In spite of concerted efforts by many investigators, the function of the pineal gland remains an enigma. Certainly un­ derstanding has progressed since the ob­ servations of the philosopher Herophilus who thought that the pineal was a sphinc­ ter to control the flow of thought from the ventricles or Descartes’ proclamation that the pineal was the “ Seat of the Soul.” U n­ fortunately, no invest...

The demonstration of the hormone mclatonin (N-acetyl-Bmethoxytryptamine) in bovine pineal gland (1) prompted a study of the enzymes involved in its formation and metabolism. In preliminary studies (2, 3) we described an enzyme, hydroxyindole-O-methyl transferase, in the pineal gland of cows, that catalyzes the 0-methylation of N-acetyl-serotonin to melatonin. This paper describes the purificati...

The demonstration of the hormone mclatonin (N-acetyl-Bmethoxytryptamine) in bovine pineal gland (1) prompted a study of the enzymes involved in its formation and metabolism. In preliminary studies (2, 3) we described an enzyme, hydroxyindole-O-methyl transferase, in the pineal gland of cows, that catalyzes the 0-methylation of N-acetyl-serotonin to melatonin. This paper describes the purificati...

Our perception of pineal gland function has attained new dimensions during the last decade. The gland is active throughout the life of an individual and secretes melatonin, the major pineal hormone, and many indoles and polypeptides. The secretion of pineal gland is regulated not only by sympathetic nerve fibers but by other central pinealopetal projections also. Many neurotransmitter-receptor ...

mitochondrial dysfunction is one of the main causative factors in a wide variety of complications such as neurodegenerative disorders, ischemia/reperfusion, aging process, and septic shock. decrease in respiratory complex activity, increase in free radical production, increase in mitochondrial synthase activity, increase in nitric oxide production, and impair in electron transport system and/or...

The avian pineal gland contains both circadian oscillators and photoreceptors to produce rhythms in biosynthesis of the hormone melatonin in vivo and in vitro. The molecular mechanisms for melatonin biosynthesis are largely understood, but the mechanisms driving the rhythm itself or the photoreceptive processes that entrain the rhythm are unknown. We have produced cDNA microarrays of pineal gla...

Melatonin (N-acetyl-5-methoxytryptamine) is a hormone produced by the pineal gland in the brain in response to darkness. Melatonin is made available when tryptophan is converted to serotonin and then enzymatically converted to melatonin in the pineal gland. Serum levels are low during the day, with peak levels occurring from 2-4 am.

The mammalian pineal gland is rich in serotonin content and this amine is present in high concentration within the sympathetic nerve endings of this organ (Quay and Halevy, 1962; Bertler et al., 1963). Sympathetic denervation of the pineal gland results in a 50% decrease in its serotonin content (Bertler et al., 1963; Pellegrino de Iraldi et al., 1963). Recently it has been demonstrated that th...

The pineal gland in ma.i is an active endocrine gland throughout life (Wurtman et al., 1964 ; Tapp & Huxley, 1972 ; Cardinali, 1974 ; Reiter et al., 1975 ; Reiter, 1978). It elaborates several hormones with precise rhythmicity. The chronobiological aspects of the mammalian pineal gland have been clearly brought out by Reiler (198!) defining the circadian rhythms in indole metabolism within the ...