The rhythmic melatonin synthesis in the pineal gland is one of the most extensively studied circadian rhythms in vertebrates. Light is the dominant environmental factor controlling this process. Light at night acutely suppresses pineal melatonin content and activity of serotonin N-acetyltransferase (AANAT; the key and penultimate enzyme in the hormone biosynthetic pathway). In addition, pulses ...

Melatonin, a pineal hormone is known to regulate rhythmic behavior of mammals. Its ubiquitous presence, established recently has brought into focus several health-promoting benefits of this molecule. However, till date, melatonin has been less utilized from its nutraceutical and functional point of view. This paper reviews the chemistry, chemical synthesis, metabolism of melatonin; its sources ...

Many temperate zone animals adapt to seasonal changes by altering their physiology. This is mediated in large part by endocrine signals that encode day length and regulate energy balance and metabolism. The objectives of this study were to determine if the daily patterns of two important hormones, melatonin and cortisol, varied with day length in captive brown bears (Ursus arctos) under anesthe...

[email protected] INTRODUCTION: The observation that an experimental pinealectomy in newborn chickens leads to a spinal deformity similar to idiopathic scoliosis in humans initiated a new neuroendocrine hypothesis for the cause of idiopathic scoliosis. A deficiency of melatonin, which is the principal product of the pineal gland, was believed to be responsible for this deformity, because b...