| Abstract: | Repeated measurements of plasma testosterone (T) were made in 56 male marmosets from the day of birth until 300 days of age and in 44 adults (greater than 3 years). The resulting profile of plasma T during postnatal development shows higher levels during infancy (1-90 days) followed by a nadir between 100 and 170 days and then a progressive rise in T during puberty. Although T levels of up to 21 ng/ml were measured in infant males, mean levels (+/- SEM) were 5.4 +/- 0.6 ng/ml (days 1-10), declining gradually to 1.7 +/- 0.1 ng/ml (days 100-110). No increase in mean T levels between 15 and 100 days was identified, and the onset of puberty was earlier in some males than measured previously in this species. |
