title: Salivary Testosterone during the Minipuberty of Infancy .
abstract: BACKGROUND
  The hypothalamic-pituitary-gonadal axis is transiently activated during the postnatal months in boys, a phenomenon termed "minipuberty" of infancy, when serum testosterone (T) increases to pubertal levels. Despite high circulating T there are no signs of virilization. We hypothesize that free T as measured in saliva is low, which would explain the absence of virilization.
  
  
  METHODS
  We measured serum total T and free T in saliva using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in 30 infant boys, aged 1-6 months, and in 12 adolescents, aged 11-17 years.
  
  
  RESULTS
  Total serum T in all infants was, as expected, high (172 ± 78 ng/dL) while salivary T was low (7.7 ± 4 pg/mL or 0.45 ± 0.20%). In contrast, salivary T in the adolescents was much higher (41 ± 18 pg/mL or 1.3 ± 0.36%) in relation to their total serum T (323 ± 117 ng/dL). We provide for the first time reference data for salivary T in infants.
  
  
  CONCLUSIONS
  Measurement of salivary T by LC-MS/MS is a promising noninvasive technique to reflect free T in infants. The low free T explains the absence of virilization. The minipuberty of infancy is more likely of intragonadal than peripheral significance. .
authors.forename: Maria
authors.initials: M
authors.lastname: Contreras
authors.forename: Manish
authors.initials: M
authors.lastname: Raisingani
authors.forename: Donald Walt
authors.initials: DW
authors.lastname: Chandler
authors.forename: William D
authors.initials: WD
authors.lastname: Curtin
authors.forename: Julia
authors.initials: J
authors.lastname: Barillas
authors.forename: Preneet Cheema
authors.initials: PC
authors.lastname: Brar
authors.forename: Kris
authors.initials: K
authors.lastname: Prasad
authors.forename: Bina
authors.initials: B
authors.lastname: Shah
authors.forename: Raphael
authors.initials: R
authors.lastname: David
mesh_terms: D000293:Adolescent; D002648:Child; D006058:Gonadal Disorders / Q000175:diagnosis / Q000378:metabolism*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012463:Saliva / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism*
chemical_list: D013739:Testosterone