Matsuura S, Suzuki K
Department of Oral Histology, Matsumoto Dental College, Shiojiri, Japan.
J Histochem Cytochem. 1997 Aug;45(8):1137-45. doi: 10.1177/002215549704500811.
We investigated the numbers of DNA-synthesizing cells in mouse submandibular glands (SMGs) during chronic isoproterenol (IPR) administration, using an immunohistochemical method with anti-bromodeoxyuridine (BrdU) antibodies. Adult and immature female mice were injected with IPR daily or every other day up to a total of seven injections. Whereas hypertrophic enlargement of acinar cells continued with repeated IPR injections, induction of DNA synthesis was transient. With one IPR injection, more than 50% of the acinar cells were induced to synthesize DNA, but after five daily injections the numbers of cells in the DNA synthetic phase decreased and returned to control values. This pattern was basically the same for immature mice and for adult mice stimulated by IPR every other day. The responsiveness of the SMGs of immature mice to IPR was somewhat lower than that of adults. Prolongation of the interval between injections of IPR, compared to daily injections, did not cause sustained induction of DNA synthesis. These data suggest that the hypertrophic enlargement and the induction of DNA synthesis by IPR are mediated through different intracellular pathways after the stimulation of beta-adrenergic receptors, and that the regulatory mechanism for the induction of DNA synthesis is complex.
我们采用抗溴脱氧尿苷（BrdU）抗体免疫组织化学方法，研究了慢性给予异丙肾上腺素（IPR）期间小鼠颌下腺（SMG）中DNA合成细胞的数量。成年和未成年雌性小鼠每天或隔天注射IPR，共注射七次。尽管反复注射IPR会使腺泡细胞持续出现肥大性增大，但DNA合成的诱导是短暂的。单次注射IPR后，超过50%的腺泡细胞被诱导合成DNA，但每日注射五次后，处于DNA合成期的细胞数量减少并恢复到对照值。未成年小鼠以及隔天接受IPR刺激的成年小鼠的情况基本相同。未成年小鼠的SMG对IPR的反应性略低于成年小鼠。与每日注射相比，延长IPR注射间隔时间并不会导致DNA合成的持续诱导。这些数据表明，IPR引起的肥大性增大和DNA合成诱导是通过β-肾上腺素能受体刺激后不同的细胞内途径介导的，并且DNA合成诱导的调节机制很复杂。
