Comparative study of renal sodium transport between ouabain-hypertensive rats and ouabain-nonhypertensive rats

Objective: To compare renal sodium transport, using fractional excretions of lithium(FELi) as a marker of proximal tubule sodium reabsorption, between hypertensive and non-hypertensive ouabain-treated rats and further to elucidate the role of ouabain in pathogenesis of hypertension. Methods: Thirty male Sprague-Dawley rats weighting 180-200 g were randomly divided into normal control group and ouabain treated group. Rats were infused with 1 ml/kg·d normal saline or 27. 8μg/kg·d ouabain in-traperitoneally once a day respectively. Systolic blood pressure (SBP), heart rate and body weight were recorded weekly. Rats were sacrificed 6 weeks after treatment. Blood and 24-hour urine sample were collected to measure the serum and urinary concentration of sodium, trace lithium and creatinine. Endogenous creatinine clearance rate(Ccr), fractional excretions of sodium (FENa), fractional excretions of lithium (FELi) and fractional reabsorption of sodium in the postproximal tubules (FDRNa) were calculated. Ouabain levels of plasma and renal tissue, plasma renin activity, angiotensin I and aldosterone concentration were determined. Results: 65% of the ouabain-treated rats achieved significantly higher SBP after 4 weeks, compared with that of the saline control groups or self baseline (P<0. 01). But in the other 35% of the ouabain-treated rats, their SBP was similar with control group during the experiment (P>0. 05). The body weight, heart rate and food intake between the 3 groups were no significant differences (P> 0. 05). FELi and FDRNa were significantly lower in ouabain-hypertensive group compared with ouabain-non-hypertensive group and control group(P<0. 01 and P<0. 05). The FEu and FDRn, of ouabain-nonhyper-tensive groups were similar with control group(P>0. 05). Ccr and FENa were comparable between the 3 groups (P>0. 05). Plasma and renal tissue ouabain levels, plasma renin activity, angiotensin I and aldosterone contents in ouabain-hypertensive rats were comparable with ouabain-nonhypertensive rats. Conclusion: Increase of proximal tubule sodium reabsorption play an important role in the pathogenesis of ouabain-hypertensive rats. The change of renal sodium transport may result from regulation to renal Na+ , K + -ATPase by ouabain.     

Levocabastine compared with sodium cromoglygate eyedrops in children with both birch and grass pollen allergy

Fifty–five children 6–16 years old with allergic rhinoconjunctivitis due to both birch and grass pollinosis were randomized into 2 parallel groups, treated in double–blind fashion with either levocabastinc (LEV) eye–drops twice daily plus placebo eyedrops twice daily or sodium cromoglycate (SCG) eyedrops 4 times daily for 3 months. Spersallerg® (antazolini chloride + tetryzolini chloride) eyedrops were allowed as rescue medicine. All children received basic treatment with an antihistamine (terfenadine) during the complete trial period, and a local nasal corticosteroid if needed. Eye symptoms were recorded daily by the patients and at 4 visits by the investigator, at start and after 4, 10 and 13 weeks. Pollen counts were performed and a blood sample was collected at start and end of the treatment. The global evaluation of treatment was similar for the 2 groups, and there was no significant difference in any effect parameter except for the symptom, itchy eyes, which had lower score in the SCG group as evaluated by the investigator after 4 weeks. On days with low pollen counts the patients in the SCG group had fewer days with moderate or severe eye symptoms. It is concluded that even though LEV and SCG eyedrops were given in addition to systemic treatment with an antihistamine, no consistently significant differences in clinical effect were found between the 2 treatment groups, but the SCG group experienced slightly less eye symptoms throughout the trial. LEV eye–drops appear safe in long–term treatment in children, and no signs of tachyphylaxis were recorded.     

The effect of sodium lauryl sulphate on the expression of cytokeratin mRNA in hamster cheek pouch epithelium

The effect of sodium lauryl sulphate (SLS) on cytokeratin (CK) gene expression in hamster cheek pouch epithelium was studied with a hybridohistochemical technique. Using specific human anti-sense RNA probes, the plausible hamster mRNA counterparts for these human CK mRNAs were localized by detection of heterologous hybrids. In comparison with normal epithelium, the expression and distribution pattern of CK mRNAs in the hamster cheek pouch were obviously changed after application of SLS. There was a decreased expression of CK mRNAs in the hyperplastic basal layer, and increased expression in the hypertrophic granular layer. Strikingly, hybridization with the human CK 18 cRNA probe revealed an additionally expressed CK mRNA in the SLS-treated epithelium that was not found in the untreated epithelium. The present study indicates that cRNA probes for human CK mRNAs can be used successfully, not only to distinguish between different hamster CK mRNAs but also to investigate changes in CK gene expression upon the induction of non-neoplastic and neoplastic alterations in the hamster cheek pouch model. This may help elucidate the molecular changes involved in epithelial pathologies.     

