Effect of cocaine on rat pineal melatonin synthesis in vivo and in vitro

1990 ◽  
Vol 34 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Gregory F. Oxenkrug ◽  
Ljubisa J. Dragovic ◽  
Bernard H. Marks ◽  
Arthur Yuwiler
Keyword(s):  
Pineal Melatonin ◽  
Melatonin Synthesis

Melatonin synthesis enzymes interact with ascorbate peroxidase to protect against oxidative stress in cassava

2020 ◽  
Vol 71 (18) ◽  
pp. 5645-5655 ◽  
Author(s):  
Yujing Bai ◽  
Jingru Guo ◽  
Russel J Reiter ◽  
Yunxie Wei ◽  
Haitao Shi
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Capacity ◽  
Stress Tolerance ◽  
Ascorbate Peroxidase ◽  
Stress Responses ◽  
Direct Interaction ◽  
Ros Scavenging ◽  
Melatonin Synthesis

Abstract Melatonin is an important indole amine hormone in animals and plants. The enzymes that catalyse melatonin synthesis positively regulate plant stress responses through modulation of the accumulation of reactive oxygen species (ROS). However, the relationship between melatonin biosynthetic enzymes and ROS-scavenging enzymes has not been characterized. In this study, we demonstrate that two enzymes of the melatonin synthesis pathway in Manihot esculenta (MeTDC2 and MeASMT2) directly interact with ascorbate peroxidase (MeAPX2) in both in vitro and in vivo experiments. Notably, in the presence of MeTDC2 and MeASMT2, MeAPX2 showed significantly higher activity and antioxidant capacity than the purified MeAPX2 protein alone. These findings indicate that MeTDC2–MeAPX2 and MeASMT2–MeAPX2 interactions both activate APX activity and increase antioxidant capacity. In addition, the combination of MeTDC2, MeASMT2, and MeAPX2 conferred improved resistance to hydrogen peroxide in Escherichia coli. Moreover, this combination also positively regulates oxidative stress tolerance in cassava. Taken together, these findings not only reveal a direct interaction between MeTDC2, MeASMT2, and MeAPX2, but also highlight the importance of this interaction in regulating redox homoeostasis and stress tolerance in cassava.

Evidence that extremely low frequency Ca2+-cyclotron resonance depresses pineal melatonin synthesis in vitro

1991 ◽  
Vol 124 (2) ◽  
pp. 213-215 ◽  
Author(s):  
Alexander Lerchl ◽  
Russel J. Reiter ◽  
Kimberly A. Howes ◽  
Keico O. Nonaka ◽  
Karl-Arne Stokkan
Keyword(s):  
Cyclotron Resonance ◽  
Low Frequency ◽  
Extremely Low Frequency ◽  
Pineal Melatonin ◽  
Melatonin Synthesis

scholarly journals Leptin Modulates Norepinephrine-Mediated Melatonin Synthesis in Cultured Rat Pineal Gland

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Rodrigo Antonio Peliciari-Garcia ◽  
Jéssica Andrade-Silva ◽  
José Cipolla-Neto ◽  
Carla Roberta de Oliveira Carvalho
Keyword(s):  
Pineal Gland ◽  
Leptin Receptor ◽  
Pineal Melatonin ◽  
Melatonin Synthesis ◽  
Inducible Camp Early Repressor ◽  
Per Se ◽  
Isoform B ◽  
Rat Pineal Gland

Pineal melatonin synthesis can be modulated by many peptides, including insulin. Because melatonin appears to alter leptin synthesis, in this work we aimed to investigate whether leptin would have a role on norepinephrine- (NE-)mediated melatonin synthesis in cultured rat pineal glands. According to our data, cultured rat pineal glands express leptin receptor isoform b (Ob-Rb). Pineal expression ofOb-RbmRNA was also observedin vivo. Administration of leptin (1 nM) associated with NE (1 µM) reduced melatonin content as well as arylalkylamine-N-acetyl transferase (AANAT) activity and expression in cultured pineal glands. Leptin treatment per se induced the expression of STAT3 in cultured pineal glands, but STAT3 does not participate in the leptin modulation of NE-mediated pineal melatonin synthesis. In addition, the expression of inducible cAMP early repressor (ICER) was further induced by leptin challenge when associated with NE. In conclusion, leptin inhibition of pineal melatonin synthesis appears to be mediated by a reduction in AANAT activity and expression as well as by increased expression ofIcermRNA. Peptidergic signaling within the pineal gland appears to be one of the most important signals which modulates melatonin synthesis; leptin, as a member of this system, is not an exception.

