Radioprotection of the murine submandibular gland by isoproterenol: autoradiography study with 3H-leucine.
Irradiation of the salivary glands results in the generation of free radicals from metal ions present in the secretory granules of acinar cells, a process that is believed to exacerbate radiation damage to the salivary glands. We therefore conducted a comparative investigation of radiation damage to the acinar cells of murine submaxillary glands in which granule secretion had been induced, and used autoradiography to visualize the pathological changes. Male BALB/c mice, at 8 weeks of age, were divided into four groups: a no-isoproterenol (IPR) and no-irradiation group (group I), a no-IPR, irradiated group (group II), an IPR, no-irradiation group (group III), and an IPR, irradiated group (group IV). Intraperitoneal injections of IPR were used, and 3 h later, the submaxillary region was irradiated with X-rays at a dose of 10 Gy. Three days after the irradiation, 3H-leucine was administered, and submaxillary glands were removed at predetermined times. Thin sections were prepared, and light- and electron-microscope autoradiography was performed. The number of reduced silver particles per unit acinar cell area was determined by light-microscopic autoradiography, and the proportion of reduced silver particles in the rough endoplasmic reticulum, the Golgi apparatus, and secretion granules was determined by electron-microscopic autoradiography. The result indicated that the effects of the radiation on the secretory potential of the submaxillary glands were diminished in acinar cells with a higher secretory granule content.
Aonuma
Mitsuhiro
M
Department of Oral and Maxillofacial Radiology, The Nippon Dental University, School of Dentistry at Tokyo, 2-3-16, Fujimi, Chiyoda-ku, Tokyo, Japan.
Nasu
Masanori
M
Iwata
Hiroshi
H
Yosue
Takashi
T
D000318:Adrenergic beta-Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001345:Autoradiography; D018870:Endoplasmic Reticulum, Rough / Q000187:drug effects / Q000528:radiation effects; D006056:Golgi Apparatus / Q000187:drug effects / Q000528:radiation effects; D007274:Injections, Intraperitoneal; D007545:Isoproterenol / Q000008:administration & dosage / Q000494:pharmacology*; D007930:Leucine; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D011829:Radiation Dosage; D011837:Radiation-Protective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D019275:Radiopharmaceuticals; D011897:Random Allocation; D022142:Secretory Vesicles / Q000187:drug effects / Q000528:radiation effects; D013363:Submandibular Gland / Q000187:drug effects / Q000528:radiation effects* / Q000648:ultrastructure; D013997:Time Factors; D014316:Tritium; D014965:X-Rays
D000318:Adrenergic beta-Agonists; D011837:Radiation-Protective Agents; D019275:Radiopharmaceuticals; D014316:Tritium; D007930:Leucine; D007545:Isoproterenol