The demonstration that luteinizing hormone (LH) release from the pituitary is episodic rather than constant raises fundamental questions regarding the physiologic control of pulsatile LH secretion and its possible alteration in patients with gonadal disorders. To evaluate this mode of LH secretion, quantitative means of analyzing LH pulse amplitude, frequency, shape, and area were established and utilized to study normal subjects and patients with disorders of gonadotropin secretion. Similar patterns of LH secretion were observed in normal men, in women during the follicular phase of the menstrual cycle, and in patients with hyper- and hypogonadotropism, hirsuitism, and amenorrhea (mean pulse amplitude 39-179% from nadir to peak, frequency 2.7-3.9 secretory spikes/6 h). These observations suggested that the pattern of LH secretion is similar in both normal individuals and in those with a variety of pathologic conditions. By contrast, the pattern of pulsatile secretion appeared to differ in the following conditions. LH pulses of higher amplitude (333±170%) and lower frequency (1.6±0.24 SEM/6 h) characterized the secretory patterns of women during the luteal phase of the menstrual cycle, suggesting that gonadal steroids may modulate LH pulses. LH pulses of low amplitude (26±2.1%) and frequency (1.3±0.36/6 h) were observed in women with anorexia nervosa.
R. J. Santen, C. W. Bardin
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