Ontogeny of pulsatile gonadotropin releasing hormone secretion from midchildhood, through puberty, to adulthood in the human male: a study using deconvolution analysis and an ultrasensitive immunofluorometric assay.
Level 4 - case-series / case-control
Cross-sectional observational physiological study comparing four developmental cohorts
PubMed 8626838 · doi:10.1210/jcem.81.5.8626838
What was done
The authors evaluated nocturnal (2000–0800 h) pulsatile LH secretion to indirectly assess hypothalamic GnRH pulse generator activity across male development. Plasma LH was measured using an ultrasensitive immunofluorometric assay (DELFIA) and analyzed via deconvolution analysis across four cross-sectional cohorts: 16 boys in midchildhood (mean age 6.6 ± 0.3 yr), 8 prepubertal boys (12.0 ± 0.3 yr), 8 early pubertal boys (14.3 ± 0.4 yr), and 8 young fertile adult men (32.6 ± 1.6 yr).
What was found
Sleep-entrained LH secretory bursts were present in midchildhood, with the initial increase occurring ~2 years before clinical puberty. From midchildhood to adulthood, the LH production rate increased 39-fold. LH pulse frequency increased 1.8-fold from midchildhood to pubertal onset and remained constant thereafter into adulthood. Amplification of LH mass secreted per burst accounted for 91.7% of the total increase in plasma LH concentration from childhood to adulthood. Secretory burst duration and apparent LH half-life did not change across age groups, whereas the nocturnal/sleep-associated rhythm was lost in young adulthood.
Why it matters
This study shows that male puberty is primarily driven by amplitude amplification of an existing GnRH pulse generator rather than de novo initiation of pulsatility, with pulse frequency largely restrained once pubertal onset occurs.
Limits
The study is cross-sectional rather than longitudinal, limiting assessment of individual developmental trajectories. Sample sizes are small (n = 8 for three of the four groups). Hypothalamic GnRH dynamics were inferred indirectly from peripheral LH measurements, and sampling was restricted to a 12-hour overnight window.
Cited by
- context Gonadotropins FSH and LH are released from the brain during the early morning hours.