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Abstract:
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Men with idiopathic azoo-oligospermia and selective elevations of
follicle-stimulating hormone (FSH) levels have evidence for decreased
luteinizing hormone-releasing hormone (LH-RH) pulse frequency. We assessed
whether increasing the frequency of pulsatile LH-RH stimulation can lower
FSH levels in such men. We administered 5.0 microgram of pulsatile LH-RH
subcutaneously at intervals of 30, 60, and 120 minutes for 1 week to four
men who had azoospermia, elevated FSH levels, and normal LH and
testosterone (T) levels. The order of administration was varied among
subjects. Frequent blood samples were obtained for 6 hours before LH-RH
treatment and during the last 6 hours of each regimen. Before LH-RH
treatment, the FSH levels (mean +/- standard error of the mean) were 359
+/- 18 ng/ml (normal range, 30 to 230 ng/ml). During LH-RH treatment, FSH
levels progressively declined from 397 +/- 68 ng/ml to 237 +/- 70 ng/ml to
175 +/- 43 ng/ml as the frequency of administration increased from every
120 to 60 to 30 minutes, respectively (P less than 0.05). Unlike the FSH
levels, which showed a progressive decline, LH, T, and estradiol levels
showed no consistent relationship to LH-RH pulse frequency. We conclude
that (1) in men with idiopathic azoospermia and elevated FSH levels, it is
possible to decrease FSH levels by increasing the frequency of pulsatile
LH-RH stimulation; (2) this decline does not appear to be a result of
changes in steroid feedback or pituitary down-regulation; and (3) the
frequency of pulsatile LH-RH stimulation can differentially modulate LH
and FSH secretion by the pituitary gland. |