Development of Daily Cycles in the Pineal Gland

2015 ◽  
pp. 124-131
Author(s):  
S. Binkley ◽  
M. Brammer
Keyword(s):  
Pineal Gland ◽  
Daily Cycles

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.

Low melatonin as a contributor to SARS-CoV-2 disease

2020 ◽  
Vol 3 (4) ◽  
pp. 558-576
Author(s):  
Seithikurippu R Pandi-Perumal ◽  
Daniel P Cardinali ◽  
Russel J Reiter ◽  
Gregory M Brown
Keyword(s):  
Reactive Oxygen Species ◽  
Oxidative Phosphorylation ◽  
Pineal Gland ◽  
Oxygen Species ◽  
Cytokine Storm ◽  
Major Site ◽  
Immune Modulator ◽  
Inflammatory Agent ◽  
Site Of Action ◽  
Extrapineal Melatonin

That the pineal gland is a source of melatonin is widely known; however, by comparison, few know of the much larger pool of extrapineal melatonin. That pool is widely distributed in all animals, including those that do not have a pineal gland, e.g., insects.  Extrapineal melatonin is not released into the blood but is used locally to function as an antioxidant, anti-inflammatory agent, etc. A major site of action of peripherally-produced melatonin is the mitochondria where it neutralizes reactive oxygen species (ROS) that are generated during oxidative phosphorylation. Its role also includes major actions as an immune modulator reducing overreactions to foreign agents while simultaneously boosting immune processes. During a pandemic such as coronavirus disease 2019 (COVID-19), caused by the virus SARS-CoV-2, melatonin is capable of suppressing the damage inflicted by the cytokine storm. The implications of melatonin in susceptibility and treatment of COVID-19 disease are discussed. 

STUDIES ON A NON-MELATONIN PINEAL ANTI-GONADOTROPHIN

1972 ◽  
Vol 69 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Bryant Benson ◽  
Mary Jane Matthews ◽  
Alvin E. Rodin
Keyword(s):  
Solvent Extraction ◽  
Organic Solvent ◽  
Pineal Gland ◽  
Gel Filtration ◽  
Test System ◽  
Pineal Body ◽  
Physiological Effects ◽  
Organic Solvent Extraction ◽  
Gland Function

ABSTRACT Continuing investigation of pineal gland function indicates that the anti-gonadotrophic activity of this organ cannot be attributed solely to the postulated hormone melatonin, the concentration of which is negligible in the pineal body compared to quantities required to produce unequivocal physiological effects. A non-melatonin antigonadotrophic substance recently isolated from bovine pineal glands was further purified by organic solvent extraction, ultrafiltration and gel filtration. Studies of partial blockage of compensatory ovarian hypertrophy in unilaterally ovariectomized Charles River CD-1 mice indicated that this substance is significantly more potent than melatonin in this test system.

PHYSIOLOGICAL EFFECTS OF THE PINEAL GLAND IN ANDROGEN-STERILIZED FEMALE RATS

1970 ◽  
Vol 63 (4) ◽  
pp. 667-678 ◽  
Author(s):  
Russel J. Reiter
Keyword(s):  
Pineal Gland ◽  
Reproductive Organs ◽  
Female Rats ◽  
Inhibitory Influence ◽  
Light Deprivation ◽  
Vaginal Smears ◽  
Adult Rats ◽  
Androgen Treatment ◽  
Postnatal Treatment ◽  
Cervical Ganglia

ABSTRACT The influence of early androgen treatment, light deprivation (by blinding), pinealectomy and superior cervical ganglionectomy on the reproductive system of female rats was tested. Early postnatal treatment of rats with testosterone propionate caused adult rats to exhibit the characteristic signs of androgen sterilization; these included polyfollicular ovaries, normal-sized uteri and persistent vaginal cornification. If early androgentreated rats also were blinded the ovaries were smaller in size and contained fewer follicles, the uteri were greatly reduced in size and the incidence of vaginal oestrus was decreased by approximately 50% If in addition to blinding, androgen-sterilized animals were subjected to either removal of the pineal gland or superior cervical ganglia, the reproductive organs and the vaginal smears were indistinguishable from those of testosterone-treated rats with eyes. These data indicate that the inhibitory influence of blinding on the pituitary-ovarian axis was mediated through the sympathetic nervous system and the pineal gland. The restraining influence of light deprivation on the growth of the reproductive organs was not permanent as illustrated by the fact that if these animals were kept to 120 days of age the ovaries and uteri grew to the same level as those of pinealectomized control rats.

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