Summary
In the pineal of 21-day old male Wistar rats hydroxyindole-O-methyl-transferase (HIOMT) activities involved in the synthesis of several 5-methoxyindoles were determined during the night in April, June, October and January. A high HIOMT activity for the synthesis of melatonin/5-methoxytryptophol was determined in the months of January and April. In June and October a decrease was observed. The activity maxima coincide with peaks of activity found for the synthesis of 5-methoxytryptophan. Synthesis of 5-methoxytryptamine occurred only in June and October, whereas the synthesis of 5-methoxyindole-3-acetic acid occurred only in January. From these results it may be concluded that January and April are the most active months of those tested for the melatonin/5-methoxytryptophol synthesis in the rat pineal gland. A possible physiological role of the 5-methoxyindoles other than melatonin and 5-methoxytryptophol is discussed.
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Balemans, M. G. M., Legerstee, W. C., van Benthem, J. Day and night rhythms in the methylation of N-acetylserotonin/5-hydroxytryptophol in the pineal gland of male rats of different ages. J. Neural Transm.45, 265–272 (1979).
Balemans, M. G. M., Noordegraaf, E. M., Bary, F. A. M., van Berlo, M. F. Estimation of the methylating capacity of the pineal gland. With special reference to indole metabolism. Experientia34, 887–888 (1978).
Balemans, M. G. M., van Benthem, J., Legerstee, W. C., de Moree, A., Noteborn, H. J. P. M., Ebels, I.: The influence of some pterins on the circadian rhythmicity of hydroxyindole-O-methyl transferase in the pineal gland of 42 day old male Wistar rats. Reprod. Nutr. Dévelop.20 (in press, 1980).
Frink, R., Krupp, P. P., Young, R. A. Seasonal ultrastructural variations in pinealocytes of the woodchuck, Marmota monax. J. Morphol.158, 91–107 (1978).
Legait, H., Legait, E., Contet-Audonneau, J. L. Données morphométriques de l'épiphyse, de l'organe subfornical et du noyau supra-optique du Muscardin au cours du cycle annuel comparées à celle du Loir et du Lérot. C.R. Seance Soc. Biol.168, 834–837 (1974).
Legait, H., Contet-Audonneau, J. L., Sirjean, D. Données morphometriques sur quelques organes glandulaires intracraniens du Loir (Glis glis). Bull. Assoc. Anat.58, 161 (1974).
McIsaac, W. M., Taborsky, R. G., Farrell, G. 5-Methoxytryptophol: Effect on estrus and ovarian weight. Science145, 63–64 (1964).
Quay, W. B. Circadian rhythm in rat pineal serotonin and its modifications by estrous cycle and photoperiod. Gen. Comp. Endocr.3, 473–479 (1963).
Quay, W. B. Seasonal cycle and physiological correlates of pinealocyte nuclear and nucleolar diameters in the bats, Myotis lucifugus and Myotis sodalis. Gen. Comp. Endocr.29, 369–375 (1976).
Reiter, R. J. Pineal control of a seasonal reproductive rhythm in male golden hamsters exposed to natural daylight and temperature. Endocr.92, 423–430 (1973).
Reiter, R. J. Influence of pinealectomy on the breeding capability of hamsters maintained under natural photoperiod and temperature conditions. Neuroendocr.13, 366–370 (1973/74).
Reiter, R. J., Blask, D. E., Johnson, L. Y., Rudeen, P. K., Vaughan, M. K., Waring, P. J. Melatonin inhibition of reproduction in the male hamster; its dependency on time of day of administration and on an intact and sympathetically innervated pineal gland. Neuroendocr.22, 107–116 (1976).
Reiter, R. J., Rudeen, P. K., Philo, R. C. Influence of chronic melatonin availability on the reproductive quiescent period in male hamsters exposed to natural photoperiods during the winter months. Curr. Stud. Hypothal. Funct.2, 175–182 (1978).
Reiter, R. J., Vaughan, M. K., Waring, P. J. Prevention by melatonin of short day induced atrophy of the reproductive systems of male and female hamsters. Acta Endocr.84, 410–418 (1977).
Roux, M., Richoux, J. P., Cordonnier, J. L. Influence de la photopériode sur l'ultrastructure de l'épiphyse avant et pendant la phase génitale saisonniére chez la femelle du lérot (Eliomys quercinus). J. Neural Transm.41, 209–223 (1977).
Smith, I., Larson-Carter, D. L., Laud, C. A., Leone, R. M., Silman, R. E., Carter, S. J., Francis, P., Mullen, P. E., Hooper, R. J. L., Finnic, M. D. A. 0-acetyl-5-methoxytryptophol-Tentative identification in pineal glands. In: The Pineal Gland of Vertebrates Including Man. Progress in Brain Research (Ariéns Kappers, J., Pevet, P., eds.), Vol. 52, pp. 259–261. Amsterdam-New York: Elsevier/North-Holland Bio-medical Press. 1979.
Thieblot, L., Berthelay, J., Blaise, S. Effets de la mélatonine chez le rat mâle et femelle: I. Action au niveau des gonades et des annexes. Ann. Endocr.27, 65–68 (1966).
Wesson, J. A., Orr, E. L., Quay, W. B., Ginther, O. J. Seasonal relationship between pineal hydroxyindole-O-methyltransferase (HIOMT) activity and reproductive status in the pony. Gen. Comp. Endocr.38, 46–52 (1979).
Wurtman, R. J., Axelrod, J., Chu, E. W. Melatonin, a pineal substance. Effect on rat ovary. Science141, 277–278 (1963).
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Balemans, M.G.M., Bary, F.A.M., Legerstee, W.C. et al. Seasonal variations in HIOMT activity during the night in the pineal gland of 21 day old male wistar rats. J. Neural Transmission 49, 107–116 (1980). https://doi.org/10.1007/BF01249192
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DOI: https://doi.org/10.1007/BF01249192