盐度对瘤背石磺不同部位Na /K -ATP酶活性、围心腔液和腹腔液渗透压及离子含量的影响

为了研究盐度对瘤背石磺不同部位Na+/K+-ATP酶活性、围心腔液和腹腔液渗透压及离子含量(Na+、K+和Cl-)的影响,选取健康的瘤背石磺湿重(10.24±2.16)g]600只,在不同盐度条件下(5、15、25、35和45)采用模拟生态环境的方式饲养30 d后测定各项指标.结果显示:(1)瘤背石磺腹腔液和围心腔液的盐度和渗透压均随着环境盐度的升高而增高,腹腔液的盐度和渗透压的变动幅度分别为25～ 43和514 ～ 796 mOsm/kg,其增高幅度均大于围心腔液(分别为23 ～ 28和502～ 726 mOsm/kg)；(2)围心腔液中Na+、Cl-和K+含量随环境盐度的变化具有一致性,均呈先上升后下降的趋势,且各离子浓度均在盐度25时达到最大值,分别为295.50、322.50和5.15 mmol/L,但盐度对Na+和Cl-含量有显著影响,对K+含量无显著影响.(3)瘤背石磺不同部位的Na +/K+-ATP酶活性具有组织特异性,贲门胃、肠、表皮、肌肉和围心腔膜等部位的Na +/K+-ATP酶活性较高,同时,盐度激活不同部位的Na +/K+-ATP酶活性具有显著差异性,肌肉和贲门胃的Na +/K+-ATP酶在低盐度时活性较高,而肠、肾及围心腔膜等在高盐度时Na+/K+-ATP酶被激活,酶活性较高.研究表明:盐度能显著影响瘤背石磺腹腔液和围心腔液的渗透压和离子浓度以及各器官的Na+/K+-ATP酶活性,贲门胃、肠和肌肉等均是其离子转运和渗透调节的主要部位,具有较强的渗透压调节能力.

Effects of salinity on Na /K -ATPase activity, the osmolality of pericardial cavity fluid and peritoneal fluid and ion content of Onchidium struma

To explore the effects of salinity on the Na /K -ATPase activity, the osmolality of pericardial cavity fluid and peritoneal fluid and ion content (Na , K and Cl-) in Onchidium struma, six hundred healthy specimens (wet weight 10.24 ± 2.16 g) were selected and had been raised for 30 days with simulated ecological environments that in different salinity conditions (5, 15, 25, 35 and 45). The results shows: 1) The salinity and osmolality of peritoneal fluid and pericardial cavity fluid of Onchidium struma are increased with increasing ambient salinity, and the increased amplitude of peritoneal fluid all greater than the pericardial cavity fluid. 2) The content of Na , Cl- and K of pericardial cavity fluid consistent with the changes of ambient salinity and these are all increased firstly then decreased. The concentrations of Na , Cl- and K reached the maximum at salinity 25 and salinity has a significant impact on Na and Cl- but with no significant effect on K . 3) There are significant differences on Na /K -ATPase activity of different parts in Onchidium struma. The Na /K -ATPase in cardia stomach, intestine, epidermis, muscle and pericardial cavity film of Onchidium struma have higher activity. In addition, the Na /K -ATPase activity of different parts activated by salinity with some tissue-specificity, there are higher activity of hepatopancreas, cardia stomach and epidermis in low salinity while the pyloric stomach, intestine, kidney and pericardial cavities film in high salinity. These results indicates that the salinity can significantly impact the osmolality and ion concentration of peritoneal fluid and pericardial cavity fluid as well as the Na /K -ATPase activity of Onchidium struma. The cardia stomach, intestine and muscle are main organs involved in its ion transport and osmoregulation with strong osmotic adjustment capability.