title: Correlation between seminal carnitine and functional spermatozoal characteristics in men with semen dysfunction of various origins.
abstract: OBJECTIVE
  L-carnitine is an essential molecule involved in mitochondrial metabolism, controlling the transport of acetyl and acyl groups across the mitochondrial inner membrane. Carnitine and acetylated carnitine (L-acetylcarnitine) are found in high concentrations in the epididymis, where they also act as antioxidants, protecting spermatozoa against damage caused by reactive oxygen species. In this open study we investigated the correlation between seminal carnitine levels and spermatozoal function, and the effect of combined L-carnitine + L-acetylcarnitine therapy, in infertile men.
  
  
  METHODS
  170 infertile men were enrolled in this study. Patients were divided into those with a total sperm motility below the normal WHO range (<50% motility, group 1 [n = 102]) and those with total sperm motility within the normal range (> or =50% motility, group 2 [n = 68]). Patients in group 1 were further divided into two groups: those with primary or secondary azoospermia (1B [n = 36]), and those without (1A [n = 66]). Patients in group 1A received L-carnitine 1 g/day and L-acetylcarnitine 500 mg twice daily for 6 months. Seminal carnitine levels were measured and correlated with sperm count and motility, eosin test, hypo-osmotic swelling test, acridine orange test for sperm nuclear DNA integrity and sperm kinetics evaluated by computer-assisted sperm analysis in all patients.
  
  
  RESULTS
  There was a significant correlation between seminal carnitine concentration and sperm concentration, total sperm count, sperm total motility, rapid forward progression, live sperm count, membrane function, nuclear DNA integrity, capacity for cervical mucus penetration, linearity of spermatic movement, and amplitude of lateral sperm head movement (all p < 0.0001) in the entire study population. In group 1A, there was a significant increase in total motility, live sperm count, membrane integrity and linearity of spermatic movement after 3 and 6 months of L-carnitine/L-acetylcarnitine treatment, and in capacity for cervical mucus penetration after 6 months of treatment, compared with baseline.
  
  
  CONCLUSIONS
  Seminal carnitine concentration may be an appropriate marker of sperm and epididymal function. L-carnitine/L-acetylcarnitine treatment may be an effective therapy to improve mainly functional seminal parameters.
authors.affiliation: Department of Molecular and Clinical Endocrinology and Oncology, University of Naples Federico II, Naples, Italy. miderosa@unina.it
authors.forename: Michele
authors.initials: M
authors.lastname: De Rosa
authors.forename: Bartolomeo
authors.initials: B
authors.lastname: Boggia
authors.forename: Biagio
authors.initials: B
authors.lastname: Amalfi
authors.forename: Stefano
authors.initials: S
authors.lastname: Zarrilli
authors.forename: Angela
authors.initials: A
authors.lastname: Vita
authors.forename: Annamaria
authors.initials: A
authors.lastname: Colao
authors.forename: Gaetano
authors.initials: G
authors.lastname: Lombardi
mesh_terms: D000108:Acetylcarnitine / Q000627:therapeutic use; D000165:Acridine Orange; D000328:Adult; D002331:Carnitine / Q000378:metabolism / Q000627:therapeutic use*; D004801:Eosine Yellowish-(YS); D006801:Humans; D007248:Infertility, Male / Q000188:drug therapy*; D008297:Male; D009845:Oligospermia / Q000188:drug therapy; D012661:Semen / Q000378:metabolism*; D013076:Sperm Count; D013081:Sperm Motility / Q000187:drug effects; D013084:Sperm-Ovum Interactions / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D000108:Acetylcarnitine; D000165:Acridine Orange; D002331:Carnitine; D004801:Eosine Yellowish-(YS)