ad info




CNN.com
 MAIN PAGE
 WORLD
 U.S.
 LOCAL
 POLITICS
 WEATHER
 BUSINESS
 SPORTS
 TECHNOLOGY
 SPACE
* HEALTH
 AIDS
 Aging
 Alternative
 Cancer
 Children
 Diet & Fitness
 Men
 Women
 ENTERTAINMENT
 BOOKS
 TRAVEL
 FOOD
 ARTS & STYLE
 NATURE
 IN-DEPTH
 ANALYSIS
 myCNN

 Headline News brief
 news quiz
 daily almanac

  MULTIMEDIA:
 video
 video archive
 audio
 multimedia showcase
 more services

  E-MAIL:
Subscribe to one of our news e-mail lists.
Enter your address:
Or:
Get a free e-mail account

 DISCUSSION:
 message boards
 chat
 feedback

  CNN WEB SITES:
CNN Websites
 AsiaNow
 En Español
 Em Português
 Svenska
 Norge
 Danmark
 Italian

 FASTER ACCESS:
 europe
 japan

 TIME INC. SITES:
 CNN NETWORKS:
Networks image
 more networks
 transcripts

 SITE INFO:
 help
 contents
 search
 ad info
 jobs

 WEB SERVICES:

  health > story pageAIDSAgingAlternative MedicineCancerChildrenDiet & FitnessMenWomen

Links found between marijuana and vision

marajuana

December 7, 1999
Web posted at: 2:47 p.m. EST (1947 GMT)


In this story:

'Nature likes to tinker'

New piece to puzzle of eye function

RELATED STORIES, SITES icon



WASHINGTON (Reuters) -- The active ingredient in marijuana and hashish may affect vision by plugging into tailor-made receptors in the eye, researchers said Monday.

They said they found the receptors -- which are chemical doorways into cells -- in animals ranging from chicks to salamanders to monkeys.

  MESSAGE BOARD
Medical marijuana
 

This suggests that chemicals similar to the cannabinoids in hashish and marijuana, known to occur naturally in the human body, are ancient and highly important in eye function, the researchers said.

"The fact that this system is so highly conserved in species separated by hundreds of millions of years of evolution suggests that it's important," Alex Straiker of the University of California, San Diego, who led the research, said in a statement.

'Nature likes to tinker'

"Nature likes to tinker, so any time you see something this consistent, it raises eyebrows."

Working with colleagues at the Neurosciences Institute in San Diego and the University of Washington in Seattle, Straiker found cannabinoid receptors known as CB1 receptors in the retinal cells of rhesus monkeys, chicks, salamanders, goldfish, mice and rats.

They also occurred in both the rods and cones, which are the eye structures that respond to light, the researchers wrote in a report in the Proceedings of the National Academy of Sciences.

New piece to puzzle of eye function

"We understand very little about how the retina works. By demonstrating that this receptor system is present, we add another piece to the puzzle, opening one more window into how the eye works," Straiker said.

"It also suggests that marijuana affects vision, because it plugs into an existing signaling system that is abundant in the retina."

Cannabinoids naturally occur in vertebrates. For instance, pain triggers the release of one class of cannabinoids known as anandamides. Anandamides are neurotransmitters, or message-carrying chemicals.

The chemical THC found in marijuana also is a cannabinoid.

Cannabis has been used for centuries to help relieve pain, and some research suggests it can affect vision and also may be able to help relieve symptoms of the eye disease glaucoma.

Researchers think THC must plug into the body's natural system for using anandamide and other neurotransmitters.



RELATED STORIES:
Medical marijuana grower slapped with stiff sentence
Federal report reignites medical marijuana debate
Study casts doubt on marijuana's effectiveness as glaucoma treatment
Medical marijuana popular at polls
Experts urge new study of medical uses of marijuana
Weed Wars

RELATED SITES:
U.S. Department of Justice
Californians for Compassionate Use
Medical marijuana - The jury's still out
NORML - Working to Reform Marijuana Laws
Note: Pages will open in a new browser window
External sites are not endorsed by CNN Interactive.

LATEST HEALTH STORIES:
 LATEST HEADLINES:
SEARCH CNN.com
Enter keyword(s)   go    help

Back to the top   © 2001 Cable News Network. All Rights Reserved.
Terms under which this service is provided to you.
Read our privacy guidelines.