Comparative aspects of the pineal/melatonin system of poikilothermic vertebrates

  title={Comparative aspects of the pineal/melatonin system of poikilothermic vertebrates},
  author={Ana Maria Caliman Filadelfi and A M Castrucci},
  journal={Journal of Pineal Research},
Abstract: The pineal gland of poikilothermic vertebrates originates as an evagination from the diencephalic roof between the habenular and the posterior commissures, and associates with a parapineal organ to form the so‐called pineal complex. The pinealocytes may be photosensitive, secretory or intermediate cells between both. Melatonin, the indoleamine secreted by the pineal, exhibits a circadian secretory rhythm that conveys environmental information to the organism. The peak melatonin… 
Immunocytochemical observations on pineal organ and retina of the Antarctic teleosts Pagothenia borchgrevinki and Trematomus bernacchii
It is concluded that the pineal organs of both species, at least during the austral summer, exhibit signs of being directly photo-sensitive.
Melatonin does not affect the black pigment migration in the crab Neohelice granulata
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The results indicate clearly that the circadian rhythm exists in the melatonin synthesis of the pineal body in Zacco temmincki.
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Type II Opsins in the Eye, the Pineal Complex and the Skin of Xenopus laevis: Using Changes in Skin Pigmentation as a Readout of Visual and Circadian Activity
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Melatonin as a Hormone: New Physiological and Clinical Insights.
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This chapter discusses in detail the various aspects of melatonin with its key role in the body and how this versatile hormone and its receptors work in a synchronized way to alter the pathophysiological processes of the body according to the biological clock and circadian rhythm.
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Melatonin, a hormone whose importance was not recognized until relatively recently, has the possibility, to serve as a transducer between the ambient light changes and the rhythm of the cycles of various biological processes (circadian or seasonal rhythms), among other functions.


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It is indicated that the pineal organ in catfish is involved in the regulation of locomotor activity rhythms and in some aspects of osmoregulation and Circadian rhythms in plasma cortisol, osmolality and electrolytes, but there were no significant differences in the mesor values of plasma cortisol.
Pinopsin is a chicken pineal photoreceptive molecule
Cloned chicken pineal cDNA encoding the photoreceptive molecule is cloned and it is confirmed that it is a pineal photosensor and named pinopsin, indicating a similarity between retinal rod cells and pinealocytes in the phototransduction pathway.
Interactions of the pineal hormone melatonin with oxygen-centered free radicals: a brief review.
  • R. Reiter
  • Biology
    Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas
  • 1993
It is found that melatonin is a very potent hydroxyl radical scavenger and there is evidence that it may be bound in the nucleus thereby providing on-site protection to DNA.
Distribution of melatonin in mammalian tissues: The relative importance of nuclear versus cytosolic localization
The administration of exogenous melatonin resulted in a marked increase in the nuclear melatonin content without a concomitant change in the cytosolic fraction, and its location in the nucleus suggests possible genomic actions.
Detection of estrogen receptor mRNA in trout pineal and retina: estradiol-17 beta modulates melatonin production by cultured pineal photoreceptor cells.
The present results suggest that estradiol-17 beta receptors are expressed in the fish pineal and retina and that est radiol- 17 beta modulates melatonin secretion by cultured pineal photoreceptors.
Evidences associating pineal gland function with alterations in pigmentation
Out from this work have come many acceptable evidences of a pineal gland influence upon pigmentation, upon the phases of colloidal state, and upon the vegetative nervous system.
Melatonin secretion in vitro from the pineal complex of the lamprey Petromyzon marinus.
This is the first direct evidence of melatonin secretion in a lamprey, suggesting that both light and temperature can affect in vitromelatonin secretion.