title: Characterization of cyclic adenine dinucleotide phosphate ribose levels in human spermatozoa.
abstract: OBJECTIVE
  To determine the presence of the Ca2+-releasing pyridine nucleotide derivative, cyclic adenine dinucleotide phosphate ribose (cADPR), in human spermatozoa and to investigate its role in progesterone-induced Ca2+ oscillations in spermatozoa.
  
  
  METHODS
  Biochemical investigation on human spermatozoa from healthy volunteers.
  
  
  METHODS
  Healthy volunteers in an academic research environment.
  
  
  METHODS
  Ten volunteers.
  
  
  METHODS
  None.
  
  
  METHODS
  The cADPR levels.
  
  
  RESULTS
  Human spermatozoa contain micromolar concentrations of cADPR that do not change significantly during sperm capacitation. An active synthetic machinery for cADPR is present in human spermatozoa, whereas degradation activity is minimal. Although progesterone-induced Ca2+ oscillations are dependent on the ryanodine receptor, they are unaffected by cADPR antagonists.
  
  
  CONCLUSIONS
  It appears that cADPR does not to play a role in Ca2+ oscillations in spermatozoa, but the presence of high concentrations of cADPR suggests that, instead, it may be introduced into the egg at fertilization and play a role in the Ca2+ transient immediately following sperm-egg fusion.
authors.affiliation: DiSCAFF, Universita' del Piemonte Orientale, Novara, Italy.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Billington
authors.forename: Claire
authors.initials: C
authors.lastname: Harper
authors.forename: Elisa A
authors.initials: EA
authors.lastname: Bellomo
authors.forename: Steve
authors.initials: S
authors.lastname: Publicover
authors.forename: Christopher L R
authors.initials: CL
authors.lastname: Barratt
authors.forename: Armando A
authors.initials: AA
authors.lastname: Genazzani
mesh_terms: D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D002478:Cells, Cultured; D036563:Cyclic ADP-Ribose / Q000378:metabolism*; D006801:Humans; D008297:Male; D013075:Sperm Capacitation / Q000502:physiology*; D013094:Spermatozoa / Q000378:metabolism*
chemical_list: D036563:Cyclic ADP-Ribose; D002118:Calcium