ESTIMATION OF OXYTOCIN MESSENGER-RNA IN THE HUMAN PARAVENTRICULAR NUCLEUS IN AIDS BY MEANS OF QUANTITATIVE IN-SITU HYBRIDIZATION

Recently, a 40% reduction in the total number of oxytocin immunoreacti ve neurons of the paraventricular nucleus of the hypothalamus in AIDS patients was reported. In the present study, we determined whether thi s decrease is associated with a diminished amount of oxytocin mRNA. We used in situ hybridization combined with densitometric image analysis for the quantitative assessment of oxytocin gene expression in the pa raventricular nucleus of a group of AIDS patients (n = 10) and a caref ully matched control group (n = 8). We found no significant difference (P = 0.08) in the amount of oxytocin mRNA per total paraventricular n ucleus between the two groups. In addition, no significant differences were found in the part of the volume of the paraventricular nucleus t hat was occupied by hybridized cells (P = 0.12) or in the mean signal density (P = 0.08). The findings do not support the hypothesis that th e extensive decrease in oxytocin immunoreactive neurons of the paraven tricular nucleus in AIDS is associated with a decrease in total oxytoc in mRNA content in this nucleus. The data are compatible with the sugg estion that in AIDS the biosynthesis of oxytocin is changed in an unkn own way at the (post)transcriptional level.