scholarly journals Pineal Calcification, Melatonin Production, Aging, Associated Health Consequences and Rejuvenation of the Pineal Gland

Molecules ◽  
2018 ◽  
Vol 23 (2) ◽  
pp. 301 ◽  
Author(s):  
Dun Tan ◽  
Bing Xu ◽  
Xinjia Zhou ◽  
Russel Reiter
Keyword(s):  
Pineal Gland ◽  
Health Consequences ◽  
Melatonin Production

Monosodium glutamate administration early in life alters pineal melatonin nocturnal profile in adulthood

2021 ◽  
Vol 4 (1) ◽  
pp. 99-114
Author(s):  
Janaína B Garcia ◽  
Fernanda G Do Amaral ◽  
Daniela C Buonfiglio ◽  
Rafaela FA Vendrame ◽  
Patrícia L Alves ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Body Weight ◽  
Pineal Gland ◽  
Serum Insulin ◽  
Monosodium Glutamate ◽  
Female Rats ◽  
Pineal Melatonin ◽  
Melatonin Synthesis ◽  
Male And Female Rats ◽  
Melatonin Production

The pineal gland synthesizes melatonin exclusively at night, which gives melatonin the characteristic of a temporal synchronizer of the physiological systems. Melatonin is a regulator of insulin activities centrally and also peripherally and its synthesis is reduced in diabetes.  Since monosodium glutamate (MSG) is often used to induce the type 2 diabetic and metabolic syndrome in animal models, the purpose of this work is to evaluate the potential effects of MSG given to neonates on the pineal melatonin synthesis in different aged male and female rats. Wistar rats were subcutaneously injected with MSG (4mg/g/day) or saline solution (0.9%) from the second to eighth post-natal day. The circadian profiles both melatonin levels and AANAT activity were monitored at different ages. Body weight, naso-anal length, adipose tissues weight, GTT, ITT and serum insulin levels were also evaluated. Typical obesity with the neonatal MSG treatment was observed, indicated by a great increase in adipose depots without a concurrent increase in body weight. MSG treatment did not cause hyperglycemia or glucose intolerance, but induced insulin resistance. An increase of melatonin synthesis at ZT 15 with phase advance was observed in in some animals. The AANAT activity was positively parallel to the melatonin circadian profile. It seems that MSG causes hypothalamic obesity which may increase AANAT activity and melatonin production in pineal gland. These effects were not temporally correlated with insulin resistance and hyperinsulinemia indicating the hypothalamic lesions, particularly in arcuate nucleus induced by MSG in early age, as the principal cause of the increase in melatonin production.

Light-dependent activation of G proteins by two isoforms of chicken melanopsins

2015 ◽  
Vol 14 (11) ◽  
pp. 1991-1997 ◽  
Author(s):  
Masaki Torii ◽  
Daisuke Kojima ◽  
Akiyuki Nishimura ◽  
Hiroshi Itoh ◽  
Yoshitaka Fukada
Keyword(s):  
Comparative Study ◽  
Pineal Gland ◽  
G Protein ◽  
G Proteins ◽  
Melatonin Production

A comparative study of non-visual opsins expressed in the chicken pineal gland showed that melanopsins and pinopsins photoactivate mutually different G protein pathways, which regulate melatonin production.

scholarly journals Melatonin: an endogenous negative modulator of 12-lipoxygenation in the rat pineal gland

1999 ◽  
Vol 344 (2) ◽  
pp. 487-493 ◽  
Author(s):  
Hongjian ZHANG ◽  
Mohammed AKBAR ◽  
Hee-Yong KIM
Keyword(s):  
Pineal Gland ◽  
Negative Ion ◽  
Dark Phase ◽  
Exogenous Melatonin ◽  
Protein Levels ◽  
Endogenous Modulator ◽  
12 Lipoxygenase ◽  
Rat Pineal Gland ◽  
Melatonin Production

Major biochemical activities of the pineal gland include melatonin biosynthesis and 12-lipoxygenation. In this paper, we provide evidence in vivo that melatonin regulates 12-lipoxygenation via 12-lipoxygenase (LOX) expression. The relationship between these two biochemical activities was established by monitoring levels of endogenous melatonin and a 12-LOX metabolite, 12-hydroxyeicosatetraenoic acid (12-HETE), in the rat pineal gland both during the light-dark cycle and after isoproterenol injection using GC/MS with negative ion chemical ionization. As pineal melatonin production reflected a typical diurnal variation, 12-HETE levels showed an off-phase diurnal pattern in relation to melatonin levels. Intravenous administration of isoproterenol, which has been shown to elevate melatonin production, decreased the 12-HETE level significantly. The reduction of 12-HETE levels during the dark phase and after isoproterenol injection was accompanied by decreases in 12-LOX mRNA and protein levels. Direct administration of melatonin to rats by intravenous injection decreased pineal 12-LOX protein levels significantly, indicating that melatonin plays a role in down-regulating 12-LOX expression. When pineal glands were incubated with exogenous melatonin in culture, time-dependent reduction of 12-LOX protein levels was observed. The melatonin-induced reduction in 12-LOX protein was abolished in the presence of the melatonin receptor antagonist luzindole, establishing further the role of melatonin in this process. Incubation of pineal homogenates with exogenous melatonin partially inhibited 12-LOX activity. Taken together, an inverse relationship exists in the endogenous production of 12-HETE, 12-LOX mRNA and protein with respect to melatonin production in the rat pineal gland. Melatonin decreased both 12-LOX mRNA and protein levels in addition to 12-LOX enzyme activity, indicating that melatonin is an endogenous modulator of pineal 12-lipoxygenation.

Effect of lithium on the melatonin production in the pineal gland of viscacha

2008 ◽  
Vol 39 (1) ◽  
pp. 43-55
Author(s):  
Lucia B. Fuentes ◽  
Claudia P. Calderón ◽  
Susana B. García Aseff ◽  
Estela M. Muñoz ◽  
Morten M⊘ller ◽  
...  
Keyword(s):  
Pineal Gland ◽  
Melatonin Production

scholarly journals Homeobox Genes and Melatonin Synthesis: Regulatory Roles of the Cone-Rod Homeobox Transcription Factor in the Rodent Pineal Gland

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Kristian Rohde ◽  
Morten Møller ◽  
Martin Fredensborg Rath
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Circadian Rhythm ◽  
Pineal Gland ◽  
Transcriptional Control ◽  
Homeobox Genes ◽  
Control Mechanisms ◽  
Camp Response Element ◽  
Homeobox Transcription Factor ◽  
Melatonin Production

Nocturnal synthesis of melatonin in the pineal gland is controlled by a circadian rhythm in arylalkylamine N-acetyltransferase (AANAT) enzyme activity. In the rodent,Aanatgene expression displays a marked circadian rhythm; release of norepinephrine in the gland at night causes a cAMP-based induction ofAanattranscription. However, additional transcriptional control mechanisms exist. Homeobox genes, which are generally known to encode transcription factors controlling developmental processes, are also expressed in the mature rodent pineal gland. Among these, the cone-rod homeobox (CRX) transcription factor is believed to control pineal-specificAanatexpression. Based on recent advances in our understanding ofCrxin the rodent pineal gland, we here suggest that homeobox genes play a role in adult pineal physiology both by ensuring pineal-specificAanatexpression and by facilitating cAMP response element-based circadian melatonin production.

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