Development and melatonin content of the deep pineal gland in the syrian hamster

Sheridan, Michael N.; Rollag, Mark D.

doi:10.1002/aja.1001680204

Cited by 18 publications

(11 citation statements)

References 16 publications

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“…In the preliminary study we found that the nocturnal elevation of pineal and circulating melatonin in the strain of hamsters used by us occurred at about 0200 h. This agreed with a couple of published reports [Sheridan and Rollag, 1983; Rollag and Stetson, 19811. Tamarkin et al [ 19801 selected the nocturnal peak time point of 2200 h for pineal melatonin, basing their expectation on previous work with adult hamsters [Wilkinson et al, 1977;Tamarkin et al, 19791. However, in our species the 2300 h level was found to be lower than the 0200 h level.…”

Section: Discussionsupporting

confidence: 89%

“…The current report on the ontogenesis of the synthesis of various pineal compounds in Syrian hamster and their release in the circulating system agrees as well as disagrees with the few reports so far published on this topic. In the preliminary study we found that the nocturnal elevation of pineal and circulating melatonin in the strain of hamsters used by us occurred at about 0200 h. This agreed with a couple of published reports [Sheridan and Rollag, 1983; Rollag and Stetson, 19811 Tamarkin et al, 19791. However, in our species the 2300 h level was found to be lower than the 0200 h level. Although pineal melatonin was detectable in the animals at 5 days of postnatal age, significant day-night differences occurred only at 25 days of age.…”

Section: Discussionmentioning

confidence: 99%

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Rhythm Development in Pineal and Circulating Serotonin, N‐Acetylserotonin, and Melatonin in Syrian Hamsters

Sato

Attanasio²,

Wake³

et al. 1989

Journal of Pineal Research

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The ontogeny of diurnal rhythm patterns in the pineal and serum levels of melatonin, serotonin, and N-acetylserotonin was studied in Syrian hamsters (Mesocricetus auratus) from birth to adulthood. The pineal and blood specimens were collected at 1100 h and 0200 h, and the compounds were measured by radioimmunoassay (RIA) procedures. Pineal melatonin and serotonin did not show any circadian rhythm at day 5 of postnatal age. At this age N-acetylserotonin was undetectable in the light phase but became manifest at night. By 10 days of age pineal serotonin registered an established rhythm pattern, with a higher level during the day. The occurrence of circadian rhythm in pineal melatonin was delayed and manifested first at 25 days of age. At this age, the first detectable daytime level of N-acetylserotonin also occurred. Circadian rhythm in serum melatonin was also established at this age. The serum serotonin did not evince any rhythm pattern throughout the observation period, except at day 17 of postnatal age. The massive concentration of daytime serotonin in the pineal was not reflected in the circulatory system. For serum N-acetylserotonin there was no discernable day-night rhythm in all age groups, except at 25 days of age. The results show that the timing of the appearance of various compounds in the neonatal pineal is variable; the release of the substances does not always reflect their synthesis; the ontogenesis of circadian rhythm is a part of the maturational process; and 25 days of age is a rather critical time in development.

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Section: Discussionsupporting

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Rhythm Development in Pineal and Circulating Serotonin, N‐Acetylserotonin, and Melatonin in Syrian Hamsters

Sato

Attanasio²,

Wake³

et al. 1989

Journal of Pineal Research

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“…At P30, a significant day/night rhythm in AA‐NAT activity is observed, which is consistent with published values (18). The elaboration of the daily rhythm in pineal activity could depend on the sympathetic fibres invasion in the pineal, which starts at the end of the first week of life (31) and is complete at approximately P15 in Syrian hamsters (32). However, this correlation is questionable since Tamarkin et al .…”

Section: Discussionmentioning

confidence: 99%

Syrian Hamster and Rat Display Developmental Differences in the Regulation of Pineal Arylalkylamine N‐Acetyltransferase

