急性氨氮胁迫和恢复后中华条颈龟主要器官组织结构的变化

氨氮是水产养殖过程中最主要的环境污染物之一。为探究急性氨氮胁迫对中华条颈龟主要器官组织结构的影响,以体质量(218.26±12.65)g的1龄中华条颈龟为对象,应用苏木精—伊红染色的方法研究氨氮(200 mg/L)胁迫(24、48 h)及去除氨氮(48 h)对其脑、肝脏、心脏、肾脏和脾脏组织结构的影响。试验结果显示,氨氮胁迫后脑组织出现间质增宽、疏松,神经元细胞核发生偏位,神经元变性、坏死等现象,恢复48 h后神经元肿胀与细胞核偏位现象减少;肝脏出现肝细胞肿胀、颗粒变性、水泡变性、坏死等病理现象,肝血窦缩小甚至消失,恢复48 h后肝细胞肿胀减少,肝血窦基本恢复到胁迫前水平,但肝细胞颗粒变性、水泡变性现象依旧存在;心脏间质血管充血,恢复48 h后心肌细胞间隙缩小趋于胁迫前水平,充血现象消失;肾脏肾小管上皮细胞发生颗粒变性,部分细胞从基膜脱落,细胞膜破裂,肾小球体积增大、毛细血管网扩张,细胞核固缩甚至溶解消失,间质中有炎性细胞浸润,恢复48 h后炎性细胞基本消失,但肾小管管腔不规则和颗粒变性等病理现象依旧存在;脾脏白髓区域增大,恢复48 h后白髓与红髓趋于正常水平。试验结果表明,急性氨氮胁迫对中华条颈龟脑、肝脏、心脏和肾脏均会造成不同程度的损伤,恢复48 h后中华条颈龟主要脏器的病理变化呈现出不同程度的缓解,其中心脏恢复能力较好,脑、肝脏和肾脏恢复能力相对较差;脾脏免疫细胞增殖,表明机体在胁迫后会启动免疫防御机制,以增强机体的免疫能力。试验结果从病理学角度阐述了氨氮胁迫对中华条颈龟的影响,为龟鳖类的健康养殖提供一定的理论依据。

Effects of Acute Ammonia Stress on Tissue Structure of Main Organs of Chinese Striped-Necked Turtle Mauremy s sinensis

In order to explore the effects of acute ammonia nitrogen stress on the tissue structure of main organs,one-year-old Chinese striped-necked turtle Mauremys sinensis with average body weight of(218.26±12.65)g was treated with 200 mg/L total ammonia nitrogen for 24 h,48 h and removal of ammonia nitrogen for 48 h.The effects of ammonia nitrogen stress on the tissue structure of brain,liver,heart,spleen and kidney were studied by H·E staining.The results showed that there were broadening and loosening interstitium,deviation of neuronal nucleus,degeneration and necrosis of neurons after ammonia nitrogen stress,and the phenomenon of neuronal swelling and nuclear deviation was found to be decreased after 48 hours of recovery.Pathological phenomena such as hepatocyte swelling,granular degeneration,vesicular degeneration and necrosis were found in the liver,and the hepatic sinusoid shrunk or even disappeared.After 48 hours of recovery,the hepatocyte swelling was decreased and the hepatic sinusoid basically returned to the pre-stress level.However,the phenomena of hepatocyte granule degeneration and vesicular degeneration still existed;cardiac interstitial vascular congestion,the myocardial intercellular space shrinked to the pre-stress level 48 hours after recovery,and the phenomenon of hyperemia disappeared.Renal tubular epithelial cells had granular degeneration,some cells fell off from the basement membrane,cell membrane ruptured,glomerular volume increased,capillary network dilated,nuclear pyknosis or even dissolution disappeared,and inflammatory cells infiltrated in the interstitium.Inflammatory cells basically disappeared after 48 hours of recovery,but pathological phenomena such as irregular lumen of renal tubules and granular degeneration still existed.The white pulp area of the spleen enlarged,and the white marrow and red marrow tended to the normal level after 48 hours of recovery.It was found that acute ammonia nitrogen stress caused varying degrees of damage to the brain,liver,heart and kidney of Chinese striped-necked turtles,and 48 hours of recovery was not enough for Chinese striped-necked turtle to fully recover under stress,in which the recovery ability of heart was better,the recovery ability of brain,liver and kidney was relatively poor,and the proliferation of immune cells in spleen indicated that the body initiated immune defense mechanism after stress to enhance the immune ability of the body.The findings expounded the effect of ammonia nitrogen stress on Chinese striped-necked turtles from the point of view of pathology,which provided a theoretical basis for the healthy culture of turtles.