The pineal and psychiatry: a review

The pineal body in man is an active endocrine gland throughout life. Historically the gland has been associated with speculation on the nature of mind and its disorders. Modern research is now demonstrating it to be an endocrine gland capable of affecting the brain and behaviour. The implications for future research into this aspect of pineal function are discussed in the context of a critical review of the current literature.

A study of indoles which inhibit pineal antigonadotrophic activity in male hamsters

Blinding adult male golden hamsters led to involution of the testes and accessory sex organs (seminal vesicles and coagulating glands) and to a regression in pituitary prolactin levels within 8 weeks. The subcutaneous implantation of either melatonin or 6-hydroxymelatonin (1 mg/wk in beeswax) prevented the atrophy of the reproductive organs and the decrease in the stores of pituitary prolactin. Two other indoles, N-acetylserotonin and 5-hydroxytryptophol, failed to counteract the reproductive effects of blinding. Both melatonin and 6-hydroxymelatonin significantly elevated plasma LH titers.

Effects of the pineal gland in unilaterally adrenalectomized rats

The following experiments were undertaken to determine the effects that the pineal secretory substance might have on compensatory adrenal hypertrophy and corticosterone plasma levels in unilaterally adrenalectomized rats. It was demonstrated that blinded animals and animals administered with a bovine pineal extract exhibited a reduction in the percentage compensatory adrenal hypertrophy, a reduction in the thickness of the zona fasciculata, and a reduction in the plasma corticosterone level. These inhibitory effects were reversed by pinealectomy and ACTH injections, suggesting that the pineal gland, acting as a mediator for environmental lighting, might influence synthesis and/or release of ACTH.