Summary
Adult rats (Rattus norvegicus) were subjected to continuous light or control conditions (14 hours light/day) for six weeks or longer, and quantitative cytological and metabolic studies were made of the pineal organs. After 11 weeks of continuous light, the pineal parenchymal cell's largest nucleolar eosinophilic mass is significantly reduced in diameter, especially in the medulla of the organ. Evidence of metabolic inhibition includes reduction of pineal glycogen content, succinic dehydrogenase activity, and respiration in the absence of exogenous substrates. Pineal ATP content, P32-phosphate uptake and 5-hydroxy indole acetic acid content did not appear to be affected. Pineal serotonin content and melatonin-forming activity in the continuously lighted animals were measured but could not be interpreted metabolically, due to the diurnal fluctuations of these in control animals. Results provided here and elsewhere suggest that pineal inhibition by continuous light involves primarily the citric acid cycle, the accumulation of metabolites and lipid, and the synthesis of protein.
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Literature
Ariëns Kappers, J.: The development, topographical relations and innervation of the epiphysis cerebri in the albino rat. Z. Zellforsch. 42, 163–215 (1960).
Brewer, G. F., and W. B. Quay: Pineal and hypophyseal phosphate uptake after castration and administration of sex hormones. Proc. Soc. exp. Biol. (N.Y.) 98, 361–364 (1958).
Dixon, M.: Manometric methods as applied to the measurement of cell respiration and other processes. Cambridge, England: University Press 1952.
Fiske, V. M., G. K. Bryant and J. Putnam: Effect of light on the weight of the pineal in the rat. Endocrinology 66, 489–491 (1960).
Fiske, V. M., J. Pound and J. Putnam: Effect of light on the pineal organ in hypophysectomized, gonadeotomized, adrenalectoimized or thiouracil-fed rats. Endocrinology 71, 130–133 (1962).
Krisman, C.: A method for the colorimetric estimation of glycogen with iodine. Analyt. Biochem. 4, 17–23 (1962).
Long, C., E. J. King and W. M. Sperry (editors): Biochemist's handbook. Princeton, New Jersey: D. van Nostrand Co. Inc. 1961.
Miline, R.: La part de l'épiphyse dans le syndrome d'adaptation. Congr. Nat. des Sci. Med., Ed. de l'Acad. Repub. Pop. Roumaine 421–444 (1957).
Mogler, R. K.-H.: Das Endokrine System des Syrischen Goldhamsters (Mesocricetus auratus auratus Waterhouse) unter Berücksichtigung des natürlichen und experimentellen Winterschlafs. Z. Morph. u. ökol. Tiere 57, 267–308 (1958).
Nešić, Lj.: Contribution à l'étude du rythme saisonnier de la glande pinéale de brebis. Acta anat. (Basel) 59, 376–377 (1962).
Pflugfelder, O.: Physiologie der Epiphyse. Verh. dtsch. zool. Ges. 53–75 (1956).
Quay, W. B.: Volumetric and cytologic variation in the pineal body of Peromyscus leucopus (Rodentia) with respect to sex, captivity and day-length. J. Morph. 98, 471–495 (1956).
: Experimental modifications and changes with age in pineal succinic dehydrogenase activity. Amer. J. Physiol. 196, 951–955 (1959).
: Reduction of mammalian pineal weight and lipid during continuous light. Gen. comp. Endocr. 1, 211–217 (1961).
: Metabolic and cytologic evidence of pineal inhibition by continuous light. Amer. Zool. 2, 550 (1962).
: Differential extractions for the spectrophotofluorometric measurement of diverse 5-hydroxy- and 5-methoxyindoles. Analyt. Biochem. 5, 51–59 (1963a).
: Pineal and ependymal respiration with diverse substrates and inorganic ions. Amer. J. Physiol. 204, 245–250 (1963b).
: Circadian rhythm in rat pineal serotonin and its modifications by estrous cycle and photoperiod. Gen. comp. Endocr. 1, 3 (1963c).
, and A. Halevy: Experimental modification of the rat pineal's content of serotonin and related indole amines. Physiol. Zool. 35, 1–7 (1962).
Roth, W. D., R. J. Wurtman and M. D. Altschule: Morphologic changes in the pineal parenchyma cells of rats exposed to continuous light or darkness. Endocrinology 71, 888–892 (1962).
Sirlin, J. L.: The nucleolus. Progr. Biophys. 12, 27 (1962).
Strehler, B. L., and J. R. Totter: Determination of ATP and related compounds: firefly luminescence and other methods. Meth. biochem. Anal. 1, 341–356 (1954).
Umbreit, W. W., R. H. Burris and J. P. Stauffer: Manometric techniques. Minneapolis: Burgess Publ. Co. 1957.
Wurtman, R. J., W. Roth, M. D. Altschule and J. J. Wurtman: Interactions of the pineal and exposure to continuous light on organ weights of female rats. Acta endocr. (Kbh.) 36, 617–624 (1961).
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This investigation was supported by grant GM-05219 from the National Institutes of Health, U.S. Public Health Service.
I am grateful to Mrs. Virginia Green Bowers, Mrs. Ann Richards, Mr. Peter Charles Baker and Mr. Jorge Antonio Alvarado for laboratory assistance, and to Dr. Richard Strohman and Mr. David Epel, for advice on the determination of ATP.
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Quay, W.B. Cytologic and metabolic parameters of pineal inhibition by continuous light in the rat (Rattus norvegicus) . Z. Zellforsch. 60, 479–490 (1963). https://doi.org/10.1007/BF00336620
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DOI: https://doi.org/10.1007/BF00336620