Effect of photic manipulation on the level of melatonin in the retinas of frogs (Rana tigrina regulosa)

Pang, S.F.; Shiu, Stephen Y. W.; Tse, Shun-ting

doi:10.1016/0016-6480(85)90120-0

Cited by 34 publications

(3 citation statements)

References 21 publications

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“…In guinea pigs, chickens, quails, and frogs, the normal low level of retinal melatonin in the light period increased after dark treatment and the normal high level of retinal melatonin in the dark period was lowered following light exposure ( fig. 2) [30,31,Allen and Pang,unpubl. results].…”

Section: Evidence For the Direct Transduction Of Light To Melatonin Smentioning

confidence: 99%

Sensory Receptors as a Special Class of Hormonal Cells

1991

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Classically, sensory receptors are specialized cells which detect specific environmental disturbances and send out neural signals for the integration, control and/or regulation of effector organs. Recently, a special class of sensory receptors called sensori-hormonal cells which employ hormones as their means of flux of biological information has been proposed. These sensori-hormonal cells are capable of detecting and transducing environmental signals directly into the secretion of hormones within the same cells. Theoretically, all sensory receptors may have examples capable of direct sensori-hormonal transduction. However, only one group of sensori-hormonal cells, the photoendocrine cells, have so far been studied. The photoendocrine cells including the photoreceptors of fish retinas and pinealocytes of bird pineals are capable of detecting light and/or darkness and transducing the electromagnetic radiation energy into a hormonal output. Generally, light suppresses and darkness stimulates the biosynthesis and secretion of melatonin by these photoendocrine cells. Contrary to many hormonal systems which employ principally the feedback mechanism for regulation, the sensori-hormonal cells are predominantly controlled by the feedforward mechanism. However, other factors may serve as additional means of regulation by influencing the system and affecting the transduction processes and/or the synthesis and secretion of the hormone. The ability of sensori-hormonal transduction is suggested to be important for the survival of the organism itself and/or its species and sensori-hormonal cells or their equivalent should appear early in the course of animal evolution. It is further suggested that the sequence of appearance of melatonin functions in the course of evolution would be: hormone – humoral factor – neuromodulator – neurotransmitter.

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Section: Evidence For the Direct Transduction Of Light To Melatonin Smentioning

confidence: 99%

Sensory Receptors as a Special Class of Hormonal Cells

1991

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“…It is secreted from the pineal gland driven by retinal photic stimuli (q.v. early work in the frog [113] neurally projected to the SCN, and synthesis in the gut.…”

Section: Melatoninmentioning

confidence: 99%

Role of Hormones and Neuropeptides in IBS and other Gastrointestinal Disorders: Understanding Variability and Chrononutrition

et al. 2011

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Mind-brain-body-gene framework, including the role of chrononutrition, is probably implicated in the genesis of functional gastrointestinal diseases (FGIDs). Emphasis was placed on psychosocial dysregulation, the bridging of the Cartesian Gap, and chronobiology viz. the way circadian and other rhythmic structures of the brain, e.g. suprachiasmatic nucleus, and gastrointestinal tract interact partially explaining the phrase "we are what and when we eat". Chronobiological concepts of strain and stress in the context of sensory pain and the time-qualified network of gut hormones and neuropeptides are discussed for melatonin, serotonin, ghrelin, leptin, vasoactive intestinal peptide, neuropeptide Y, orexins, and others. The Tsimtsoum evolutionary aspects of diet from Palaeolithic to modern man in the context of increased omega-3/omega-6 fatty acid ratio reduces proinflammatory responses, important in pre-metabolic syndrome and cardiovascular disease, and protects against neuropsychic disorders possibly (FGIDs). Gut micro-organisms either affect the lumen (food substrates) and mucosa, where they reflect immunological, metabolic and physiologic function and importance of these two ecosystems. The interaction between enteric and autonomic systems and associated regulatory effects on proliferative and secretary epithelial dynamics and optimization of permeability for food nutrients and possible modulation of inflammation is an active area of research. In summary, this paper has focussed on the need to understand the multifarious aspects of biological and environmental variability, principally hormones and neuropeptides, in the possible genesis of (FGIDs).

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“…The present study has also demonstrated photic, but not circadian, regulation of melatonin rhythms in two salmonid teleosts. The ques tion arises why in some species melatonin rhythms are regulated both by light and a circa dian clock [23], while in the other species only by light [24], Menaker and Wisner [18] and Janik and Menaker [21] ecological niches to which they and their ances tors have adapted. Is this hypothesis also appli cable to melatonin rhythms in fishes?…”

Section: Ecological N Iches Influence the Circadian Regulation Of M Ementioning

confidence: 99%

Photic and Circadian Regulations of Melatonin Rhythms in Fishes

Iigo

Hara²,

Ohtani-Kaneko³

et al. 1997

Neurosignals

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Photic and circadian regulations of melatonin rhythms in the pineal organ and the retina of several teleosts were studied to investigate the regulatory mechanisms of melatonin rhythms in fishes. In the eyecup preparations of the goldfish, Carassius auratus, both time of day and lighting conditions affected melatonin production, with high melatonin production observed only in the dark-treated group incubated during the ‘subjective’ night. Thus, in the goldfish retina, local photoreceptors and an ocular circadian clock seem to regulate melatonin production, as in the zebrafish retina and in the pineal organ of a number of teleosts, including the goldfish. However, this circadian regulation of melatonin rhythms is not universal among fishes. Although the superfused pineal organ of the masu salmon Oncorhynchus masou secreted melatonin in a rhythmic fashion under light-dark (LD) cycles, the rhythm disappeared under constant darkness (DD), as in the rainbow trout, with a large amount of melatonin released both during the subjective day and the subjective night. These results suggest that all salmonids lack circadian regulation of melatonin rhythms. Furthermore, when ocular melatonin rhythms were compared in two cyprinids, the ugui Tribolodon hakonensis and the oikawa Zacco platypus occupying different ecological niches, ocular melatonin contents exhibited daily variations, with higher values during the dark phase of LD cycles in both species. The rhythmic changes persisted in the ugui under DD, with higher levels at subjective midnight than at subjective midday; however, ocular melatonin levels in the oikawa were consistently high under DD. Thus, the circadian regulation of melatonin rhythms in fishes is influenced not only by phylogeny, but also by the ecological niches of the animals. These results suggest that the physiological functions of melatonin in the circadian and photoperiodic systems differ among fishes.

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Effect of photic manipulation on the level of melatonin in the retinas of frogs (Rana tigrina regulosa)

Cited by 34 publications

References 21 publications

Sensory Receptors as a Special Class of Hormonal Cells

Sensory Receptors as a Special Class of Hormonal Cells

Role of Hormones and Neuropeptides in IBS and other Gastrointestinal Disorders: Understanding Variability and Chrononutrition

Photic and Circadian Regulations of Melatonin Rhythms in Fishes

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