~(13)碳核磁共振波谱学检测烧伤大鼠肝脏细胞合成功能的变化

目的　建立安全、特异的13 碳核磁共振 ( 13 CNMR)波谱学方法 ,观察严重烧伤大鼠肝脏细胞糖原异生和回补反应等合成代谢功能的变化。　方法　成年SD大鼠在吸入麻醉下行左颈动脉和右颈外静脉插管后 ,随机分成 40 %TBSAⅢ度烫伤组 (B组 )和假烫伤对照组 (C组 )。B组伤后 2 0min开始液体复苏 ,伤后 72h静脉持续滴注示踪剂 [1、2、3- 13 C]-丙酸钠 (SP) ,并于滴注 45和 6 0min时分别检测血浆和肝脏13 CNMR波谱、动脉血压、心率、血糖和血钠水平 ,运用输入 -输出三羧酸循环的数学模型计算代谢参数。　结果　烧伤后 72hB组动脉血压仍低于C组 ,血糖与C组比较无明显差异 ;SP对平均动脉压、心率和血钠均无影响 ;血糖13 C同位素标记形式与肝糖一致 ;持续滴注SP 45min时SP即可达到代谢稳定状态 ;B组肝脏细胞糖原异生、回补反应和丙酮酸循环的碳流量均较C组明显增强 ,而三羧酸循环碳流量相对减少 ;肝脏丙氨酸、谷氨酸和谷氨酰胺池也明显扩大。　结论　静脉注射SP不改变平均动脉压、心率和血钠 ,静脉滴注示踪剂 45min即能达到代谢稳态 ,血糖13 C标记形式可代表肝糖的13 C标记形式 ;大面积烧伤后 72h ,肝脏回补反应、糖原异生和丙酮酸循环均增强 ,但外周组织血糖的利用率也相应提高     

严重烧伤后早期大鼠肝脏细胞内外钠离子分布和化学状态的变化

目的观察大鼠严重烧伤后肝脏细胞内、外Na 在分布和化学状态上的改变,为烧伤后早期液体复苏方案的选择提供理论指导。方法选取成年雄性SD大鼠19只,随机分为对照组(12只)、烧伤组(7只),采用钠-23磁共振(23NaNMR)波谱技术和位移试剂,测定两组大鼠肝脏细胞内、外Na 的纵向弛豫时间(T1)和横向弛豫时间(T2)的变化。结果输注位移试剂后,烧伤组大鼠肝脏细胞外Na 浓度降低17%,其快T2所占百分比较对照组有所增加(P<0.01),提示细胞外可与Na 结合或可影响Na 的位点增加;细胞内Na 浓度升高了59%,但其弛豫行为却未发生变化。结论烧伤后早期细胞外的Na 可因向细胞内流失或受其周围大分子可逆性结合位点的影响,使瞬时可发挥渗透粒子作用的Na 相对不足,提示烧伤后第1个24h选择适量高钠溶液复苏较合理。     

Diffusion of small solutes in cartilage as measured by nuclear magnetic resonance (NMR) spectroscopy and imaging

