Effects of propylthiouracil on growth hormone and prolactin messenger ribonucleic acids in the rat pituitary
Lloyd, R.V.; Jin, L.; Song, J.Y.; Terry, L.C.; Horvath, E.; Kovacs, K.
Laboratory Investigation; A Journal of Technical Methods and Pathology 62(3): 347-354
1990
ISSN/ISBN: 0023-6837 PMID: 2314053 Document Number: 364058
The effects of hypothyroidism induced by propylthiouracil (PTU) treatment on somatotropin (GH) and prolactin (PRL) mRNA levels were analysed in adult female rat adenohypophyses by in situ hybridization histochemistry and Northern hybridization analyses. 28 days of PTU treatment produced a significant decrease in GH mRNA levels and a smaller decrease in PRL mRNA, determined by both in situ hybridization histochemistry and Northern hybridization analyses. A combined procedure of in situ hybridization histochemistry followed by immunochemistry on the same sections revealed mammosomatotropic cells expressing GH mRNA and PRL protein in the same pituitary cells from all treatment groups. Cells expressing GH mRNA and thyroid-stimulating hormone protein were not detected by this method. Immunochemical staining revealed a decrease in GH cells and an increase in thyroid-stimulating hormone cells in hypothyroid rats. Cells expressing both GH and thyroid-stimulating hormone protein were not detected by immunostaining. These results indicate that hypothyroidism produces significant decreases in GH mRNA and also decreases PRL mRNA, and that mammosomatotropic cells can be detected in pituitaries from normal and hypothyroid rats.