Navigation Links
Tears reveal some of their deepest secrets to researchers

It's no secret why we shed tears. But exactly what our tears are made of has remained a mystery to scientists.

A new study sheds some light on the complex design of tears. What we think of as tears, scientists call tear film, which is made up of three distinct, microscopic layers. The middle, watery layer ?what we normally think of as tears when we cry ?is sandwiched between a layer of mucus and an outer layer of fatty, oily substances collectively called meibum.

It's in this outer layer that researchers describe, for the first time, a new class of lipids ?a type of fat ?that make up part of the film. They also identified one of these lipids, oleamide, which had not been known to be a part of tears before.

With each blink, meibum spreads over the surface of the eye. It keeps the watery middle layer in place, ensuring that our eyes stay moist.

Finding these lipids may help scientists better understand the causes of eye-related disorders such as dry eye disease, which affects anywhere from 12 to 14 million Americans, said Kelly Nichols, the study's lead author and an assistant professor of optometry at Ohio State University.

"The lack of certain compounds in the tear film may result in a number of different eye-related disorders, including dry eye," she said. "The amount of oleamide and related lipids in tear film may be related to these disorders."

Dry eye is really a collection of irritating symptoms that includes microscopic damage to the front of the eye. The eyes may ache, burn, feel extremely dry or excessively tear.

The researchers report their findings in the current issue of the journal Investigative Ophthalmology and Visual Science.

They collected oily meibum secretions from the meibomian glands of healthy volunteers. The meibomian glands are tiny, grape-like clusters of cells that line the rim of our upper and lower eyelids ?the outlets to these glands are roughly adjacent to the e yelashes. Researchers gently pressed the volunteers' lower eyelids and collected droplets of meibum in tiny glass tubes.

The researchers examined the meibum samples in the laboratory. They used a technique called electrospray mass spectrometry to differentiate between the different lipid components. This technique adds an electric charge to microscopic droplets of the oily substance, which allows the instrument to detect different components based on electrical charges and mass.

Nichols points out that researchers have used other techniques, such as chromatography, to characterize types of lipids in the tear film, but advances in mass spectrometry technology are improving research efforts.

"Other scientists used different techniques to try to determine the composition of meibum, but mass spectrometry is sensitive enough to detect individual lipid molecules, like oleamide," Nichols said.

Oleamide was first identified as a lipid in the brain, where one of its roles is to induce sleep. It also has other key functions throughout the central nervous system. But the current study is the first to find and describe oleamide and related lipids in tear film.

"The finding could give us more insight into the role of lipid activity in humans and may also indicate a new function for oleamide and related lipids in cellular signaling in the eye and in the maintenance of tear film," said Nichols, adding that researchers don't fully understand the function of oleamide, or the other lipids in the meibum.

"Oleamide appears to be a predominate lipid in tear film," she said. "It's there for a reason, but we're not sure yet what that reason is."

Nichols and her team are currently studying the role of oleamide in cellular signaling and communication in the eye, along with the role that the lipid may play in dry eye.

"Dry eye is really a disorder of symptoms that irritate the eyes," Nichols said. "Not everyone w ith dry eye responds to the same treatment. If we could find individuals with varying oleamide levels, then we may be able discern one cause of dry eye, and specifically treat that.

"Even though two people with dry eye may have the same symptoms, there may be very different causes underlying those symptoms."
'"/>

Source:Ohio State University


Related biology news :

1. Elusive HIV shape change revealed; Key clue to how virus infects cells
2. Timing is everything: First step in protein building revealed
3. Researchers reveal the infectious impact of salmon farms on wild salmon
4. A bacterial genome reveals new targets to combat infectious disease
5. Scientists reveal molecular secrets of the malaria parasite
6. Studies reveal methods viruses use to sidestep immune system
7. First real-time view of developing neurons reveals surprises, say Stanford researchers
8. Examination of internal wiring of yeast, worm, and fly reveals conserved circuits
9. Family trees of ancient bacteria reveal evolutionary moves
10. NYU study reveals how brains immune system fights viral encephalitis
11. Iron exporter revealed that may explain common human disorder

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:5/3/2016)... 2016  Neurotechnology, a provider of high-precision biometric ... Biometric Identification System (ABIS) , a complete system ... ABIS can process multiple complex biometric transactions with ... fingerprint, face or iris biometrics. It leverages the ... MegaMatcher Accelerator , which have been used ...
(Date:4/19/2016)... 2016 The new GEZE SecuLogic ... web-based "all-in-one" system solution for all door components. It ... the door interface with integration authorization management system, and ... The minimal dimensions of the access control and the ... installations offer considerable freedom of design with regard to ...
(Date:3/31/2016)... 31, 2016   ... the "Company") LegacyXChange is excited to release ... soon to be launched online site for trading 100% ... ) will also provide potential shareholders a sense of ... to an industry that is notorious for fraud. The ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... June 23, 2016   Boston Biomedical , ... compounds designed to target cancer stemness pathways, announced ... granted Orphan Drug Designation from the U.S. Food ... gastric cancer, including gastroesophageal junction (GEJ) cancer. Napabucasin ... to inhibit cancer stemness pathways by targeting STAT3, ...
(Date:6/23/2016)... HOUSTON , June 23, 2016 ... agreement with the Cy-Fair Sports Association to serve ... of the agreement, Houston Methodist Willowbrook will provide ... education and connectivity with association coaches, volunteers, athletes ... partner with the Cy-Fair Sports Association and to ...
(Date:6/23/2016)... -- The Biodesign Challenge (BDC), a university competition that asks ... systems and biotechnology, announced its winning teams at the ... York City . The teams, chosen ... MoMA,s Celeste Bartos Theater during the daylong summit. Keynote ... of architecture and design, and Suzanne Lee , ...
(Date:6/23/2016)... ... June 23, 2016 , ... STACS DNA Inc., the sample tracking ... Arkansas State Crime Laboratory, has joined STACS DNA as a Field Application Specialist. ... Jocelyn Tremblay, President and COO of STACS DNA. “In further expanding our capacity as ...
Breaking Biology Technology: