Featured Research

from universities, journals, and other organizations

Sigma Receptors Play Role In Cocaine-induced Suppression Of Immune System

Date:
May 6, 2003
Source:
NIH/National Institute On Drug Abuse
Summary:
Cocaine use is known to have negative effects on the immune system but how the drug exerts this effect is poorly understood. Now a research team, led by Dr. Steven Dubinett from the University of California Los Angeles Lung Cancer Research Program, has demonstrated that some of cocaine's effects on the immune system may be mediated by sigma receptors.

Cocaine use is known to have negative effects on the immune system but how the drug exerts this effect is poorly understood. Now a research team, led by Dr. Steven Dubinett from the University of California Los Angeles Lung Cancer Research Program, has demonstrated that some of cocaine's effects on the immune system may be mediated by sigma receptors. These receptors are unique proteins found in the brain and other areas of the body and have been shown to play a role in some of the toxic and behavioral effects of the drug.

The researchers administered cocaine or saline to male mice five times per week. Another group of mice were given the sigma receptor antagonist BD1047--a substance that blocks the sigma receptors and does not stimulate them--in addition to cocaine or saline. After 2 weeks, tumor cells were implanted in the mice. Tumor growth and interleukin (IL)-10 concentrations were measured. IL-10 is a chemical messenger that suppresses the production of several substances that inhibit tumor growth. Tumors in cocaine-exposed mice were significantly larger and contained higher levels of IL-10 than those in saline-treated mice. However, tumor growth was less enhanced in mice who received both cocaine and treatment with the sigma receptor antagonist BD1047. In addition, administration of anti-IL-10 antibody reversed the tumor growth-promoting effects of sigma ligand agonists--substances that bind to and stimulate the receptors--such as cocaine.

In a separate study, the researchers administered cocaine or saline and the sigma receptor antagonist BD1047 to male mice. Two weeks later, the mice were administered staphylococcal entertoxin, which promotes IL-10 production by immune cells. The researchers found that the level of IL-10 in the blood of cocaine-exposed mice was significantly higher than those receiving saline but IL-10 production was inhibited in mice who received the sigma receptor antagonists.

WHAT IT MEANS: These finding suggest that cocaine and other drugs that stimulate sigma receptors may promote tumor growth by increasing the production of immunosuppressive chemical messengers. However, the researchers say that further research is needed to determine whether cocaine causes cancer.

This study, cofunded by the National Institute on Drug Abuse, was published in the April 1 issue of The Journal of Immunology.


Story Source:

The above story is based on materials provided by NIH/National Institute On Drug Abuse. Note: Materials may be edited for content and length.


Cite This Page:

NIH/National Institute On Drug Abuse. "Sigma Receptors Play Role In Cocaine-induced Suppression Of Immune System." ScienceDaily. ScienceDaily, 6 May 2003. <www.sciencedaily.com/releases/2003/05/030506073758.htm>.
NIH/National Institute On Drug Abuse. (2003, May 6). Sigma Receptors Play Role In Cocaine-induced Suppression Of Immune System. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2003/05/030506073758.htm
NIH/National Institute On Drug Abuse. "Sigma Receptors Play Role In Cocaine-induced Suppression Of Immune System." ScienceDaily. www.sciencedaily.com/releases/2003/05/030506073758.htm (accessed July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins