Summary
Although it is generally known that light strongly influences N-acetyltransferase activity and melatonin production in the pineal gland, little information is available concerning morphological changes following light exposure. As exposure of rats to a short light pulse at night rapidly depresses melatonin synthesis, we decided to determine whether this experimental condition produces rapid changes in the pinealocyte organelles. A 30-min light pulse at night (six hours after lights out) provoked rapid changes in the relative volumes of some pinealocyte organelles. The volume fractions of mitochondria, Golgi apparatus and lipid droplets, and the numbers of dense-core vesicles and “synaptic” ribbons decreased, whereas the volume fraction of lysosomes increased. There were no differences in the volumes of granular endoplasmic reticulum and vacuoles containing flocculent material in those animals exposed to light compared with control animals. These results indicate that a short light pulse at night causes ultrastructural changes that can be interpreted as morphological features of diminished activity of pinealocytes.
References
Arendt J (1985) Mammalian pineal rhythms. In: Reiter RJ (ed) Pineal Research Reviews. Vol 3, Alan R. Liss, Inc., New York, pp 161–213
Ebadi M (1984) Regulation of synthesis of melatonin and its significance to neuroendocrinology. In: Reiter RJ (ed) The Pineal Gland. Raven Press, New York, pp 1–37
Illnerová H, Vaněček J (1979) Response of rat pineal N-acetylserotonin transferase to one min light pulse at different night times. Brain Res 167:431–434
Illnerová H, Vaněček J (1982) Two-oscillator structure of the pacemaker controlling the circadian rhythm of N-acetyltransferase in the rat pineal gland. J Comp Physiol 145:539–548
Illnerová H, Vaněček J (1984) Circadian rhythm in inducibility of rat pineal N-acetyltransferase after brief light pulses at night: control by a moving oscillator. J Comp Physiol A 154:739–744
Illnerová H, Vaněček J (1985) Complex control of the circadian rhythm in pineal melatonin production. In: Mess B, Ruzsas Cs, Tima L, Pévet P (ed) The Pineal Gland. Current State of Pineal Research, Akademiai Kiado, Budapest pp 137–153
Illnerová H, Vaněček J (1986) Effect of light on the N-acetyltransferase rhythm in the rat pineal gland. In: Reiter RJ and Karasek M (ed) Advances in Pineal Research, Vol 1, John Libbey, London Paris, pp 69–76
Illnerová H, Backstrom M, Saaf J, Wetterberg L, Vangbo B (1978) Melatonin in the rat pineal gland and serum; rapid parallel decline after light exposure at night. Neurosci Lett 3:189–193
Illnerová H, Vaněček J, Krěček J, Wetterberg L, Saaf J (1979) Effect of one minute exposure to light at night in rat pineal serotonin N-acetyltransferase and melatonin. J Neurochem 32:673–675
Karasek M (1983) Ultrastructure of the mammalian pineal gland: its comparative and functional aspects. In: Reiter RJ (ed) Pineal Research Reviews. Vol 1, Alan R Liss, Inc., New York, pp 1–48
Karasek M (1986) Quantitative aspects of the ultrastructure of the mammalian pinealocyte. In: Reiter RJ and Karasek M (ed) Advances in pineal research. Vol 1, John Libbey, London Paris, pp 9–18
Karasek M, Jameson EW, Jr, Hansen JT, Reiter RJ (1983) Ultra structure of the pineal gland of the brush mouse (Peromyscus boylei): influence of long and short photoperiod. J Neural Transm 56:293–301
Karasek M, Matthews SA, King TS, Reiter RJ (1986) Effects of long and short photoperiod on the ultrastructure of pinealocytes of the cotton rat (Sigmodon hispidus). J Pineal Res 3:323–330
Klein D (1979) Circadian rhythms in the pineal gland. In: Kieger DT (ed) Endocrine Rhythms. Raven Press, New York, pp 203–223
Klein DC, Weller J (1972) Rapid light-induced decrease in pineal serotonin N-acetyltransferase activity. Science 1977:532–533
Maitra SK, Huesgen A, Vollrath L (1986) The effects of short pulses of light at night on numbers of pineal “ synaptic” ribbons and serotonin N-acetyltransferase activity in male SpragueDawley rats. Cell Tissue Res 246:133–136
Pévet P (1977) On the presence of two different populations of pinealocytes in the mammalian pineal gland. J Neural Transm 40:389–404
Pévet P (1979) Secretory processes in the mammalian pinealocytes under natural and experimental conditions. Prog Brain Res 52:149–194
Pévet P, Karasek M (1977) Are the pineal active compounds of mammals proteinaceous in nature? An ultrastructural contribution. Acta Med Pol 18:351–353
Reiter RJ (1986) Pineal melatonin production: photoperiodic and hormonal influences. In: Reiter RJ, Karasek M (ed) Advances in Pineal Research, Vol 1, John Libbey, London Paris, pp 77–87
Reiter RJ, Rudeen PK, Banks AF, Rollag MD (1979) Acute effects of unilateral or bilateral superior cervical ganglionectomy on the rat pineal N-acetyltransferase activity and melatonin content. Experientia 35:691–692
Rollag MD, Welsh MG, Klein DC (1984) Effect of acute light exposure upon melatonin content, NAT activity, and nuclear volume in the gerbil pineal complex. J Pineal Res 1:339–347
Vollrath L (1981) The Pineal Organ. Springer, Berlin Heidelberg New York
Waldhauser F, Wurtman RJ (1983) The secretion and action of melatonin. In: Litwack G (ed) Biochemical Actions of Hormones. Vol 10, Academic Press, New York pp 187–225
Weibel RR (1979) Stereological Methods. Vol 1, Academic Press, London
Wilkinson M, Arendt J, Bradtke J, de Ziegler D (1977) Determination of a dark-induced increase in pineal N-acetyltransferase activity and simultaneous radioimmunoassay of melatonin in pineal, serum and pituitary tissue of the male rat. J Endocrinol 72:243–244
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Karasek, M., Marek, K. & Pévet, P. Influence of a short light pulse at night on the ultrastructure of the rat pinealocyte: a quantitative study. Cell Tissue Res. 254, 247–249 (1988). https://doi.org/10.1007/BF00220041
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DOI: https://doi.org/10.1007/BF00220041