Loss of Serotonin Circadian Rhythms in the Pineal Gland of Androgenized Female Rats

1980 ◽  
Vol 31 (4) ◽  
pp. 265-269 ◽  
Author(s):  
Richard F. Walker ◽  
Paola S. Timiras
Keyword(s):  
Circadian Rhythms ◽  
Pineal Gland ◽  
Female Rats

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.

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.

PEPTIDE REGULATES HUMAN CIRCADIAN RHYTHMS GENES EXPRESSION DURING PINEAL GLAND ACCELERATED AGING

2020 ◽  
pp. 429-435
Author(s):  
О. М. Ивко ◽  
Н. С. Линькова ◽  
А. Р. Ильина ◽  
А. А. Шарова ◽  
Г. А. Рыжак
Keyword(s):  
Circadian Rhythms ◽  
Pineal Gland ◽  
Circadian Clock ◽  
Peripheral Blood ◽  
Accelerated Aging ◽  
Peripheral Blood Lymphocytes ◽  
Circadian Genes ◽  
Blood Lymphocytes ◽  
Aged People ◽  
Genes Expression

Ночная работа приводит к десинхронизации биоритмов, нарушению мелатонинобразующей функции и ускоренному старению эпифиза человека. Одним из перспективных геропротекторов, восстанавливающих синтез эпифизарного мелатонина, является пептид AEDG ( Ala-Glu-Asp-Gly ). Последний в 1,7 раза повышает экскрецию 6-сульфатоксимелатонина в моче людей среднего возраста, у которых этот показатель исходно снижен. Кроме того, у людей со сниженной мелатонинобразующей функцией эпифиза, пептид AEDG нормализует повышенную экспрессию циркадных генов Clock и Csnk 1 e в лейкоцитах и в 2 раза повышает сниженную экспрессию гена Cry 2 в лимфоцитах крови. В основе геропротекторного эффекта пептида AEDG лежит его способность восстанавливать мелатонинобразующую функцию эпифиза через регуляцию экспрессии часовых генов человека. Night work provides biorhythms desynchronization, disorder of melatonin-producing function and accelerated pineal gland aging. One of the promising geroprotectors restoring the pineal melatonin synthesis is the AEDG ( Ala-Glu-Asp-Gly ) peptide. AEDG peptide increases in 1,7 times the 6-sulfatoxymelatonin (6-SOMT) excretion in the urine of middle-aged people. Moreover, AEDG peptide normalized circadian Clock and Csnk1e genes hyper expression in leukocytes in 1,9-2,1 times and increases the Cry 2 gene hypo expression in peripheral blood lymphocytes in 2 times in people with reduced melatonin-producing epiphysis function. The geroprotective effect of the AEDG peptide is based on its ability to restore the epiphysis melatonin-producing function by means regulation of human circadian genes expression.

scholarly journals Role and Therapeutic Potential of Melatonin in the Central Nervous System and Cancers

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1567
Author(s):  
Sangiliyandi Gurunathan ◽  
Min-Hee Kang ◽  
Jin-Hoi Kim
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Circadian Rhythms ◽  
Pineal Gland ◽  
Therapeutic Potential ◽  
Neurological Diseases ◽  
Dark Phase ◽  
Anti Inflammatory ◽  
The Impact

Melatonin (MLT) is a powerful chronobiotic hormone that controls a multitude of circadian rhythms at several levels and, in recent times, has garnered considerable attention both from academia and industry. In several studies, MLT has been discussed as a potent neuroprotectant, anti-apoptotic, anti-inflammatory, and antioxidative agent with no serious undesired side effects. These characteristics raise hopes that it could be used in humans for central nervous system (CNS)-related disorders. MLT is mainly secreted in the mammalian pineal gland during the dark phase, and it is associated with circadian rhythms. However, the production of MLT is not only restricted to the pineal gland; it also occurs in the retina, Harderian glands, gut, ovary, testes, bone marrow, and lens. Although most studies are limited to investigating the role of MLT in the CNS and related disorders, we explored a considerable amount of the existing literature. The objectives of this comprehensive review were to evaluate the impact of MLT on the CNS from the published literature, specifically to address the biological functions and potential mechanism of action of MLT in the CNS. We document the effectiveness of MLT in various animal models of brain injury and its curative effects in humans. Furthermore, this review discusses the synthesis, biology, function, and role of MLT in brain damage, and as a neuroprotective, antioxidative, anti-inflammatory, and anticancer agent through a collection of experimental evidence. Finally, it focuses on the effect of MLT on several neurological diseases, particularly CNS-related injuries.