The ability of water and solutes to move through the cartilage matrix is important to the normal function of cartilage and is presumed to be altered in degenerative diseases of cartilage such as osteoarthritis and rheumatoid arthritis. Nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) techniques were used to measure a self diffusion coefficient (D) for small solutes in samples of explanted cartilage for diffusion times ranging from 13 ms to 2s. With a diffusion time of 13 ms, the intratissue diffusivity of several small solutes (water, Na⁺, Li⁺, and CF₃CO₂^?) was found consistently to be about 60% of the diffusivity of the same species in free solution. Equilibration of the samples at low pH (which titrates the charge groups so that the net matrix charge of ?300 mM at pH 8 becomes approximately ?50 mM at pH 2) did not affect the diffusivity of water or Na⁺. These data, and the similarity between the D in cartilage relative to free solution for water, anions, and cations, are consistent with the view that charge is not an important determinant of the intratissue diffusivity of small solutes in cartilage. With 35% compression, the diffusivity of water and Li⁺ dropped by 19 and 39%, respectively. In contrast, the diffusivity of water increased by 20% after treatment with trypsin (to remove the proteoglycans and noncollagenous proteins). These data and the lack of an effect of charge on diffusivity are consistent with D being dependent on the composition and density of the solid tissue matrix. A series of diffusion-weighted proton images demonstrated that D could be measured on a localized basis and that changes in D associated with an enzymatically depleted matrix could be clearly observed. Finally, evidence of restriction to diffusion within the tissue was found with studies in which D was measured as a function of diffusion time. The measured D for water in cartilage decreased with diffusion times ranging from 25 ms to 2 s, at which point the measured D was roughly 40% of the diffusivity in free solution. Although changes in matrix density by compression or digestion with trypsin led to a decrease or increase, respectively, in the measured D, the functional change in measured diffusivity with diffusion time remained essentially unchanged. In a different type of study, in which bulk transport could be observed over long periods of time, cartilage was submerged in 99% D₂O and MRI studies were performed to demonstrate the bulk movement of water out of the cartilage matrix. These studies yielded a diffusivity estimated to be approximately 40% of the diffusivity of water in solution, which is in agreement with the value obtained for the diffusivity at a diffusion time of 2 s. These NMR measurements of diffusion can be totally noninvasive; thus, the results reported here can be extended to in vivo situations.     

锌—金属硫蛋白对大鼠皮肤烫伤创面的影响

目的 研究Wistar大鼠深Ⅱ度烧伤后皮肤活力的下降与脂质过氧化反应的关系。方法 以氧耗量、琥珀酸脱氢酶、Schiff’s碱及创面愈合时间为指标,以金属硫蛋白作为保护剂外用于烫伤创面,分别采用空白对照及5×10^-6mol/L,1×10^-5mol/L两种浓度,测定伤后8,24,48h各项指标的变化。结果 皮肤氧耗量、琥珀酸脱氢酶活性下降,Schiffs碱含量明显升高。应用金属硫蛋白保护后,皮肤活性（氧耗及琥珀酸脱氢酶含量）均显著高于对照组（P＜0．05或P＜0．01）,同时Schiff’s碱含量下降（P＜0．05或P＜0．01）,创面愈合时间平均提前2天。结论 烫伤组织损伤与脂质过氧化反应有一定的关系,而金属硫蛋白有一定保护作用。     

大鼠皮肤降钙素基因相关肽正常分布及烫伤后改变规律

目的 探讨皮肤创面降钙素基因相关肽（ＣＧＲＰ）的来源。方法 运用免疫组化技术检测烫伤后早期大鼠皮肤烫伤创面,创周及远处未损伤皮肤内含ＣＧＲＰ的神经分布密度改变。结果 烫伤后１５ｍｉｎ在以上所有部位的含ＣＧＲＰ神经纤维分布密度明显下降,烫伤后６至１２ｈ达到最低值,而后逐渐恢复,相比之下,在创周恢复过程出现较早;此外,在创面和创周的真皮层ＣＧＲＰ免疫反应阳性的巨噬细胞样大细胞从局部血管中游出,烫伤后１     

Effect of sho-saiko-to (xiao-chai-hu-tang) on hepatic injury induced by halothane in rats]

The etiology of halothane induced hepatitis is unknown. This study investigated effect of oral administration of Sho-saiko-to on hepatic injury induced by exposure to 1.1% halothane under hypoxic condition (FIO2 = 0.12) for 2 hr in rats. Serum transaminase, histological score and area of necrosis were examined in rats treated with Sho-saiko-to (900 mg.kg-1) before and after halothane exposure. Twenty-four hours following halothane exposure, serum transaminase levels were significantly depressed; the level of sGOT was significantly lower in rats with treatment of Sho-saiko-to (211 +/- 34 IU.l-1) than in rats without treatment (264 +/- 42 IU.l-1) (P less than 0.05), and the level of sGPT was significantly lower in rats with treatment of Sho-saiko-to (144 +/- 20 IU.l-1) than in rats without treatment (215 +/- 46 IU.l-1) (P less than 0.01). Histological score in rats treated with Sho-saiko-to was significantly lower (3.8 +/- 0.6) than in rats without treatment (4.5 +/- 0.7) (P less than 0.05). The area of centrilobular necrosis was significantly lower in rats with treatment of Sho-saiko-to (21.2 +/- 8.7%) than in rats without treatment (34.5 +/- 12.7%) (P less than 0.05), too. These results indicate that Sho-saiko-to inhibits the hepatic necrosis and functional disorder following exposure to halothane.     

