Departamento de Biomateriais e Biologia Oral, Faculdade de Odontologia, Universidade de São Paulo (USP), São Paulo, Brazil, 05508-000.
Lasers Med Sci. 2013 May;28(3):911-8. doi: 10.1007/s10103-012-1173-5. Epub 2012 Aug 7.
The aim of the present study was to analyze the effect of low-power laser irradiation in the antioxidant enzymatic system of submandibular (SMG) and parotid (PG) salivary glands of streptozotocin-induced diabetic rats. The animals were randomly divided into six groups: three diabetic groups (D0, D5, and D20) and three non-diabetic groups (C0, C5, and C20), according to laser dose received (0, 5, and 20 J/cm(2), respectively). Areas of approximately 1 cm(2) were demarcated in the salivary glands (each parotid and both submandibular glands) and after irradiated according to Simões et.al. (Lasers Med Sci 24:202-208, 2009). A diode laser (660 nm/100 mW) was used, with laser beam spot of 0.0177 cm(2). The group treated with 5 J/cm(2) laser dose was subjected to irradiation for 1 min and 4 s (total irradiation time) and the group treated with 20 J/cm(2) laser dose was subjected to irradiation for 4 min and 16 s. Twenty-four hours after irradiation the animals were euthanized and the salivary glands were removed for biochemical analysis. The total antioxidant values (TA), the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase enzymes were determined. SOD and CAT activities, as well as TA were higher in SMG of irradiated diabetic rats. However, in SMG of non-diabetic rats, laser irradiation decreased TA values and led to an increase in the CAT activity. In addition, there was a decrease in the activity of CAT in PG of diabetic and non-diabetic animals after laser irradiation. According to the results of the present study, low-power laser irradiation can affect the enzymatic antioxidant system of salivary glands of streptozotocin-induced diabetic rats.
本研究旨在分析低强度激光照射对链脲佐菌素诱导的糖尿病大鼠下颌下（SMG）和腮腺（PG）唾液腺抗氧化酶系统的影响。动物随机分为六组：三组糖尿病组（D0、D5 和 D20）和三组非糖尿病组（C0、C5 和 C20），根据接受的激光剂量（分别为 0、5 和 20 J/cm²）。按照 Simões 等人的方法（Lasers Med Sci 24:202-208, 2009），在唾液腺（每个腮腺和两个下颌下腺）上划出约 1 cm² 的区域。使用二极管激光器（660nm/100mW），激光光斑为 0.0177cm²。接受 5J/cm²激光剂量的组接受 1 分 4 秒（总辐照时间）的照射，接受 20J/cm²激光剂量的组接受 4 分 16 秒的照射。照射后 24 小时处死动物，取出唾液腺进行生化分析。测定总抗氧化值（TA）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽过氧化物酶活性。糖尿病大鼠 SMG 中 SOD 和 CAT 活性以及 TA 升高。然而，在非糖尿病大鼠的 SMG 中，激光照射降低了 TA 值并导致 CAT 活性增加。此外，激光照射后糖尿病和非糖尿病动物的 PG 中 CAT 活性下降。根据本研究的结果，低强度激光照射可以影响链脲佐菌素诱导的糖尿病大鼠唾液腺的酶抗氧化系统。
