title: Transient increase in postnatal testicular activity is not revealed by longitudinal measurements of salivary testosterone.
abstract: Testicular steroidogenic activity in 22 boys was monitored longitudinally over the first 6 months of life using salivary T measurements. Samples were collected biweekly. The highest T levels, 130 +/- 12 pmol/liter (mean +/- SE, n = 22), were observed on days 2-10. The values then gradually declined to a mean of about 30 pmol/liter after month 4. No secondary peak in salivary T appeared, in contrast to the 1-3 month peak in serum T previously reported. The overall levels of T, reflected by the areas under the T concentration curves over the whole period, varied by a factor of three among the subjects studied. It is concluded that postnatal testicular activity may have its most marked physiologic effects immediately after birth rather than at the time of the 1-3-month peak of serum T. Furthermore, the overall exposure to androgen is individually greatly variable.
mesh_terms: D000367:Age Factors; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012463:Saliva / Q000032:analysis*; D013737:Testis / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism*
chemical_list: D013739:Testosterone