| The freshwater crab is widely distributed in Chinese freshwater area, while the Sinopotamon yangtsekiensei is a kind of representative one of the freshwater crab. Effects of heavy metal, such as Cd2+ and Pb2+, on the species can reflect the effects of the water pollution of heavy metal on the Decapodas(Crustacea:) to some extent.Based on the lexicological biochemistry and ultrastructure, effects of heavy mental on 5. yangtsekiense had been studied in this paper by means of transmission electronmicroscope (TEM) and polyacrylamide gel electrophoresis(PAGE). There are four sections in this experiment.Section 1: After an experimental exposure to low dosage of Cd2+ (1.87mg/LCd2+ concentration ) for 30 days, the changes of Cd2+on ultrastructure of the hepatopancreas cells of the male freshwater crab S. yangtsekiense at three different times was studied by using transmission electro-microscopy(TEM).The results show that the nuclear membrane changed from spreading all over the place to disintegrated, and the penetration of the mitochondria! outer membrane and inner membrane was changed. So the mitochondria showed swelling and vacuolating. Mitochondria! cristae partly disintegrated, then fully disintegrated. Besides, the Cd2* exposure affected the gross form and the structure of the rough endoplasmic reticulum (RER). First, the RER became the diflferent size vesicles, then, the ribosomes on the little vesicles began to fall, and finally, the RER turned to the concentric round lamellar structures. But the smooth endoplasmic reticulum (SER) increased heavily. In addition, the numbers and types of lysosome were increased in the mean time and some lysosomes became void vesicles, the autophagiosomea or the myeloid bodies(MD). The microvilli showed partly falling and vacuolating. After the Cadmium making the detoxification mechanism of the freshwater crab to lose the function, the structural and functional integrality of the mostly organelles, such as the nucleous, the mitochondria and the rough endoplasmic reticulum, was destroyed.Section 2: The effects of cadmium on myocardial cell and male sex-cell in freshwater crab S. yangtsekiense were studied by means of body cavity injection(1.5 u gCd2+/g body weight) and exposure(1.87mg/LCd2+concentration) in this paper. The myocardial cells and the male germ cells at the different developmental stages during spermatogenesis in the treated and control individuals had been observed by transmission electron microscopy (TEM) in order to determinewhether cadmium might have a morphological effect on them. The same experiment had been done twice.The results showed that all kinds of observed cells had been changed ultrastructurally after cadmium treatment whether by injection or by exposure, and that the longer of cadmium treatment was, the more seriously the cells had been changed in morphology. The results showed that myocardial cells and male germ cells of the experimented animals could be damaged whether by injection cadmium into their body cavity or by exposing cadmium. The organelles with membranous structure in myocardial cells and germ cells were easily damaged, such as mitochondria, nucleus, Golgi body (GB) and lysosome. Among them, mitochondria was damaged earliest, which suggested that mitochondria was a sensitive organelle to cadmium and could show damage decree led to by cadmium. In addition, the myofibrils were found broken in myocardial cells suggested that the structure of actin could be damaged by cadmium.Section 3: This paper dealed with the effects at different dosages of Pb2+ on the Esterase isoenzyme(EST) of the gill, hepatopancreas and ovary by using polyacrylamide gel electrophoresis (PAGE).The results showed that the effects of Pb +on Esterase isoenzyme activity are not only the activation but the inhibity as well. There were different effects of Pb2+ on EST isoenzyme of the major tissues . At different dosages of Pb2+, there was dosage domino effect for the ESTisoenzyme of one tissue. From the results it can be concluded that the EST iso...
|
PDF Full Text Request