Reduction in sodium chloride intake: effects on urinary Na, K and aldosterone output in healthy free-living adults

Eleven healthy free-living adults (six women, five men) weighed and recorded all food and drink consumed and collected all urine for two non-consecutive 7-day periods whilst eating their usual diet (Period 1) and attempting to reduce salt intake (Period 2). Bread (including pitta bread) provided on average a quarter of total Na intake of subjects in Period 1 so that wholemeal bread made without added salt was made available in Period 2. All subjects achieved substantial reductions (mean 65%) in Na intake in Period 2 with no change in K intake so that the Na:K molar ratio fell from 1.3 to 0.5. Urinary Na output closely followed intakes and there was a large increase (mean 11.2 μg/d) in aldosterone excretion with a non-significant increase in K output. Simple linear relationships which allow prediction of Na and K intake from the more easily measured urinary output were derived.     

Effects of topical anti-inflammatory drugs on eosinophil survival primed by epithelial cells. Additive effect of glucocorticoids and nedocromil sodium

Background Eosinophil infiltration is a hallmark of the inflammatory response in rhinitis and in nasal polypcsis. Objective We studied the effect of steroids and nedocromil sodium on eosinophil survival primed by epithelial cells from healthy (nasal mucosa) and inflamed (nasal polyp) respiratory tissue. Methods Blood eosinophils were incubated with increasing concentrations (10^-11 10^-5 M) of topical steroids (fiuticasone propionate, budesonide, triamcinolone acetonide and beclomethasone dipropionate) and/or nedocromil sodium prior to the addition of human epithelial cell conditioned media (HECM), eosinophil viability was measured and IC₅₀ for each drug was calculated. Results All four steroids and nedocromil sodium caused a dose-related inhibition of HECM-induced eosinophil survival. The IC₅₀ of steroids were lower in eosinophils primed by mucosa HECM than on those primed by polyp HECM (fluticasone, 4nM vs 114nM: budesonide, 21 nM vs 280 nM; triamcinolone, 7 nM vs 853 nM; and beclomethasone, 171 nM vs 181 nM). The combined inhibitory effect of 10^-7M budesonide plus 10^-5M nedocromil (43.8 ± 10.8%, P < 0.03) was significantly higher than budesonide (28.5 ± 9.2%) or nedocromil (16.7 ± 5.4%) alone and close to 10^-5M budesonide (52.3 ± 11%). No differences were found in cytokine (IL-8, IL-6, GM-CSF, TNFα, IL-lβ and RANTES) concentrations between HECM from mucosa and polyps. Conclusion These results suggest that topical anti-inflammatory drugs may diminish airway eosinophilic infiltration by decreasing eosinophil viability, that nasal polyp epithelial cell secretions may induce steroid resistance in eosinophils, and that nedocromil sodium has additive effects with steroids.     

亚硝酸钠与AFB1相互作用对遗传物质影响的实验研究

以正常人外周血淋巴细胞的ＳＣＥ率作为细胞遗传学指标，研究了Ｎａ＿２ＳｅＯ＿３与ＡＦＢ＿１相互作用对细胞遗传物质的影响。结果表明，一定浓度的Ｎａ＿２ＳｅＯ＿３（１０￣（－５）ｍｏｌ）对ＡＦＢ＿１所诱发的ＳＣＥ有明显的抑制作用，但当浓度达到１０￣（－２）ｍｏｌ时，细胞增殖受到抑制，到１０￣（－１）ｍｏｌ时细胞出现毒性现象。提示Ｎａ＿２ＳｅＯ＿３具有抑变和细胞毒性双相作用。所以在Ｎａ＿２ＳｅＯ＿３与ＡＦＢ＿１相互作用的ＳＣＥ实验中应避免Ｎａ＿２ＳｅＯ＿３的浓度过高而损伤培养的细胞。     

Sodium Valproate-lnduced Cardiovascular Abnormalities in the JchlCR Mouse Fetus

Sodium valproate was administered to Jcl:ICR mice in order to evaluate teratogenicity in the cardiovascular system. A single dose of 600mg/kg of sodium valproate was injected intraperitoneally on gestational day 6, 7, 8 or 9. On day 18 of gestation, dams were laparotomized to observe incidence and type of cardiovascular abnormality in live fetuses. Cardiovascular abnormalities were found most frequently in the group treated on day 7, being recognized in 86% of litters (19/22) and in 29% of live fetuses (70/238). Among these, there were 28 cases of transposition of the great arteries, 13 of double outlet right ventricle, 11 of endocardial cushion defect, 9 of ventricular septal defect, 5 of tricuspid atresia, and 4 of hypoplastic left heart syndrome.     

Diagnosis of the acute ischaemic heart by ion elution from myocardium.

The post-mortem diagnosis of acute myocardial ischaemia may be difficult to establish in the absence of morphological changes in the myocardium or recent coronary thrombosis. Ischaemic cell injury leads to potassium (K) efflux and sodium (Na) influx and, if the blood is still circulating, the K:Na ratio of the tissue falls. In this study, the K:Na ratio was measured by eluting the ions from samples of myocardium and assaying the eluate. The method yields similar results to those obtained by a previous method, in which myocardial samples were homogenized. The K:Na ratios on samples of horizontal slices through the heart were plotted on maps of the slices. A low K:Na ratio corresponded to, but extended beyond, areas where there was morphological evidence of ischaemia. The method is simple and may be of use in routine practice.