RGD Reference Report - Stimulatory effects of LH on release of melatonin and activities of its synthesizing enzymes NAT and HIOMT in organ-cultured pineal glands of female rats. - Rat Genome Database

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Stimulatory effects of LH on release of melatonin and activities of its synthesizing enzymes NAT and HIOMT in organ-cultured pineal glands of female rats.

Authors: Hosaka, T  Mimuro, T  Hamada, N  Itoh, MT  Ishizuka, B 
Citation: Hosaka T, etal., Horm Metab Res 2002 Aug;34(8):441-5.
RGD ID: 1359073
Pubmed: PMID:12198599   (View Abstract at PubMed)
DOI: DOI:10.1055/s-2002-33602   (Journal Full-text)

The pineal hormone melatonin (N-acetyl-5-methoxytryptamine) exerts antigonadotropic effects in some mammalian species. To evaluate the effect of luteinizing hormone (LH) on melatonin release and its synthesizing enzyme activities in pineal glands, pineals of adult female rats undergoing diestrus were organ-cultured in a medium containing 10(-12), 10(-10) or 10(-8) M LH for 6 h. Melatonin release increased significantly in pineals cultured with 10(-12) and 10(-10) M LH, as compared to control values. Similarly, the activity of arylalkylamine N-acetyltransferase (NAT), the key regulatory enzyme in melatonin biosynthesis, was significantly higher in pineals cultured with 10(-12) and 10(-10) M LH for 6 h, while LH at 10(-8) M had no effect. Although LH at 10(-10) M increased pineal hydroxyindole-O-methyltransferase (HIOMT) activity, which catalyzes the final step of melatonin biosynthesis, LH at 10(-12) and 10(-8) M had no effect. These results demonstrate that at relatively low physiological levels, LH stimulates pineal melatonin synthesis and release, mainly by increasing NAT activity.



Gene Ontology Annotations    Click to see Annotation Detail View

Biological Process

  
Object SymbolSpeciesTermQualifierEvidenceWithNotesSourceOriginal Reference(s)
AsmtRatmelatonin biosynthetic process  IDA  RGD 

Molecular Function

  
Object SymbolSpeciesTermQualifierEvidenceWithNotesSourceOriginal Reference(s)
AsmtRatacetylserotonin O-methyltransferase activity  IDA  RGD 
AsmtRatS-adenosylmethionine-dependent methyltransferase activity  IDA  RGD 

Molecular Pathway Annotations    Click to see Annotation Detail View

RGD Manual Annotations


  
Object SymbolSpeciesTermQualifierEvidenceWithNotesSourceOriginal Reference(s)
AsmtRathomocysteine metabolic pathway   NAS  RGD 
AsmtRatmethionine cycle/metabolic pathway   IDA  RGD 
Objects Annotated

Genes (Rattus norvegicus)
Asmt  (acetylserotonin O-methyltransferase)


Additional Information