Ultrastructural detection of the vasopressin messenger RNA in the normal and Brattleboro rat.

The messenger RNA coding for vasopressin has been detected at the ultrastructural level in normal and Brattleboro rat neurons, by using an oligonucleotide rat AVP prove labelled with 35SdATP. Vibratome sections of rat hypothalamus fixed with a mixture of 4% formaldehyde and 0.1% glutaraldehyde were hybridized with the probe, osmicated, included in Araldite and cut in semi-thin and thin sections that were coated with emulsion. The results demonstrate that vasopressin mRNA can be visualized in the cytoplasm of normal and Brattleboro rat neurons with an acceptable preservation of the ultrastructural aspect of the tissue. In Brattleboro rat neurons, the vasopressin mRNA is preferentially located at the periphery of the cytoplasm and is less abundant than in normal rat, this suggesting that the single base gene deletion observed in the Brattleboro rat provokes an altered transcription and compartmentation of the corresponding mRNA.