Garidou¹,

Ribelayga²,

Pévet³

et al. 2002

J Neuroendocrinology

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In the Syrian hamster, the role of noradrenaline in the regulation of melatonin synthesis is less clear than in the rat. During pineal ontogenesis in the rat, noradrenaline is the major transmitter involved in the onset of melatonin synthesis and melatonin rhythm. We analysed the involvement of noradrenaline in the ontogenesis of melatonin synthesis in the Syrian hamster and compared it with that of the rat. We followed the developmental profile of melatonin content in parallel with those of mRNA expression and activity of AA-NAT, the melatonin rhythm-generating enzyme. In addition, we tested the effect of noradrenergic drugs at early steps of pineal ontogenesis. In the Syrian hamster, the night-time Aa-nat mRNA, first detected 3 days after birth, increases progressively up to a maximum reached at 30 days of age and then decreases significantly towards adulthood. The daytime level of Aa-nat mRNA remains always low. A significant day/night rhythm appears 10 days after birth, is maximal (200-fold nocturnal increase) 30 days after birth and decreases slowly towards adulthood. Ontogenesis of the AA-NAT activity rhythm is similar, although with a much lower amplitude of day/night variations (four-fold). The developmental pattern of melatonin content is similar to that of AA-NAT and could be correlated with the appearance of sympathetic innervation in the pineal gland. However, neither alpha- nor beta-adrenergic antagonists inhibit the night-time Aa-nat mRNA transcription in the 9-day-old Syrian hamster, in contrast to what is observed in the adult. For comparison, the beta-adrenergic antagonist propranolol inhibits Aa-nat gene expression in 2-day-old rat. These results show that both species are different in the regulation of the appearance of melatonin synthesis and that Syrian hamster is peculiar from birth in term of noradrenaline involvement in the activation of melatonin synthesis.

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“…The pineals were quickly dissected, frozen in liquid nitrogen and stored at --80 ~ until determination. Because in the deep pineal neither HIOMT activity nor aMT content could be detected (P6vet et al, 1980;Sheridan and Rollag, 1983), only the superficial pineal gland was dissected. After dissection of the pineal gland, both testes were removed and weighed immediately.…”

Section: Methodsmentioning

confidence: 99%

The influence of light of different wavelengths on the methylating capacity of the pineal gland of male golden hamsters in relation to reproduction

Benthem

Steinen

Sommer

et al. 1989

J. Neural Transmission

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In the present experiments the influence of light of different wavelengths on pineal indole metabolism in relation to reproduction was studied. Therefore, during autumn and winter male golden hamsters were kept under natural conditions but for the sunlight which was filtered exposing the hamsters to either normal (control), red or blue light. During the gradually shortening photoperiod at the start of the experiments under normal light conditions, a marked decrease of FSH and LH plasma content as well as testicular weight was found, indicating the onset of gonadal atrophy. During this period a high synthesis of 5-methoxytryptophan (MW) and 5-methoxytryptamine (MT) was determined. The synthesis of other 5-methoxyindoles (MI) was low, while O-acetyl-5-methoxytryptophol (aML) synthesis even markedly decreased. Red and blue light did not cause significant changes in MI synthesis. As long as MT synthesis is high (under blue light), there is no increase in FSH content and testes weight is still decreasing. This influence of blue light confirms the putative antigonadotropic properties of MT. The increase of FSH content at week 9 was the first indication that recrudescence had started. At week 19, this recrudescence was also manifested in the increasing testes weight. The synthesis of melatonin (aMT), 5-methoxytryptophol (ML), 5-methoxyindole-3-acetic acid (MA) and aML increased whereas the production of MT decreased. Blue light exposure caused a significantly higher increase of synthesis of ML, MA, aML and, not-significantly, of aMT, whereas red light caused a significantly lower synthesis of MA. It was concluded that MT, a putative antigonadotropic, and aML, a putative counter-antigonadotropic, are probably important pineal compounds that transduce the photoperiodic messages, which cause either gonadal atrophy or recrudescence. The effect of blue light on indole metabolism and the reproductive cycle was more clear than that of red light. From the present results of blue light on indole metabolism, it was suggested that blue light delayed gonadal atrophy and stimulated gonadal growth, compared to red light. An opposite effect of red light was less obvious.

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Development and melatonin content of the deep pineal gland in the syrian hamster

Cited by 18 publications

References 16 publications

Rhythm Development in Pineal and Circulating Serotonin, N‐Acetylserotonin, and Melatonin in Syrian Hamsters

Rhythm Development in Pineal and Circulating Serotonin, N‐Acetylserotonin, and Melatonin in Syrian Hamsters

Syrian Hamster and Rat Display Developmental Differences in the Regulation of Pineal Arylalkylamine N‐Acetyltransferase

The influence of light of different wavelengths on the methylating capacity of the pineal gland of male golden hamsters in relation to reproduction

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