Pineal and associated neuroendocrine rhythms

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Abstract

(1) The mammalian pineal gland exhibits a number of biosynthetic rhythms. (2) Pineal serotonin levels are highest during the day and lowest at night. (3) Conversely, the activity of serotonin N-acetyltransferase, which converts serotonin to N-acetylserotonin, is greatly increased at night over daytime values. (4) As a consequence, N-acetylserotonin content increases in the pineal gland at night as does the product of its metabolism, melatonin. (5) Either indoleamines, such as melatonin, or polypeptides, such as arginine vasotocin, may be the pineal substances which influence the secretion of hormones from other endocrine glands. (6) Besides the obvious circadian rhythms within the pineal gland there are indications that the activity of this organ also changes on a seasonal basis, being more active during the winter than during the summer. (7) One physiological niche of the pineal gland may be to act as an intermediary between seasonal photoperiodic changes and the neuroendocrin reproductive axis. (8) In long day breeders, the pineal is believed tobe most active during the winter and, as a result, its hormonal products suppress sexual physiology. (9) This ensures that animals can only breed during restricted periods of the year.

References (44)

  • J. Axelrod et al.

    Purification and properties of hydroxyindole-O-methyltransferase

    J. biol. Chem.

    (1961)
  • J.D. Dunn et al.

    Effect of stress on circadian periodicity in serum LH and prolactin concentration

    Endocrinology

    (1972)
  • F. Frascini et al.

    Rhythmic phenomena and pineal principles

  • J. Herbert

    Initial observations on pinealectomized ferrets kept for long periods in either daylight or artificial illumination

    J. Endocr.

    (1972)
  • T. Hiroshige et al.

    Sex differences in circadian periodicity of CRF activity in rat hypothalamus

    Neuroendocrinology

    (1973)
  • K. Hoffmann

    The influence of photoperiod and melatonin on testis size, body weight, and pelage colour in the Djungarian hamster (Phodopus sungorus)

    J. comp. Physiol.

    (1973)
  • T. Ito et al.

    Diurnal rhythm in the pineal: its morphological aspects

  • J.J. Jacobs

    The effect of pinealectomy on adrenocortical rhythm in the blinded rat

    Am. J. Anat.

    (1974)
  • J.S. Kizer et al.

    The nyctohemeral rhythm of plasma prolactin: effects of ganglionectomy, pinealectomy, constant light, constant darkness or 6-OH-dopamine administration

    Endocrinology

    (1975)
  • D.C. Klein et al.

    Pineal gland: stimulation of melatonin production by norepinephrine involves cyclic AMP mediated stimulation of N-acetyltransferase

    Adv. Biochem. Psychopharmacol.

    (1970)
  • D.C. Klein et al.

    Adrenergic-adenosine 3′, 5′-monophosphate regulation of serotonin N-acetyltransferase activity and the temporal relationship of serotonin N-acetyltransferase activity to synthesis of 3H-N-acetylserotonin and 3H-melatonin in the cultured rat pineal gland

    J. Pharm. exp. Ther.

    (1973)
  • R.K.-H. Mogler

    Das Endokrine System des syrischen Goldhamster unter Berucksichtizung des Natürlichen und Experimentallen Winterschläf

    Z. Morphol. Oekol. Tiere

    (1958)
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