Pubdate: Wed, 13 Dec 2000 Source: Atlanta Journal-Constitution (GA) Copyright: 2000 Cox Interactive Media. Contact: Journal: Constitution: http://www.accessatlanta.com/ajc/ Forum: http://www.accessatlanta.com/community/forums/ Author: Ulysses Torassa - San Francisco Chronicle STUDY: MARIJUANA USE MAY HURT CHANCES OF CONCEPTION In a finding that could send shivers down the spines of pot-smoking couples hoping to conceive, new research is raising the possibility that marijuana could interfere with reproduction. New studies show that a cannabis-like compound inhibits the ability of human sperm to fertilize an egg. Also, high concentrations of THC --- the psychoactive ingredient in marijuana --- appear to cause structural changes in sperm as they become ready and able to reach and fuse with a woman's egg. While pot smoking may not yet qualify as a contraceptive, the findings presented Tuesday at the American Society for Cell Biology meeting in San Francisco are some of the first indications that marijuana use could reduce fertility in both men and women. Previous research has shown a link between heavy pot smoking and low sperm counts. The latest study focuses on a substance called anandamide that is produced by the body and which acts very much like THC on a cellular level. It is one of a class of substances called cannabinoids that bind to receptors on cells that also respond to THC. Cannabinoids are found throughout the body and their affect on various systems is only now being studied. In a series of experiments, researchers at the University of Buffalo-SUNY found that a synthetic form of anandamide reduced by half the number of sperm that were able to attach to a human egg. Furthermore, high concentrations of anandamide slowed down sperm's swimming ability, while low levels kicked it into overdrive. The researchers also bathed human sperm in solutions containing either THC or anandamide and found that both substances significantly altered the normal structural changes sperm go through as they prepare to approach and bind with an egg. ''For people who are very heavy marijuana users, there may be reproductive consequences associated with that,'' said Herbert Schuel, a professor of anatomy and cell biology at the University of Buffalo and lead author of the study. More generally, Schuel said, it is possible that glitches in the normal anandamide system could be linked to some cases of unexplained infertility. - --- MAP posted-by: Keith Brilhart