Leitão João Paulo de Vasconcelos, Santos Jefferson Menezes Viana, Vasconcelos Raquel Cavalcante de, Garcia José Huygens Parente, Vasconcelos Paulo Roberto Leitão de, Guimarães Sergio Botelho
Department of Surgery, Federal University of Ceara, Rua Professor Costa Mendes 1608, Fortaleza-CE, Brazil.
Acta Cir Bras. 2011;26 Suppl 1:21-5. doi: 10.1590/s0102-86502011000700005.
To investigate the effect of alanyl-glutamine dipeptide (L-Ala-Gln) pre-treatment on ischemia-reperfusion (I/R) injury after unilateral testicular torsion-detorsion in a comparative controlled experiment.
Forty-eight rats (150-200 g) randomly distributed into 4 groups (n=12), and distributed in 2 subgroups (n=6) each, were treated with saline 2.0 ml (G-1, G-3) or L-Ala-Gln 20%, 0.75g/kg dissolved in saline (total volume 2.0 ml) administered in the left saphenous vein 30 minutes before ischemia. Anesthetized rats were subjected to I/R induced by torsion (720°) of the right spermatic cord lasting 1h (G-1, G-2) or 3 hours (G-3, G4). Anesthesia was again applied at the end of ischemia time (T-0) for testis detorsion and 6 hours later (T-6) for orchiectomy. All operations were performed on the right testes through transverse scrotal incisions. Right orchiectomy was carried out at the end of ischemia (T-0), and 6 hours later (T-6) to evaluate the concentrations of malondialdehyde (MDA) and reduced glutathione (GSH) in the testis.
Pretreatment with L-Ala-Gln reduced MDA contents in rat testis at the end of ischemia lasting 3 hours. There was significant increase of GSH levels in T-6 time-point after 1 hour of ischemia. GSH levels also increased in T-0 and T-6 time-points in rats subjected to ischemia for 3 hours.
L-Ala-Gln administered before torsion/detorsion of the spermatic cord decreases lipid peroxidation during ischemia and protects the testis from oxidative stress by upregulating GSH levels during reperfusion.
在一项比较对照实验中，研究丙氨酰谷氨酰胺二肽（L-丙氨酰-L-谷氨酰胺）预处理对单侧睾丸扭转-复位后缺血再灌注（I/R）损伤的影响。
将48只体重150 - 200克的大鼠随机分为4组（每组n = 12），每组再分为2个亚组（每组n = 6），分别经左隐静脉给予2.0毫升生理盐水（G-1、G-3组）或溶解于生理盐水中的20% L-丙氨酰-L-谷氨酰胺（0.75克/千克，总体积2.0毫升），于缺血前30分钟给药。麻醉后的大鼠通过扭转右侧精索720°诱导I/R，持续1小时（G-1、G-2组）或3小时（G-3、G4组）。在缺血结束时（T-0）再次麻醉以进行睾丸复位，并在6小时后（T-6）进行睾丸切除。所有手术均通过阴囊横向切口在右侧睾丸进行。在缺血结束时（T-0）和6小时后（T-6）进行右侧睾丸切除，以评估睾丸中丙二醛（MDA）和还原型谷胱甘肽（GSH）的浓度。
L-丙氨酰-L-谷氨酰胺预处理可降低缺血持续3小时结束时大鼠睾丸中的MDA含量。缺血1小时后，T-6时间点GSH水平显著升高。在缺血3小时的大鼠中，T-0和T-6时间点的GSH水平也升高。
在精索扭转/复位前给予L-丙氨酰-L-谷氨酰胺可减少缺血期间的脂质过氧化，并通过在再灌注期间上调GSH水平来保护睾丸免受氧化应激。