scholarly journals Increase in 6-Hydroxymelatonin Excretion in Humans during Ascent to High Altitudes

2004 ◽  
Vol 89 (9) ◽  
pp. 4388-4390 ◽  
Author(s):  
Herwig Frisch ◽  
Franz Waldhauser ◽  
Thomas Waldhör ◽  
Andrea Müllner-Eidenböck ◽  
Pritam Neupane ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Circadian Rhythms ◽  
Pineal Gland ◽  
Diurnal Variation ◽  
Healthy Volunteers ◽  
High Altitude ◽  
Physiological Role ◽  
Physiological Significance ◽  
High Altitudes ◽  
Lower Altitude

Melatonin (MLT), the pineal gland hormone involved in the regulation of circadian rhythms, shows characteristic diurnal variation. Its physiological role in humans is not clear. Exposure to high altitudes may disrupt the circadian rhythm and lead to various endocrine changes. MLT in humans has not been studied under these conditions. Urinary 6-hydroxy-MLT sulfate (aMT6s) excretion was analyzed during the day (0700–2200 h) and night (2200–0700 h) phases. A cohort of 33 healthy volunteers, aged 19–65 yr, was studied during an ascent to a high altitude in the Himalayas on three occasions (at a lower altitude, at 3400 m, and after reaching maximal altitudes of 5600–6100 m). aMT6s excretion during the daytime remained unchanged during exposure to high altitudes. As expected, nocturnal values were higher than diurnal values at each point in time. However, there was a significant increase in nocturnal MLT excretion after the ascent to high altitudes. Ascent to high altitudes is associated with increased nocturnal excretion of aMT6s. The mechanism and physiological significance of this MLT increase are unclear.

scholarly journals Pineal Proteins Upregulate Specific Antioxidant Defense Systems in the Brain

2009 ◽  
Vol 2 (2) ◽  
pp. 88-92 ◽  
Author(s):  
Vijay K. Bharti ◽  
R. S. Srivastava
Keyword(s):  
Oxidative Stress ◽  
Pineal Gland ◽  
Antioxidant Defense ◽  
Bubalus Bubalis ◽  
Female Rats ◽  
Antioxidant Systems ◽  
Secretory Product ◽  
Defense Systems ◽  
Antioxidant Defense Systems ◽  
The Brain

The neuroendocrine functions of the pineal affect a wide variety of glandular and nervous system processes. Beside melatonin (MEL), the pineal gland secretes and expresses certain proteins essential for various physiological functions. It has been suggested that the pineal gland may also have an antioxidant role due to secretory product other than MEL. Therefore, the present study was designed to study the effect of buffalo (Bubalus bubalis) pineal proteins (PP) on the antioxidant defense system in the brain of female rats. The twenty-four rats were taken in present study and were divided into four groups: control (0 day), control (28 day), vehicle control and buffalo PP. The PP was injected 100 µg/kg BW intraperitoneal (i.p.) daily for 28 days. The activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione reductase (GR) and reduced glutathione (GSH) concentration and the levels of lipid peroxidation (LPO) in the brain tissue were measured to assess the antioxidant systems. These enzymes protect from adverse effects of free radicals and help in amelioration of oxidative stress. Buffalo pineal proteins administration did not cause any effect on brain LPO, whereas GPx, GR and GSH were significantly (p < 0.05) decreased. However, SOD and CAT activities were increased to significant levels than the control in PP treated rats. Our study herein suggested that buffalo (Bubalus bubalis) pineal proteins upregulates specific antioxidant defense systems and can be useful in control of various oxidative stress-induced neuronal diseases.

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