title: Effects of delta-9-tetrahydrocannabinol, the primary psychoactive cannabinoid in marijuana, on human sperm function in vitro.
abstract: OBJECTIVE
  To investigate effects of delta-9-tetrahydrocannabinol (THC) on human sperm function in vitro.
  
  
  METHODS
  Laboratory analysis of sperm motility after exposure to THC using computer-assisted semen analysis and acrosome reaction by fluoroscein isothiocyanate-labeled peanut agglutinin staining.
  
  
  METHODS
  An assisted reproductive technology unit.
  
  
  METHODS
  Seventy-eight male patients.
  
  
  METHODS
  Sperm were divided into 90% (the best fertilizing potential used in assisted conception) and 45% (the poorer subpopulation) fractions by density centrifugation and incubated with THC at concentrations equivalent to therapeutic (0.032 microM) and recreational (0.32 and 4.8 microM) plasma levels at 37 degrees C for 3 h.
  
  
  METHODS
  Sperm motility and spontaneous and induced acrosome reactions.
  
  
  RESULTS
  Percentage progressive motility was decreased dose dependently in the 90% fraction (by 2%-21%; P<.05; P<.001). The 45% fraction showed a greater decrease in percentage progressive motility (by 28% at 0.032 microM; 56% at 4.8 microM; P=.004 and P=.01 res). Straight line velocity and the average path velocity also were reduced (by 10%, in the 90% LAYER) in both fractions. Spontaneous acrosome reactions were reduced in the 90% (17% at 0.032 microM, 35% at 4.8 microM P=.004 and P<.001 resp) and more markedly in the 45% fractions (17%-35%; P<.001). When the acrosome reaction was artificially induced (90% fraction) by A23187, THC (4.8 microM) resulted in a 57% inhibition (P<.001).
  
  
  CONCLUSIONS
  The use of THC as a recreational drug may adversely affect male fertility.
authors.affiliation: Obstetrics & Gynaecology, School of Medicine, Queen's University, Belfast, United Kingdom.
authors.forename: Lynne B
authors.initials: LB
authors.lastname: Whan
authors.forename: Mhairi C L
authors.initials: MC
authors.lastname: West
authors.forename: Neil
authors.initials: N
authors.lastname: McClure
authors.forename: Sheena E M
authors.initials: SE
authors.lastname: Lewis
mesh_terms: D020101:Acrosome Reaction / Q000187:drug effects*; D000328:Adult; D000001:Calcimycin / Q000494:pharmacology; D002188:Cannabis / Q000737:chemistry*; D013759:Dronabinol / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology*
chemical_list: D007476:Ionophores; D000001:Calcimycin; D013759:Dronabinol