Cannabinoids inhibit the respiration of human sperm.
OBJECTIVE
To investigate the effects of the psychotropic compounds Delta(9)-tetrahydrocannabinol (Delta(9)-THC) and Delta(8)-tetrahydrocannabinol (Delta(8)-THC) on sperm mitochondrial O(2) consumption (respiration).


METHODS
State University of New York Upstate Medical University, Syracuse, New York.


METHODS
Forty-one men who visited the andrology laboratory for fertility evaluation.


METHODS
None.


METHODS
A phosphorescence analyzer that measures O(2) concentration in sperm suspensions as a function of time was used to measure respiration.


RESULTS
An immediate decline in the rate of respiration was observed when Delta(9)-THC or Delta(8)-THC was added to washed sperm. The inhibition was concentration dependent, and Delta(9)-THC was the more potent of the two compounds. Respiration was much less affected when Delta(9)-THC or Delta(8)-THC was added to neat semen, suggesting the presence of protective factors in seminal plasma. Both compounds inhibited the respiration of isolated mitochondria, illustrating that direct mitochondrial damage is likely the primary mechanism of action.


CONCLUSIONS
The two main active cannabinoids of the marijuana plant, Delta(9)- and Delta(8)-THC, are potent inhibitors of mitochondrial O(2) consumption in human sperm. These findings emphasize the adverse effects of these toxins on male fertility. The cytoprotective capacity of seminal plasma deserves further investigation.
Department of Pediatrics, State University of New York, Upstate Medical University, Syracuse, New York 13210, USA.
Zaki S
ZS
Badawy
Kazim R
KR
Chohan
Donna A
DA
Whyte
Harvey S
HS
Penefsky
Oliver M
OM
Brown
Abdul-Kader
AK
Souid
D002186:Cannabinoids / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D013759:Dronabinol / Q000494:pharmacology; D000431:Ethanol / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008297:Male; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D010100:Oxygen / Q000032:analysis; D010101:Oxygen Consumption / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology*
D002186:Cannabinoids; D000431:Ethanol; D013759:Dronabinol; D010100:Oxygen