ISSN:
1432-0878
Keywords:
Key words Hydroxyindole-O-methyltransferase
;
Pineal gland
;
In situ hybridisation
;
Melatonin
;
5-Methoxyindoles
;
Rat (Wistar)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Hydroxyindole-O-methyltransferase (HIOMT) is the enzyme involved in the last step of the melatonin synthesis pathway. Recently, a cDNA encoding HIOMT has been isolated from a rat pineal gland library. Using this cDNA, we developed a highly sensitive in situ hybridisation protocol to investigate the distribution of HIOMT mRNA in both the rat brain and dissociated pinealocytes maintained in primary cell culture. In the rat brain, HIOMT mRNA was only detected in the three parts of the pineal complex: the superficial pineal, the stalk and the deep pineal. No extra-pineal hybridisation labelling was observed. These results strongly suggest that melatonin synthesis also occurs in the deep part and the stalk of the pineal gland. HIOMT mRNA was markedly expressed in cultured pinealocytes. No particular subcellular area was observed to express HIOMT mRNA specifically, as the labelling was homogeneously distributed in the cytosol and in the axon-like processes. In conclusion, the use of in situ and in vitro hybridisation with a pineal riboprobe has detected notable HIOMT expression restricted to pinealocytes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004410051011
Permalink
