Patterns of pulsatile luteinizing hormone secretion before and during the onset of puberty in boys: a study using an immunoradiometric assay.
To study spontaneous pulsatile LHRH/LH secretion around the onset of puberty, nocturnal plasma LH was measured by means of a highly sensitive immunoradiometric assay in 30 boys (aged 5.6-16.8 yr) investigated for potential problems with growth and/or development. Blood was withdrawn at 10- to 20-min intervals from 2000-0800 h. Pulse analysis was accomplished by a computerized peak detection algorithm. Pituitary and gonadal responsiveness was assessed by a standard exogenous LHRH challenge and testosterone. Subsequent clinical progress was monitored for a mean duration of 2.08 +/- 0.16 yr and used as the basis for classifying patients retrospectively into three groups: 1) prepubertal (n = 14), 2) peripubertal (n = 11), and 3) pubertal (n = 5). LH pulses were undetectable in 9 and present in 5 prepubertal subjects, the youngest of whom was aged 7.3 yr. In peripubertal and pubertal individuals, 2-7 LH pulses/12 h were detectable. LH pulses were detectable before sleep by midpuberty (Tanner stage 3). There was a highly significant (P less than 0.0001) increase in LH/LHRH pulse frequency from 0.93 +/- 0.38 to 4.55 +/- 0.43/12 h (mean +/- SEM) between the prepubertal and peripubertal groups and a further increase to 6.20 +/- 0.37/12 h in the pubertal group. LH pulse amplitude remained under 1.0 U/L in both the prepubertal and peripubertal groups and only increased significantly to 2.02 +/- 0.17 U/L in pubertal boys. Response to LHRH increased significantly between the prepubertal (2.47 +/- 0.49 U/L) and peripubertal (6.53 +/- 2.02 U/L) patients. T increased significantly at each stage, with the greatest rise between the peripubertal and pubertal stages.(ABSTRACT TRUNCATED AT 250 WORDS)
Wu
F C
FC
Medical Research Council Reproductive Biology and Human Genetics Unit, Edinburgh, Scotland, United Kingdom.
Butler
G E
GE
Kelnar
C J
CJ
Sellar
R E
RE
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm; D004393:Dwarfism, Pituitary / Q000097:blood; D007987:Gonadotropin-Releasing Hormone / Q000097:blood* / Q000378:metabolism; D006801:Humans; D015592:Immunoradiometric Assay; D007986:Luteinizing Hormone / Q000097:blood* / Q000378:metabolism; D008297:Male; D011446:Prospective Studies; D011627:Puberty / Q000097:blood*; D011628:Puberty, Delayed / Q000097:blood; D012741:Sexual Maturation; D013739:Testosterone / Q000097:blood
D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D007986:Luteinizing Hormone