Paul R. Gouin

Nocturnal Increase of Plasma Testosterone in Men: Relation to Gonadotropins and Prolactin

The nocturnal increase of plasma testosterone (T) in adult men has been well established. Luteinizing hormone (LH) does not show a similar increase throughout the night, whereas prolactin (PRL) does, suggesting the possibility of other hormone influence on T secretion. To investigate this possibility, 8 young adult men were studied for 4 consecutive nights in the sleep laboratory (2 nights adaptation, 2 nights blood sampling), by blood samples taken every 30 min during the 8-h sleep period, for measurement of LH, follicle stimulating hormone (FSH), PRL, and T. LH and FSH were secreted episodically, with little or no change in baseline levels during the night. PRL and T also were secreted episodically, but their baseline levels increased as the night progressed. Both LH and PRL had maximum within-subject correlations (averages equal +0.35 and +0.48 respectively) with T when they led T by 60 min. Within-subject correlations done on first differences (to remove the effect of slow trends) were near zero. LH and PRL had larger correlations with T than did FSH, for both calculations. These data suggest that both LH and PRL levels precede T levels by about 60 min. PRL thus may participate in the regulation of nocturnal T secretion in adult men.

Selective neuroendocrine effects of low-dose haloperidol in normal adult men.

The neuroendocrine effects of haloperidol, usually reported as side effects of this drug when given in antipsychotic doses, have not been systematically investigated. In the present study five normal adult men were administered saline and two doses of haloperidol (0.25 mg, 0.5 mg) intramuscularly in a double-blind randomized block design. The anterior pituitary hormones GH, LH, FSH, and PRL were measured in blood samples taken every 20 min for several hours thereafter.The low doses of haloperidol used have been shown by others to alter the human EEG; in our subjects these doses produced no objective or subjective clinical effects. There were no drug related changes in GH, LH, or FSH. PRL, however, showed a prompt, statistically significant, dose-related increase in plasma levels, with a return to baseline within 5h.Haloperidol has strong dopamine-blocking effects, and the hypothalamic inhibitory mechanism for PRL release is believed to be dopamine-mediated. The results of this study suggest that haloperidol may have utility in low doses primarily for its hypothalamic neuroendocrine effects, and that dose-related PRL release may be a useful paradigm for comparing dopamine-blocking antipsychotic agents in humans.

Secretion of hormones influencing water and electrolyte balance (antidiuretic hormone, aldosterone, prolactin) during sleep in normal adult men.

&NA; Renal conservation of electrolytes and water occurs normally during sleep. Antidiuretic hormone (ADH), aldosterone (ALDO), and prolactin (PRL) are hormones that may have interactive effects on kidney function. The availability of a radioimmunoassay for ADH as well as for ALDO and PRL permitted the study of the simultaneous secretion patterns of these three hormones during all‐night sleep in eight normal young adult men, by blood sampling every 20 min from 2300 to 0700 on two consecutive night. ADH, ALDO, and PRL all appeared to be secreted episodically. The pulsatile release of ADH was random, and average plasma ADH levels were unchanged during the night. ALDO and PRL, on the other hand, had an approximately 90‐min secretion rhythm, and average plasma concentrations of both hormones consistently increased during the hours of sleep. Average plasma sodium concentration was constant throughout the night. The nocturnal increase in plasma ALDO may be responsible for the normal reduction of urine sodium excretion during the night. The concomitant increase in plasma PRL might synergize with ALDO in influencing the renal retention of sodium, but PRL alone has little apparent effect on human kidney function. REM sleep‐related decreases in urine flow have been noted both in humans and in monkeys, but ADH secretion was not REM related in out subjects. Autonomic activation during REM is one possible explanation for decreased urine flow during this stage of sleep.

The neuroendocrinology of human sleep

Abstract Sleep consists of several distinct patterns of CNS activation, including synchronized or slow wave of sleep and desynchronized or rapid eye movement sleep. Specific areas of the brain as well as specific biogenic amine neurotransmitters appear to be responsible for the periodic shifts between sleep stages. Hypothalamic regulation of the anterior pituitary gland also is influenced by the same biogenic amine neurotransmitters, and the episodic release patterns of the anterior pituitary hormones suggest prominent CNS influences. This review considers the relationship of these hormone release patterns to the circadian sleep-wake cycle and to sleep staging within the sleep period itself.

Lutenizing hormone, follicle stimulating hormone, and growth hormone secretion in normal adult men during sleep and dreaming.

&NA; The patterns of LH, FSH and GH release during all‐night sleep were studied in 16 normal young adult men, sampled on two consecutive nights. The release of both gonadotropins occurred in random, unrelated peaks that showed no consistency between subjects or from night to night in the same subject. No circadian or ultradian rhythm was discernible for either LH or FSH. When analyzed by sleep stages, LH levels showed a modest but significant increase (14%) during REM sleep compared to the other stages of sleep. FSH levels, on the other hand, showed no clear relationship to sleep stages. Growth hormone did show the usual marked increase coincident with the onset of slow wave sleep.

Antidiuretic Hormone: Episodic Nocturnal Secretion in Adult Men

Nocturnal release of antidiuretic hormone (ADH) in eight young adult men occurred in a pulsatile, episodic fashion with no consistency from night to night in the same subject. There was no discernible relationship between ADH release and plasma sodium levels, sleep stages, or time of night.

Antidiuretic hormone secretion during sleep in adult men

Publisher Summary Studies of nocturnal sleep EEG stages and plasma growth hormone (GH) and cortisol levels (used as indices of central nervous system (CNS) function) were performed in subjects with endogenous or exogenous elevation of plasma corticosteroid or ACTH levels, and in patients with hypothalamic tumors. These studies were designed to determine if there was any evidence of altered CNS function that was unique to Cushings disease, independent of any effects of hypercortisolemia per se. of the adrenal adenoma suggests, however, that cortisol excess also plays some role in the observed sleep EEG and GH changes. The presence of normal sleep EEG stages in 4 patients with Cushings disease who have subsequently developed Nelsons syndrome of 1-9 years duration additionally suggests a role of this peptide in the genesis of sleep EEG stages.

THE NEUROENDOCRINOLOGY OF HUMAN SLEEP

Sleep consists of several distinct patterns of CNS activation, including synchronized or slow wave sleep and desynchronized or rapid eye movement sleep. Specific areas of the brain as well as specific biogenic amine neurotransmitters appear to be responsible for the periodic shifts between sleep stages. Hypothalamic regulation of the anterior pituitary gland also is influenced by the same biogenic amine neurotransmitters, and the episodic release patterns of the anterior pituitary hormones suggest prominent CNS influences. This review considers the relationship of these hormone release patterns to the circadian sleep-wake cycle and to sleep staging within the sleep period itself.