Alterations of gluconeogenesis by ischemic renal injury in rats]

This study was designed to determine changes in one of metabolic functions, gluconeogenesis after ischemic renal injury. Right kidneys of SD rats were removed and a vascular clamp was placed across the left renal artery and vein for 0, 10, 30, 60 and 90 min. On 1, 3 and 7 days after the treatment, tubule suspensions were prepared by collagenase treatment of left kidneys and incubated with or without 2 mM pyruvate or malate aerobically. After the incubation, glucose contents were assayed photometrically. Serum creatinine was also determined. In addition, morphological changes were observed under light microscopy to examine the relationship between metabolism and morphology. The tendency of increase of gluconeogenesis was observed on day 1 and 3 after 10, 30, 60 min of ischemic time. On the other hand, gluco-neogenesis decreased significantly on day 1 after 90 min treatment. In contrast, on day 1 and 3 after treatment, serum creatinine levels showed no difference from control at the groups of 10 and 30 min ischemia. Whereas it rose significantly at the group of 60 min ischemia, showing a different tendency from that of the increase of gluconeogenesis. Moreover, morphologic damage was observed on day 1 and 3 after ischemia of 30 and 60 min. The morphologic damage was found more advanced in the corticomedullary region than those of the cortex which has the high gluconeogenic activity and which thus showed relatively limited damage. These results suggest that renal gluconeogenesis is relatively insusceptible to ischemic injury.(ABSTRACT TRUNCATED AT 250 WORDS)     

早期手术对烧伤大鼠肝血流量的影响

目的通过测定 TBSA30％Ⅲ度烧伤大鼠早期手术后肝血流量的变化,了解早期手术对肝脏血液灌流的影响。方法 Wistar 雄性大鼠34只,分为4组:烧伤组(A 组),输液组(B 组),早期手术组(C 组),正常对照组(D 组)。输液组经股静脉插管输入乳酸林格氏液;早期手术组于立即补液的同时行切痂同种异体植皮术。各组于伤后0,0.5,1,2,3,6,12和24小时,应用氢清除法测定肝血流量。结果 A 组与 B 组伤后均出现肝血流量显著下降,B 组直至伤后24小时肝血流量才恢复正常,而 C 组伤后肝血流量保持相对稳定,与正常对照组比较无显著意义。结论严重烧伤后立即液体复苏尚不足以维持有效的肝脏血流灌流,烧伤后早期手术尽早地去除焦痂组织,对改善肝血流量具有重要作用。     

早期手术对烧伤大鼠肝血流量的影响

目的通过测定ＴＢＳＡ３０％Ⅲ度烧伤大鼠早期手术后肝血流量的变化，了解早期手术对肝脏血液灌流的影响。方法Ｗｉｓｔａｒ雄性大鼠３４只，分为４组：烧伤组（Ａ组），输液组（Ｂ组），早期手术组（Ｃ组），正常对照组（Ｄ组）。输液组经股静脉插管输入乳酸林格氏液；早期手术组于立即补液的同时行切痂同种异体植皮术。各组于伤后０，０．５，１，２，３，６，１２和２４小时，应用氢清除法测定肝血流量。结果Ａ组与Ｂ组伤后均出现肝血流量显著下降，Ｂ组直至伤后２４小时肝血流量才恢复正常，而Ｃ组伤后肝血流量保持相对稳定，与正常对照组比较无显著意义。结论严重烧伤后立即液体复苏尚不足以维持有效的肝脏血流灌流，烧伤后早期手术尽早地去除焦痂组织，对改善肝血流量具有重要作用     

