We have studied gonadotropin and inhibin pulsatility in 88 normal pubertal children. We completed studies of LH, FSH, inhibin and testosterone pulsatility in 10 fully pubesced males and 14 prepubertal males. We showed that inhibin release is pulsatile, that the mean levels of inhibin increase in males as they progress through puberty. We also showed that the number of peaks of inhibin in a given sampling period does not increase during puberty though the peak height does increase. This pattern of increase of peak height, but not peak number, is the same as that for FSH. LH and testosterone peak numbers and peak heights increase throughout puberty. We have shown that inhibin increases in response to an intravenous bolus of LHRH. It appears that the mean levels of inhibin are different in males and females. We are currently working with the statisticians to develop a method for analyzing coincidence of pulses of the hormones studied. We began to study how inhibin, testosterone and gonadotropin pulsatility changes during the day in a cross-sectioned study and how release of these hormones changes in a population of children followed longitudinally throughout puberty. We have begun to study children with abnormalities of puberty, including gynecomastia, delayed puberty and cryptorchidism.