ABSTRACT
Prostaglandins (PG) occur in most mammalian tissues and are released on tissue stimulation or activation. As the central actions of PGs, pharmacological and/or physiological effects on behavior, body temperature, food intake, analgesia, pituitary hormone secretion, respiration, and spinal cord reflex have been documented. The circadian differences may lead to the following assumption: under the condition that physiologically required sleep is satisfied, the somnogenic activity of an excessive supply of PGD2 might be cancelled by the endogenous regulatory mechanisms, and no supranormal excess sleep is induced by the exogenously supplemented PGD2. The presence of somnogenic and antisomnogenic PGs in the brain leads to the question as to whether or not the inhibition of PG synthesis in vivo provokes any change in the amount of sleep. Ueno quantified the amounts of PGs by radioimmunoassay in saliva from healthy humans and patients with the major depressive disorder, the minor depressive disorder, and neurotic disorders of various kinds.
