Vugman I, Hand A R
Clinical Investigations and Patient Care Branch, National Institute of Dental Research, National Institutes of Heatlh, Bethesda, Maryland 20892, USA.
Microsc Res Tech. 1995 Jun 1;31(2):106-17. doi: 10.1002/jemt.1070310203.
Chronic treatment of mice and rats with isoproterenol (IPR) causes marked hypertrophy and hyperplasia of the salivary glands, and alters the expression of several secretory proteins. We used quantitative postembedding immunogold labeling to study the cellular responses in the rat parotid gland during daily (up to 10 days) injections of IPR and during recovery (up to 14 days) after cessation of IPR treatment. Labeling densities of acinar cell secretory granules with antibodies to amylase and protein SMG-B1 (cross-reactive with the rat homologue of Parotid Secretory Protein, PSP) fell to 10% of control levels after 8-10 IPR injections, then increased during recovery, paralleling previous biochemical determinations of changes in protein and mRNA levels. With antibodies to proline-rich proteins (PRP), labeling densities initially fell, then subsequently showed considerable variability, but never exceeded control levels. These results contrast with biochemical determinations showing a marked induction of PRP synthesis, and may have both immunological and structural explanations. Occasional intercalated duct cells located close to the acini underwent differentiation toward an acinar-like phenotype as a result of IPR treatment. After 1-2 IPR injections, the secretory granules of these cells labeled with antibodies to amylase and PRP. Subsequently, the granules appeared electron-lucent and were increased in size and number. These observations support earlier work, suggesting that intercalated duct cells may differentiate into other gland cell types.
用异丙肾上腺素（IPR）对小鼠和大鼠进行长期治疗会导致唾液腺显著肥大和增生，并改变几种分泌蛋白的表达。我们使用定量包埋后免疫金标记法，研究了大鼠腮腺在每日注射IPR（长达10天）期间以及IPR治疗停止后的恢复阶段（长达14天）的细胞反应。用淀粉酶抗体和蛋白SMG-B1（与腮腺分泌蛋白PSP的大鼠同源物交叉反应）对腺泡细胞分泌颗粒进行标记，在注射8 - 10次IPR后，标记密度降至对照水平的10%，然后在恢复期间增加，这与先前对蛋白质和mRNA水平变化的生化测定结果一致。用富含脯氨酸蛋白（PRP）抗体检测时，标记密度最初下降，随后表现出相当大的变异性，但从未超过对照水平。这些结果与显示PRP合成显著诱导的生化测定结果形成对比，可能有免疫学和结构学两方面的解释。偶尔靠近腺泡的闰管细胞因IPR治疗而向腺泡样表型分化。注射1 - 2次IPR后，这些细胞的分泌颗粒用淀粉酶和PRP抗体标记。随后，颗粒呈现电子透明，大小和数量增加。这些观察结果支持了早期的研究工作，表明闰管细胞可能分化为其他腺细胞类型。
