Sheldon Kapen

Human prolactin - 24-hour pattern with increased release during sleep.

Human prolactin was measured in plasma by radioimmunoassay at 20 minute intervals for a 24-hour period in each of six normal adults, whose sleep-wake cycles were monitored polygraphically. A marked diurnal variation in plasma concentrations was demonstrated, with highest values during sleep; periods of episodic release occurred throughout the 24 hours.

The relationship of sleep and sleep stages to neuroendocrine secretion and biological rhythms in man.

Publisher Summary This chapter reviews the major new observations made regarding the temporal organization of the 24-hour pattern of hypothalamic-pituitary function in regard to sleepwaking function. It discusses the recent application of these results to certain clinical disorders. All the pituitary hormones studied with the technique of frequent plasma sampling have been found to be secreted in an episodic manner throughout the 24-hour day. These hormones have important temporal secretory pattern relationships with the sleepwaking 24-hour cycle. In addition, the sleep stage cyclic pattern during nocturnal sleep is closely related to the timing of several pituitary hormones indicating state control by the central nervous system (CNS) over the timing and amount of secretion under normal physiological conditions. Each system appears to have its own temporal organization and response to manipulations of the sleepwaking cycle, and no single principle or mechanism can be invoked to explain these differing patterns. The concept that a homesotatic steady state or basal level is present for any extended time period of the 24-hour day is clearly not the case. The data suggest that a major mechanism of control takes place by CNS 24-hour temporal programs that initiate secretion independent of existing plasma concentrations under normal stable conditions.

Luteinizing hormone: Changes in secretory pattern during sleep in adult women

Abstract Plasma samples were collected every twenty minutes from each of five normal women and luteinizing hormone was measured by radio-immunoassay. Plasma concentrations of luteinizing hormone were decreased in the first part of the sleep period with the maximum drop occuring during the third hour following stage II onset. Analysis of similar data from a group of five normal men revealed no significant differences in the LH secretory pattern between waking activity and sleep or between the two halves of the sleep period. Analogy was made with the differential capacity of the hypothalamus in males and females to release LH cyclically. Speculation was offered on the possible role of the pineal gland in the sleep-related changes of LH secretion in women.

Pituitary microadenoma and hyperprolactinemia: a cause of unexplained secondary amenorrhea.

The recent development of precise and sensitive radioimmunoassay methods for the measurement of human prolactin has resulted in a large body of data concerning the regulation of this hormone in phy...

Twenty-four-hour patterns of luteinizing hormone secretion in humans: ontogenetic and sexual considerations.

Publisher Summary This chapter discusses the 24-hr patterns of luteinizing hormone secretion in humans. Much progress is made in recent years in understanding factors controlling gonadotropin secretion in humans. This progress is made possible primarily by three technical advances: (1) the development of sensitive and specific assays for LH (luteinizing hormone) and FSH (follicle-stimulating hormone), especially radio immunoassay; (2) frequent blood sampling by techniques that interfere as little as possible with the subjects waking and sleeping activity; and (3) polygraphic recording of the EEG (electroencephalogram), EOG (electrooculogram), and EMG (electromyogram) during sleep so that sleep onset and offset can be precisely determined and correlations can be made with sleep stages. Using the methods enumerated in the foregoing paragraph, we will describe findings from this laboratory which deal with 24-hr LH secretory patterns in men and women from childhood to adulthood. The twenty-four-hour patterns of LH (luteinizing hormone) secretion are characterized by major changes with ontogenetic development and by marked gender differences. Thus, sleeping activity is distinguished during puberty by an augmentation of LH secretion while, conversely, LH secretion decreases during the sleep of adult women. Adult men do not show such sleep-related changes in LH secretion.

Ontogeny of luteinizing hormone and testosterone secretion

Abstract Plasma luteinizing hormone (LH) and testosterone (T) were measured by radioimmunoassay in 9 pubertal boys and 9 sexually mature adult men at 20 min intervals for 24 h. Polygraphic monitoring of sleep was also carried out to precisely identify sleep onset, wakefulness and specific sleep stages. In all 9 pubertal boys, plasma LH showed the characteristic augmentation of secretion synchronous with sleep. This increased LH secretory activity was effective in stimulating increased T secretion during sleep that resulted in uniformly higher mean T concentrations during sleep compared with waking. Plasma LH and T were also measured in 3 of these pubertal boys during acute inversion of the sleep wake cycle. The results showed that plasma LH and T were now augmented during the reversed daytime sleep period; the mean LH and T concentrations were significantly higher than during nocturnal waking. Measurement of LH and T in the 9 adult men showed episodic secretion of both hormones during waking and sleep periods with no consistent augmentation of either hormone during sleep.

ONTOGENY OF LUTEINIZING HORMONE AND TESTOSTERONE SECRETION

Plasma luteinizing hormone (LH) and testosterone (T) were measured by radioimmunoassay in 9 pubertal boys and 9 sexually mature adult men at 20 min intervals for 24 h. Polygraphic monitoring of sleep was also carried out to precisely identify sleep onset, wakefulness and specific sleep stages. In all 9 pubertal boys, plasma LH showed the characteristic augmentation of secretion synchronous with sleep. This increased LH secretory activity was effective in stimulating increased T secretion during sleep that resulted in uniformly higher mean T concentrations during sleep compared with waking. Plasma LH and T were also measured in 3 of these pubertal boys during acute inversion of the sleep wake cycle. The results showed that plasma LH and T were now augmented during the reversed daytime sleep period; the mean LH and T concentrations were significantly higher than during nocturnal waking. Measurement of LH and T in the 9 adult men showed episodic secretion of both hormones during waking and sleep periods with no consistent augmentation of either hormone during sleep.