, with special reference to glucose in hyperglycaemic conditions

Albrecht von Graefes Arch. Klin. Exp. Ophthalmol.

Human tear cholesterol levels

Arch. Ophthalmol.

Catacholamine content of the lacrimal fluid of healthy people and glaucoma patients

Ophthalmologica