Alterations in thyrotropin (TSH) binding in iodine-deficient rats

Thyrotropin (TSH) is thought to stimulate thyroid activity and growth by binding to TSH receptors on thyroid plasma membranes. Iodine depletion has been shown to increase the sensitivity of the thyroid to the goitrogenic effects of TSH. The present investigation was performed to determine if chronic iodine depletion altered either the number or the affinity of TSH receptor sites in the thyroid. Six paired experiments were performed comparing the binding of ¹²⁵I-labeled bovine TSH to a particulate fraction of thyroid from male Sprague-Dawley rats that had received regular (C) or low iodine diet (LID) for 3 to 7 months. The number of TSH receptors and the association constants of these receptors were calculated from Scatchard plots and binding was compared with glandular concentrations of DNA, RNA, protein, plasma membrane markers (5′-nucleotidase, Mg²⁺ ATPase, Na⁺, K⁺ ATPase), and per thyroid gland. (1) The weights of all animals were initially similar but after 3 to 7 months the LID group (638 ± 139 g (mean ± 1 SD)) was heavier than the C group (544 ± 45 g (P < .01)). (2) Serum TSH concentrations in the LID group (5231 ± 547 ng/ml) were higher than those in the C group (850 ± 221 ng/ml) (P < .005). (3) Thyroid weight, thyroid weight per animal weight, DNA, RNA, total protein, Mg²⁺ ATPase, Na⁺, K⁺ ATPase, and 5′-nucleotidase were all increased in the LID group (P < .005). Histological examination demonstrated that the thyroid enlargement was primarily due to an increase in number of follicle cells, or hyperplasia. (4) The concentration of TSH receptors (maximum binding capacity) per DNA content was similar in the C and LID groups. (5) The concentration of TSH receptors per plasma membrane marker decreased in the LID group (P < .01) primarily because of the large increase in amount of plasma membrane. (6) The total number of TSH receptors per thyroid gland or TSH receptor content increased from 0.52 ± 0.16 × 10¹⁴ in the C group to 2.27 ± 0.79 × 10¹⁴ in the iodine-deficient animals (P < .001), and the association constant in these animals (1.28 ± .27 × 10⁸M^?1) was also higher than that in the C group (0.68 ± 0.16 × 10⁸M^?1) (P < .001). Thus, chronically iodine-deficient rats developed increased serum TSH concentrations and enlarged hyperplastic thyroid glands. Although the number of TSH receptors per DNA or cell did not change in the respective groups, the TSH receptor content and the association constant of these receptors for TSH in the thyroid gland of the iodine-deficient animals increased. It therefore appears that increased serum TSH concentrations in iodine-deficient rats exerts a positive regulatory effect on its own receptors and that alterations in serum TSH level modulate the TSH receptor. Whether this effect is due to a direct effect of TSH on the TSH receptor or an indirect effect secondary to thyroid growth is unknown.     

大鼠烫伤后肾上腺内含降素基因相关肽神经的改变

目的 探讨皮肤烫伤早期大鼠肾上腺内降钙素基因相关肽（CGRP）变化规律,为阐明烫伤后肾上腺内分泌功能改变的机理提供资料。方法 采用15％深Ⅱ度大鼠烫伤模型,以免疫组化方法分别检测烫伤后不同时相点肾上肾皮质、髓质CGRP免疫反应阳性神经和细胞分布密度的改变。结果 ①在肾上腺被膜,皮质,髓质均有含CGRP神经分布,其中髓质更为密集。在髓质可见含CGRP神经与CGRP免疫反应阳性细胞密切接触;②烫伤早期大鼠肾上腺皮质和髓质含CGRP神经的分布密度均下降,但髓质内CGRP免疫反应阳性细胞的分布密度上升。结论 降钙素基因相关肽可能是烫伤大鼠肾上腺功能改变的影响因素之一。