Propylthiouracil (PTU) disturbs taste acuity through thyroid hormone inactivation

抄録

　It is well documented that thio-containing antithyroid drug- propylthiouracil (PTU) and hypothyroidism disturb taste acuity in human and experimental animal. We investigated the histology and ultrastructure of vallate taste buds in adult gerbil after intraperitoneal injection of PTU and also in adult gerbil after thyroidectomy. All animals were killed and their vallate papillae were processed for light and electron microscopy as well as morphometric analysis. The results from PTU-treatment and thyroidectomized animals were similar, two types of degenerating cells, i.e. the light-vacuolated cells and the dark-condensed cells, were significantly increased in the gerbil taste buds. The vacuoles that observed in the light-vacuolated cells were identified as dilated endoplasmic reticulum cisternae filled with the flocculent material of low electron density. Dark-condensed cells were characterized by the pyknotic nucleus and their dense cytoplasm. Morphometric analysis revealed that the percentages of type I and type II cells were decreased, and those of light-vacuolated and the dark-condensed degenerating cells were increased corresponding to the decrease of type I and type II cells in the PTU-treatment and thyroidectomized animals. These observations suggest that in gerbil circumvallate taste buds, both PTU-treatment and thyroidectomy induce significant morphological alterations, which may due to the actions of thyroid hormone.