Department of Pharmacology, Medical Faculty, Inonu University, Malatya, Turkey.
Eur Rev Med Pharmacol Sci. 2012 Jul;16(7):860-6.
It is generally agreed that physiological levels of melatonin, a hormone secreted by the pineal gland, are important in protecting against oxidative stress-induced tissue damage.
We investigated the effects that pinealectomy and the administration of exogenous melatonin have on the brains, testes, duodena and stomachs of rats.
Pinealectomized (Px) and sham-operated (non-Px) rats were used. We evaluated structural changes, and catalase (CAT), reduced glutathione (GSH), super oxide dismutase (SOD) and malondialdehyde (MDA) levels. The rats were divided into the following five groups (eight rats in each group): sham (non-Px), Px+ vehicle, Px+ melatonin (10 mg/kg given daily intraperitoneally for a week), melatonin and ethyl alcohol.
The antioxidant levels in the tissue of Px rats were significantly lower than in those of the sham group. Administering melatonin significantly increased antioxidant levels (p < 0.05). The Px rats also showed a significant increase in MDA levels when compared to the sham group, and administering melatonin to the Px rats significantly reduced their MDA levels (p < 0.05). The severity of caspase-3 staining was lower in the Px+ melatonin group than in the Px+vehicle group.
These findings suggest that significantly more oxidative and structural changes occur in rats' brains, spinal cords and testes after pinealectomy, but that this can be diminished by melatonin treatment. However, Px does not have important effects on the duodenum and stomach.
人们普遍认为，松果腺分泌的激素褪黑素的生理水平对于防止氧化应激引起的组织损伤很重要。
我们研究了松果体切除术和外源性褪黑素给药对大鼠脑、睾丸、十二指肠和胃的影响。
使用了松果体切除术（Px）和假手术（非 Px）大鼠。我们评估了结构变化以及过氧化氢酶（CAT）、还原型谷胱甘肽（GSH）、超氧化物歧化酶（SOD）和丙二醛（MDA）水平。大鼠分为以下五组（每组 8 只）：假手术（非 Px）、Px+载体、Px+褪黑素（10mg/kg 每日腹腔内给药一周）、褪黑素和乙醇。
Px 大鼠组织中的抗氧化水平明显低于假手术组。给予褪黑素可显著提高抗氧化水平（p<0.05）。与假手术组相比，Px 大鼠的 MDA 水平也显著升高，给予 Px 大鼠褪黑素可显著降低其 MDA 水平（p<0.05）。与 Px+载体组相比，Px+褪黑素组 caspase-3 染色的严重程度较低。
这些发现表明，松果体切除后大鼠脑、脊髓和睾丸发生了更严重的氧化和结构变化，但褪黑素治疗可以减轻这种变化。然而，Px 对十二指肠和胃没有重要影响。
