Variations among rice cultivars on root oxidation and Cd uptake.

In order to understand the mechanisms on the variation between rice cultivars in Cd uptake and accumulation, two pot soil experiments were conducted with typical rice cultivars that varied greatly in soil Cd uptake. The experiments with six rice cultivars showed that the root oxidation abilities of rice differed with rice cultivars and also with types of the cultivars, the cultivars with indica consanguinity were significantly higher than the cultivars with japonica consanguinity. Root oxidation abilities of the rice cultivars correlated positively and significantly (P < 0.01) with their Cd concentrations and Cd quantity accumulations in rice plants. The experiments with two rice cultivars showed that significant differences also existed between the two cultivars in pot soil redox potentials, which of Shan you 63 (higher soil Cd accumulator) were significantly higher than that of Wu yun jing 7 (lower soil Cd accumulator) under different soil Cd levels, but the degrees of the differences varied with soil Cd levels. The differences were larger under soil Cd treatments than the control. The results indicate that root oxidation ability, especially in Cd contaminated soil, is one of the main mechanisms which dominate Cd uptake and accumulation by rice plant.

[Relationship between bleomycin-induced pulmonary fibrosis and vascular endothelial cell injury].

OBJECTIVE: To explore the relationship between the injury of vascular endothelial cells and formation of lung fibrosis by bleomycin (BLM) in rats. METHODS: The rats of experimental groups were treated with bleomycin intratracheally to induce pulmonary fibrosis. The expression of vascular endothelial growth factor (VEGF) in pulmonary tissues were analyzed qualitatively and quantitatively by immunohistochemistry and image analysis system. RESULTS: (1) HISTOLOGY: Edema in rat alveoli and alveolar septum, inflammatory cells exudation, degeneration and necrosis of type I and type II alveolar epithelial cells (AETI and AETII), ruptured alveolar basement membrane, as well as swollen vascular endothelial cells and karyopyknosis were observed in 3 d and 7 d after treatment with BLM. AETII proliferation, with more fibroblasts in alveolar septum, and new capillary vessel formation in 7, 14 d, as well as thickened alveolar septum, damaged alveolar structure, and obvious pulmonary tissue fibrosis in 28 d after treatment with BLM were observed. (2) Immunohistochemistry: in normal control, VEGF expressed weakly in pulmonary tissue distributing mainly in AETII, bronchial epithelial cells, alveolar macrophages and leydig's cells. While in bleomycin treated groups, the expression of VEGF increased markedly. The expression in AETII, and pulmonary macrophage were significantly higher than that in control in 3 d to 28 d (P < 0.05, P < 0.01). The rat leydig's cells also had higher expression of VEGF in 7, 14, 28 d (P < 0.05, P < 0.01). CONCLUSION: The high expression of VEGF is related to vascular endothelial cells injury which may be one of important factors in the formation of bleomycin-induced pulmonary fibrosis.

The study between the dynamics and the X-ray anatomy and regularizing effect of gallbladder on bile duct sphincter of the dog.

AIM: To study the relationship between the radiological anatomy and the dynamics on bile duct sphincter in bile draining and regularizing effect of gallbladder. METHODS: Sixteen healthy dogs weighing 18 kg to 25 kg were divided randomly into control group and experimental group (cholecystectomy group). Cineradiography, manometry with perfusion, to effect of endogenous cholecystokinin and change of ultrastructure were employed. RESULTS: According to finding of the choledochography and manometry, in control group the intraluminal basal pressure of cephalic cyclic smooth muscle of choledochal sphincter cCS was 9.0+/-2.0 mmHg and that of middle oblique smooth muscle of choledochal sphincter (mOS) was 16.8+/-0.5 mmHg, the intraluminal basal pressure of cCS segment was obviously lower than that of mOS (P<0.01) in the interval period of bile draining, but significative difference of intraluminal basal pressure of the mOS segment was not found between the interval period of bile draining (16.8+/-0.5 mmHg) and the bile flowing period (15.9+/-0.9 mmHg) (P>0.05). The motility of cCS was mainly characterized by rhythmically concentric contraction, just as motility of cCS bile juice was pumped into the mOS segment in control group. And motility of mOS segment showed mainly diastolic and systolic activity of autonomically longitudinal peristalsis. There was spasmodic state in cCS and mOS segment and reaction to endogenous cholecystokinin was debased after cholecystectomy. The change of ultrastructure of cCS portion showed mainly that the myofilaments of cell line in derangement and mitochondria is swelling. CONCLUSION: During fasting, the cCS portion has a function as similar cardiac "pump" and it is main primary power source in bile draining, and mOS segment serves mainly as secondary power in bile draining. The existence of the intact gallbladder is one of the important factors in guaranteeing the functional coordination between the cCS and mOS of bile duct sphincter. There is dysfunction in the cCS and mOS with cholecystectomy.

Effect of cholesterol liposomes on calcium mobilization in muscle cells from the rabbit sphincter of Oddi.

AIM: To analyze the influence of cholesterol liposome on the Ca2+ mobilization of cultured muscle cells in the rabbit sphincter of Oddi's. METHODS: New Zealand rabbit was sacrificed and the sphincter of Oddi (SO) segment was obtained aseptically. The SO segment was cut into pieces and cultured in DMEM solution. Then the smooth muscle cells were subcultured, and the 4th-7th passage cells were used for further investigation. The intracellular Ca2+ increase was measured under confocal microscope after the addition of 20 mmol x L(-1) KCl, 10(-7) mol x L(-1) acetylcholine and 10(-7) mol x L(-1) cholecystokinin, and different antagonists were added to analyze the Ca2+ mobilization pathway. After the cells were incubated with 1g x L(-1) cholesterol liposome (CL)(molar ratio was -2:1), the intracellular Ca2+ increase was measured again to determine the effect of CL on cellular Ca(2+) mobilization. RESULTS: The resting cellular calcium concentration of cultured SO cell was 108+/-21 nmol x L(-1).The intracellular Ca2+ increases induced by 20 mmol x L(-1) KCl, 10(-7) mol x L(-1) ACh and 10(-7) mol x L(-1) CCK were 183+/-56% 161+/-52% and 130+/-43%, respectively. When the extracellular Ca2+ was eliminated by 2 mmol x L(-1) EGTA and 5 micromol x L(-1) verapamil, the intracellular Ca2+ increases induced by KCl, ACh and CCK were 20+/-14%,82+/-21% and 104+/-23%, respectively. After the preincubation with heparin, the Ca2+ increases were 62+/-23% and 23+/-19% induced by ACh and CCK, as for preincubation with procaine they were 72+/-28% and 85+/-37% induced by ACh and CCK, respectively. Pretreatment with CL for 18 h, the resting cellular Ca2+ concentration elevated to 152+/-26 nmol x L(-1), however, the cellular Ca2+ increase percentages in response to these agonists were 67+/-32%,56+/-33% and 34+/-15%. CONCLUSION: KCl elicit the SO cellular Ca2+ increase depends on influx of extracellular Ca2+, ACh evoked the SO cellular Ca2+ increase is through the mobilization of intracellular Ca2+ pool and influx of extracellular Ca2+ as well, CCK excites the SO cells mainly through mobilization of intracellular IP3-sensitive Ca2+ store. After the incorporation with cholesterol liposome, KCl,ACh and CCK induced cellular Ca2+ increase percentages decreased.