Celik Ismail, Tuluce Yasin, Isik Ismail
Yuzuncu Yil University, Faculty of Arts and Sciences, Department of Biology, Van, Turkey.
J Enzyme Inhib Med Chem. 2007 Apr;22(2):219-26. doi: 10.1080/14756360600988955.
In the present study, the influence of subchronic effects of two plant growth regulators (PGRs) [Abcisic acid (ABA) and Gibberellic acid (GA3)] on antioxidant defense systems [reduced glutathione (GSH), glutathione reductase (GR), superoxide dismutase (SOD), glutathione-S-transferase (GST) and catalase (CAT)] and lipid peroxidation level (malondialdehyde = MDA) in various tissues of the rat were investigated during treatment as a drinking water model. 75 ppm of ABA and GA3 in drinking water were continuously administered orally to rats (Sprague-Dawley albino) ad libitum for 50 days. The PGRs treatments caused different effects on the antioxidant defense systems and MDA content of dosed rats compared to controls. The lipid peroxidation end product MDA significantly increased in the lungs, heart and kidney of rats treated with GA3 without significant change in the spleen. ABA caused also a significant increase in MDA content in the spleen, lungs, heart and kidney. The GSH levels were significantly depleted in the spleen, lungs and stomach of rats treated with ABA without any change in the tissues of rats treated with GA3 except the kidney where it increased. Antioxidant enzyme activities such as SOD significantly increased in the lungs and stomach and decreased in the spleen and heart tissues of rats treated with GA3. Meanwhile, SOD significantly decreased in the spleen, heart and kidney and increased in the lungs of rats treated with ABA. While CAT activity significantly decreased in the lungs of rats treated with GA3, a significant increase occurred in the heart of rats treated with both PGRs. On the other hand, the ancillary enzyme GR activity in the tissues were either significantly depleted or not changed with PGRs treatment. The drug metabolizing enzyme GST activity significantly decreased in the lungs of rats treated with ABA but increased in the stomach of rats treated with both PGRs. As a conclusion, the rats resisted oxidative stress via the antioxidant mechanism. But the antioxidant mechanism could not prevent the increases in lipid peroxidation in rat's tissues. This data, along with changes, suggests that PGRs produced substantial systemic organ toxicity in the spleen, lungs, stomach, heart and kidney during a 50-day period of subchronic exposure.
在本研究中，作为饮水模型，研究了两种植物生长调节剂[脱落酸（ABA）和赤霉酸（GA3）]的亚慢性效应，对大鼠不同组织中抗氧化防御系统[还原型谷胱甘肽（GSH）、谷胱甘肽还原酶（GR）、超氧化物歧化酶（SOD）、谷胱甘肽 - S - 转移酶（GST）和过氧化氢酶（CAT）]以及脂质过氧化水平（丙二醛 = MDA）的影响。以75 ppm的ABA和GA3持续添加于饮用水中，随意口服给予大鼠（斯普拉 - 道利白化大鼠），持续50天。与对照组相比，植物生长调节剂处理对给药大鼠的抗氧化防御系统和MDA含量产生了不同影响。用GA3处理的大鼠，其肺、心脏和肾脏中的脂质过氧化终产物MDA显著增加，而脾脏中无显著变化。ABA也导致大鼠脾脏、肺、心脏和肾脏中的MDA含量显著增加。用ABA处理的大鼠，其脾脏、肺和胃中的GSH水平显著降低，而用GA3处理的大鼠组织中，除肾脏中GSH水平升高外，其他组织无变化。用GA3处理的大鼠，其肺和胃中的抗氧化酶活性如SOD显著增加，而脾脏和心脏组织中则降低。同时，用ABA处理的大鼠，其脾脏、心脏和肾脏中的SOD显著降低，而肺中则增加。在用GA3处理的大鼠肺中，CAT活性显著降低，而在用两种植物生长调节剂处理的大鼠心脏中，CAT活性显著增加。另一方面，组织中的辅助酶GR活性在用植物生长调节剂处理后，要么显著降低，要么没有变化。药物代谢酶GST活性在用ABA处理的大鼠肺中显著降低，但在用两种植物生长调节剂处理的大鼠胃中增加。总之，大鼠通过抗氧化机制抵抗氧化应激。但抗氧化机制无法阻止大鼠组织中脂质过氧化的增加。这些数据以及变化表明，在50天的亚慢性暴露期间，植物生长调节剂在脾脏、肺、胃、心脏和肾脏中产生了实质性的全身器官毒性。
