Effects of retinal and pineal low molecular weight fractions and antipsychotic drugs on hydroxyindole-O-methyltransferase

Cremer-Bartels, G.; Ebels, I.; Sykes, Jane E.; Moreé, A. de

doi:10.1007/bf01249129

Cited by 14 publications

(5 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…HIOMT activity in rat pineal gland is reduced by indomethacin administration (28). The neuroleptics, CPZ and HPD, reduce the HIOMT activity in vitro (29). From these findings, CPZ, HPD, DZP and HYZ may also cause a reduction of pineal HIOMT activity in vivo, as similarly reported for CPZ and HPD in vitro.…”

Section: Discussionsupporting

confidence: 67%

Effect of psychotropic drugs on the contents of melatonin, serotonin and N-acetylserotonin in rat pineal gland.

et al. 1989

View full text Add to dashboard Cite

Abstract-In the dark phase, the effects of the psychotropic drugs on the contents of melatonin, serotonin (5-HT) and N-acetylserotonin (NAS) in rat pineal gland were examined. The pineal gland was removed at a certain period of time after subcutaneous injection of the drugs. 5-HT, NAS and melatonin contents in the pineal gland were determined by high performance liquid chromatography with fluorometric detection. A dose-dependent decrease was observed for melatonin content in the administration of diazepam (DZP), hydroxyzine (HYZ), chlorprom azine (CPZ) or haloperidol (HPD). When imipramine (IPM) or amitriptyline (APL) was given to rats, pineal 5-HT content was significantly decreased. On the other hand, the administration of IPM or APL caused increases in pineal NAS and melatonin. Furthermore, the administration of phenytoin (PYT) revealed no changes in the content of pineal indoleamines. These results suggest that the psychotropic drugs widely used in clinical applications could cause significant changes in pineal indoleamine content.

show abstract

Section: Discussionsupporting

confidence: 67%

Effect of psychotropic drugs on the contents of melatonin, serotonin and N-acetylserotonin in rat pineal gland.

et al. 1989

View full text Add to dashboard Cite

show abstract

“…As one of the key enzymes in the biosynthesis of melatonin, the important role of HIOMT is recognized [24] and haloperidol is a recognized inhibitor of HIOMT [11–13]. The concentration of haloperidol used in the present study was equal to the dosage used by clinicians in the treatment of schizophrenia.…”

Section: Discussionmentioning

confidence: 99%

“…Melatonin is mainly synthesized in the pineal gland, and N‐acetyltransferase (NAT) and 5‐hydroxyindole‐O‐methyltransferase (HIOMT) are the two key enzymes for the biosynthesis of melatonin. Haloperidol is an inhibitor of HIOMT [11–13], thereby interrupting the biosynthesis of melatonin. The aim of the present study is to investigate the in vivo effect of inhibiting melatonin biosynthesis on spatial memory retention of rats and tau phosphorylation, and the possible underlying mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Effect of inhibiting melatonin biosynthesis on spatial memory retention and tau phosphorylation in rat

Zhu

Wang

Ling

et al. 2004

Journal of Pineal Research

View full text Add to dashboard Cite

We have found recently that melatonin protects SH-SY5Y neuroblastoma cells from calyculin A-induced neurofilament impairment and neurotoxicity. In the present study, we further investigated the in vivo effect of inhibiting melatonin biosynthesis on spatial memory retention and tau phosphorylation in rats and the potential underlying mechanisms by using haloperidol, a specific inhibitor of 5-hydroxyindole-O-methyltransferase, and a key enzyme in melatonin biosynthesis. We have found that injection of haloperidol into the lateral ventricle and into peritoneal cavity compromises spatial memory retention of rats and induces hyperphosphorylation of microtubule-associated protein tau at tau-1 (Ser199/Ser202) and PHF-1 (Ser396/Ser404) epitopes. At mean time, the activity of protein phosphatase-2A (PP-2A), a deficit phosphatase in the Alzheimer's disease brain and superoxide dismutase decreases with an elevated level of malondialdehyde. Supplementation with melatonin by prior injection for 1 wk and reinforcement during the haloperidol administration significantly improves memory retention deficits, arrests tau hyperphosphorylation and oxidative stress, and restores PP-2A activity. These results strongly support the involvement of decreased melatonin in Alzheimer-like spatial memory impairment and tau hyperphosphorylation, and PP-2A may play a role in mediating aberrant melatonin-induced lesions.

show abstract

“…Indeed, since depression is a major risk factor associated with the development of T D and drug-induced Parkinsonism (Kane et al, 1988), reduced melatonin functions may facilitate the development of these movement disorders in susceptible individuals. Moreover, since neuroleptics have been reported to accumulate preferentially in the pineal gland in rats (Naylor & Olley, 1969) and inhibit pineal and retinal melatonin synthesis by blocking the activity of hydroxyindole-0-methyltransferase (HTOMT) (the final enzyme in melatonin biosynthesis) (Cremer- Bartels et al, 1983;Hartley et al, 1972). it is possible that the mechanisms by which neuroleptics induce extrapyramidal motor side-effects may be mediated not only through blockade of striatal DA receptors, but also in part through inhibition of pineal melatonin secretion.…”

mentioning

confidence: 99%

Pineal Melatonin Functions: Possible Relevance to Parkinson's Disease

Sandyk

1990

International Journal of Neuroscience

View full text Add to dashboard Cite

Barbeau hypothesized that Parkinson's disease is associated with hypothalamic deficiency of the specialized neuroendocrine cell system (A.P.U.D.) and that the degeneration of brainstem monoaminergic neurons is secondary to progressive functional loss of this cell system in the disease. The pineal gland meets criteria of the A.P.U.D. cell system and it is possible that dysfunction of the pineal gland may be associated with the pathophysiology and clinical manifestations of Parkinson's disease. Since the role of pineal melatonin in humans remains enigamatic, it is currently unclear which of the symptoms of Parkinson's disease may be associated with deregulation of the secretory activity of pineal melatonin. This review summarizes evidence linking possible alterations of pineal melatonin functions with the clinical manifestations of Parkinson's disease.

show abstract

Effects of retinal and pineal low molecular weight fractions and antipsychotic drugs on hydroxyindole-O-methyltransferase

Cited by 14 publications

References 11 publications

Effect of psychotropic drugs on the contents of melatonin, serotonin and N-acetylserotonin in rat pineal gland.

Effect of psychotropic drugs on the contents of melatonin, serotonin and N-acetylserotonin in rat pineal gland.

Effect of inhibiting melatonin biosynthesis on spatial memory retention and tau phosphorylation in rat

Pineal Melatonin Functions: Possible Relevance to Parkinson's Disease

Contact Info

Product

Resources

About