본 연구는 phenylephrine과 isoproterenol을 지속적으로 투여한 후 흰쥐의 턱밑샘의 도관부로부터 성장인자를 분비시킨 후 턱밑샘에서 상피성장인자 수용체와 신경성장인자 수용체의 분포특성을 면역조직화학방법을 이용하여 알아봄으로써 상피성 장인자와 신경성장인자의 생리적인 기능을 구명하고자 수행되었다. Phenylephrine을 투여한 군에서는 광학현미경적으로 뚜렷한 변화를 관찰할 수 없었으나 isoproterenol을 투여한 군에서는 투여기간에 따라 샘조직의 현저한 증식을 관찰할 수 있었다. 상피성장인자 수용체는 상피성장인자가 존재하는 것으로 알려진 도관 벽세포에 분포하고 있었으나 이들은 isoproterenol 투여 직후 증가하였다가 투여기간이 길어질수록 감소하는 경향을 보였다. 신경성장인자 수용체는 도관 주변 결합조직세포에 분포하고 있었으며 phenylephrine 투여 후 증가하는 경향을 보였으나 isoproterenol 투여 후에는 감소하였다. 따라서 상피성장 인자 수용체와 신경성장인자 수용체는 각각 턱밑샘의 도관 벽세포와 도관주변 결합조직에 위치하며 이들은 외분비기전에 의해 구강내로 분비될 뿐만아니라 자가분비 또는 곁분비기전에 의해 샘조직 자체내에서 생리적인 기능을 수행할 것으로 사료된다.
The immunohistochemical localization of epidermal growth factor receptor (EGFR) and nerve growth factor receptor (NGFR) in the submandibular gland of rats was investigated after chronic administration of isoproterenol (IPR) or phenylephrine (PEP). The weight of submandibular gland relative to body weight increased sharply by IPR administration for 14 days and reached twice of that in control, while no significant differences were observed after PEP administration. In PTAH staining, the intensity of duct compartments in rats exposed to IPR and PEP were paler than that of controls. But small secretory granules were observed in the GCT cells of IPR administrated groups. Acini showed characteristic features of hypertrophy, decreased in number of nuclei per unit area, after IPR administration, but not after PEP. EGFR immunoreactivities were distributed mainly in the duct compartments including GCT cells, intercalated duct cells and secretory duct cells. EGFR immunoactivities were more intense after both of PEP and IPR administration than those in controls. However, EGFR immunoactivities gradually decreased after IPR administration. NGFR immunoreactivities were distributed mainly in connective tissue cells surrounding ducts, but not in duct cells. Their intensities increased in the rat with PEP administration but decreased by IPR administration. These results demonstrated that EGFR or NGFR is localized mainly in the duct cells or the cells surrounding ducts, respectively, and that both population of EGFR and NGFR immunoreactive cells are altered by PEP and IPR. The results suggest that EGF and NGF may have some physiological roles by binding with their specific receptors in the submandibular gland as well as oral cavity.
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