In vivo and in vitro effects of X-irradiation and histamine-PO4 on rat and bovine pineal hiomt activity and melatonin synthesis

Life Sciences ◽  
1973 ◽  
Vol 13 (7) ◽  
pp. 835-845 ◽  
Author(s):  
LeGrande C. Ellis ◽  
August W. Jaussi ◽  
G. Robert Tait ◽  
Ronald L. Urry
Keyword(s):  
Melatonin Synthesis ◽  
X Irradiation ◽  
In Vitro Effects

scholarly journals The muscarinic effect of anhydroecgonine methyl ester, a crack cocaine pyrolysis product, impairs melatonin synthesis in the rat pineal gland

2017 ◽  
Vol 6 (4) ◽  
pp. 420-431 ◽  
Author(s):  
Lívia Silva Medeiros de Mesquita ◽  
Raphael Caio Tamborelli Garcia ◽  
Fernanda Gaspar Amaral ◽  
Rafael Peres ◽  
Simone Miller Wood ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Pineal Gland ◽  
Muscarinic Receptors ◽  
Crack Cocaine ◽  
Pyrolysis Product ◽  
Melatonin Synthesis ◽  
Rat Pineal Gland ◽  
Anhydroecgonine Methyl Ester

AEME impaired melatonin synthesis bothin vivoand in vitro and this effect seems to be mediated by muscarinic receptors and [Ca2+]i elevation.

scholarly journals Daily Rhythm in Pineal Phosphodiesterase (PDE) Activity Reflects Adrenergic/3′,5′-Cyclic Adenosine 5′-Monophosphate Induction of the PDE4B2 Variant

Endocrinology ◽  
2007 ◽  
Vol 148 (4) ◽  
pp. 1475-1485 ◽  
Author(s):  
Jong-So Kim ◽  
Michael J. Bailey ◽  
Anthony K. Ho ◽  
Morten Møller ◽  
Pascaline Gaildrat ◽  
...  
Keyword(s):  
Pineal Gland ◽  
Late Phase ◽  
Daily Rhythm ◽  
Camp Signaling ◽  
Adrenergic Stimulation ◽  
Melatonin Synthesis ◽  
Dependent Protein ◽  
Nocturnal Increase

The pineal gland is a photoneuroendocrine transducer that influences circadian and circannual dynamics of many physiological functions via the daily rhythm in melatonin production and release. Melatonin synthesis is stimulated at night by a photoneural system through which pineal adenylate cyclase is adrenergically activated, resulting in an elevation of cAMP. cAMP enhances melatonin synthesis through actions on several elements of the biosynthetic pathway. cAMP degradation also appears to increase at night due to an increase in phosphodiesterase (PDE) activity, which peaks in the middle of the night. Here, it was found that this nocturnal increase in PDE activity results from an increase in the abundance of PDE4B2 mRNA (∼5-fold; doubling time, ∼2 h). The resulting level is notably higher (>6-fold) than in all other tissues examined, none of which exhibit a robust daily rhythm. The increase in PDE4B2 mRNA is followed by increases in PDE4B2 protein and PDE4 enzyme activity. Results from in vivo and in vitro studies indicate that these changes are due to activation of adrenergic receptors and a cAMP-dependent protein kinase A mechanism. Inhibition of PDE4 activity during the late phase of adrenergic stimulation enhances cAMP and melatonin levels. The evidence that PDE4B2 plays a negative feedback role in adrenergic/cAMP signaling in the pineal gland provides the first proof that cAMP control of PDE4B2 is a physiologically relevant control mechanism in cAMP signaling.

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

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