影响昆虫呼吸代谢的因素

<正> 呼吸代谢是昆虫生命特性之一,也是研究种群能量动态的基础。随着生态能量学的发展,国内外学者对此类研究逐渐重视起来。本文根据近年来国内外有关昆虫呼吸代谢研究文献,就影响昆虫呼吸代谢的因素,如温度、体重、饥饿程度和生活习性等进行讨论,旨在为进一     

鞭角华扁叶蜂幼虫期的呼吸代谢

报道了鞭角华扁叶蜂Chinolyda flagellicornis幼虫不同发育时期的耗氧量.试验表明,鞭角华扁叶蜂的耗氧量随着幼虫的生长发育而增加,在同一龄期内,耗氧量与虫体鲜重呈2次曲线相关;在不同的龄期之间,耗氧量则与虫体鲜重的0.8299次方成正比.在同一龄期内,幼虫的代谢速率呈抛物线状;在整个幼虫期随着龄期的增加而呈下降趋势.     

鞭角华扁叶峰幼虫期的呼吸代谢

报道了鞭角华扁叶蜂Chinolyda flagellicornis幼虫不同发育时期的耗氧量,试验表明,鞭角华扁叶蜂的耗氧量随着幼虫的生长发育而增加,在同一龄期内,耗氧量与虫体鲜重呈2次曲线相关;在不同的龄期之间,耗氧量则与虫体鲜重的0.8299次方成正比,在同一龄期内,幼虫的代谢速率呈抛物线状;在整个幼虫期随着龄期的增加而呈下降趋势。     

天蚕的呼吸代谢

天蚕AntheraeayamamaiGuerin是一种天蚕蛾科柞蚕属的大型野生绢丝昆虫。天蚕丝因其独特的色泽和质地,而被誉为“绿色金子”。近年来,有关天蚕的开发利用研究已引起我国蚕业界的重视,在天蚕的生物学、形态学、饲育与制种、茧丝加工等方面已有许多报道[1],而生理学方面的研究尚很薄弱。本文着重报道天蚕五龄幼虫及蛹期的呼吸代谢变化规律。l材料与方法试虫由山东省蚕业研究所沈孝行先生提供。实验室内自然温度下用麻株Q。rcusacvtiss加a鲜叶单头饲养所获之蛹。本试验于1995年6～7月进行。取五龄起蚕雌雄各1头用CYES—11型0。、CO。气…     

水生昆虫的呼吸方式

水生昆虫广泛分布于世界各地,在各种不同的水域,各种水生昆虫都有各自独特的呼吸方式.简述了水生昆虫的呼吸方式,包括体壁呼吸、气管鳃呼吸、气管呼吸、气盾呼吸和气泡呼吸等.并简要分析了各种呼吸方式的气体交换机制,进化成各种呼吸方式的原因.     

棉铃虫的呼吸代谢

棉铃虫的耗氧量随着幼虫的生长发育而增加。当发育状态基本相同时,在同一龄期内,幼虫耗氧量与虫体鲜重呈直线相关;在不同龄期之间,耗氧量则与虫体鲜重的0.97次方成正比。幼虫的代谢速率随着龄期的增加而稳定地降低。在20—35℃范围内,温度每升高10℃,幼虫的代谢速率约增加一倍。蛹期的代谢速率呈典型的“U”形曲线变化。从卵期及幼虫期到蛹期的呼吸商变动在0.75—0.96之间。     

中华鳖幼体呼吸代谢的初步研究

本文利用改装后的Ｋａｌａｂｕｋｈｏｖ－Ｓｋｖｏｒｓｔｏｖ呼吸器,同时测定了中华鳖在自由潜水状态下的空气呼吸和水呼吸摄氧量。结果表明：在正常生活状态下,中华鳖主要依靠空气呼吸摄氧;水呼吸仅占总呼吸摄氧量为２．６８％左右。呼吸摄氧率无显著昼夜变化。     

浅谈植物呼吸代谢的特点

对植物呼吸代谢在途径上的多样性,速率上的多变性及功能上的多面性３大特点及其在适应内外环境条件中的作用,进行了全面的概述。     

水生龟鳖类潜水生活的呼吸代谢

爬行类是动物进化史上首先登陆成功的脊椎动物。有关爬行类呼吸代谢的生理生态学研究对于比较动物呼吸机制及其进化具有特别重要的意义。爬行动物中有８％的种类营水生生活,潜水是这些次生性水生爬行动物生活的重要组成部分。水生龟鳖类以其极强的潜水能力而闻名,其生活...     

昆虫糖脂代谢研究进展

肥胖症和糖尿病的日趋流行已经成为世界范围内的公共健康问题,其病因主要在于体内血糖/血脂含量升高引起的能量代谢紊乱。大量的证据表明,昆虫可以作为研究人类代谢疾病的理想模型,它不仅能合成与哺乳动物同源的糖脂代谢相关激素(如胰岛素样肽和脂动激素),而且还具有进化保守的代谢信号通路(如雷帕霉素靶蛋白信号通路)及相关器官与组织(如中肠和脂肪体)。本文主要介绍了昆虫糖脂代谢的过程与调控机制,重点涉及脂肪体和绛色细胞的生理功能、胰岛素样肽/脂动激素对血糖的拮抗调节、参与营养物质代谢的胰岛素-胰岛素样生长因子信号通路以及与类固醇激素合成相关的胆固醇代谢等内容,并结合最新研究成果对黑腹果蝇Drosophila melanogaster糖脂代谢相关基因及其功能进行了总结,以期为昆虫生理学和人类代谢疾病研究提供参考。     

A simple indirect colorimetric assay for measuring mitochondrial energy metabolism based on uncoupling sensitivity

PurposeCancer cells rapidly adjust their balance between glycolytic and mitochondrial ATP production in response to changes in their microenvironment and to treatments like radiation and chemotherapy. Reliable, simple, high throughput assays that measure the levels of mitochondrial energy metabolism in cells are useful determinants of treatment effects. Mitochondrial metabolism is routinely determined by measuring the rate of oxygen consumption (OCR). We have previously shown that indirect inhibition of plasma membrane electron transport (PMET) by the mitochondrial uncoupler, FCCP, may also be a reliable measure of mitochondrial energy metabolism. Here, we aimed to validate these earlier findings by exploring the relationship between stimulation of oxygen consumption by FCCP and inhibition of PMET.MethodsWe measured PMET by reduction of the cell impermeable tetrazolium salt WST-1/PMS. We characterised the effect of different growth conditions on the extent of PMET inhibition by FCCP. Next, we compared FCCP-mediated PMET inhibition with FCCP-mediated stimulation of OCR using the Seahorse XF96e flux analyser, in a panel of cancer cell lines.ResultsWe found a strong inverse correlation between stimulation of OCR and PMET inhibition by FCCP. PMET and OCR were much more severely affected by FCCP in cells that rely on mitochondrial energy production than in cells with a more glycolytic phenotype.ConclusionIndirect inhibition of PMET by FCCP is a reliable, simple and inexpensive high throughput assay to determine the level of mitochondrial energy metabolism in cancer cells.     

A simple and inexpensive apparatus for measuring fish metabolism

A simple, noninvasive, and economical home-made respirometer has been used to determine the standard metabolism of goldfish. The apparatus has been tested on several fishes and has proved its accuracy in determining a mass effect on standard metabolism. The apparatus can be made easily by middle school, high school, and undergraduate students and can be used to introduce them to basic concepts in animal physiology and in biological statistics.     

ConA induced changes in energy metabolism of rat thymocytes

The influence of ConA on the energy metabolism of quiescent rat thymocytes was investigated by measuring the effects of inhibitors of protein synthesis, proteolysis, RNA/DNA synthesis, Na⁺K⁺-ATPase, Ca²⁺-ATPase and mitochondrial ATP synthesis on respiration. Only about 50% of the coupled oxygen consumption of quiescent thymocytes could be assigned to specific processes using two different media. Under these conditions the oxygen is mainly used to drive mitochondrial proton leak and to provide ATP for protein synthesis and cation transport, whereas oxygen consumption to provide ATP for RNA/DNA synthesis and ATP-dependent proteolysis was not measurable. The mitogen ConA produced a persistent increase in oxygen consumption by about 30% within seconds. After stimulation more than 80% of respiration could be assigned to specific processes. The major oxygen consuming processes of ConA-stimulated thymocytes are mitochondrial proton leak, protein synthesis and Na⁺K⁺-ATPase with about 20% each of total oxygen consumption, while Ca²⁺-ATPase and RNA/DNA synthesis contribute about 10% each. Quiescent thymocytes resemble resting hepatocytes in that most of the oxygen consumption remains unexplained. In constrast, the pattern of energy metabolism in stimulated thymocytes is similar to that described for Ehrlich Ascites tumour cells and splenocytes, which may also be in an activated state. Most of the oxygen consumption is accounted for, so the unexplained process(es) in unstimulated cells shut(s) off on stimulation.     

Effect of body size on the standard metabolism of horse mackerel

The routine metabolic rate R _R and standard metabolic rate R _S were measured in horse mackerel Trachurus trachurus at 13°C over weight range of 1·4–390 g. A data extraction method rather than the more commonly used method of extrapolating the swimming speed-metabolic rate curves back to zero swimming speed was developed to measure the R _S. The relation between R _R and R _S and weight was expressed as a linear regression with the log transformed data. The mean slope of the regression was 0·752 for R _S and 0·725 for R _S.     

A new chamber design for measuring community metabolism in a Michigan stream

We designed an open-ended community metabolism chamber to simultaneously measure surface and hyporheic metabolism. Our chamber design eliminated reaeration, compartmentalized metabolism, maintained ambient conditions and included hyporheic respiration. We compared results from our hyporheic chamber to results obtained from: (1) closed benthic community metabolism chambers constructed as recommended by Bott et al. (1978), and (2) whole-stream metabolism techniques as modified by Marzolf et al. (1994). Simultaneous comparisons of all three procedures were made for a 35 m riffle section of Augusta Creek, a 3rd-order Michigan stream, in July 1997 and repeated in July 1998. Simultaneous comparisons of all three procedures were also made for a 30 m sandy run section of Augusta Creek in September 1997, and repeated in September 1998. Our hyporheic chamber estimates for community respiration (CR₂₄) were similar to those obtained using the whole-stream metabolism procedure but were considerably higher than estimates obtained using the closed benthic chambers in three of the four experiments. These data suggest that our chamber design provided estimates of community metabolism which included both benthic and hyporheic respiration. The chamber incorporates several positive aspects of both closed chambers and the whole-stream method. This new method can be replicated, eliminates the need for a reaeration coefficient, ambient conditions are better approximated since it remains an open system, and it appears to provide more realistic estimates of whole-stream metabolism compared to the traditional chamber approach.     

A method for measuring oxygen consumption in isolated perfused gills

A method is described for measuring respiration in isolated perfused flounder gills experiencing pressures and flows similar to those seen in vivo . Mean oxygen consumption of 13 preparations bathed and perfused in identical saline was 5·00 ± 0·75 (s.e.) μ mol h⁻¹ g wet⁻¹, whilst that of five preparations perfused with saline but bathed in sea water (32 mg l⁻¹) was 12·06±2·39 (s.e.) μmol h⁻¹ g wet⁻¹. The oxygen consumption of the seawater bathed gills was significantly higher (P<0·05) than that in saline bathed gills. These results provide direct evidence both of the high metabolic activity of the gill under normal perfusion conditions and of the increased energy expenditure of the giil in hyperosmotic, compared to isosmotic, environments.     

A reappraisal of activity metabolism in Atlantic cod (Gadus morhua)

Atlantic cod ( Gadus morhua ) were forced to swim in a swim tunnel respirometer until fatigued; oxygen consumption rate (O₂) was measured during swimming at incremental speeds until the fish was exhausted and during recovery from exhaustion. Maximal oxygen consumption (O_2max) occurred during maximal activity as has been found for other fish species, but at odds with the current paradigm for Atlantic cod. Earlier experiments had drawn the conclusion that O_2max in Atlantic cod occurs during recovery from exhaustive exercise. We found no support for this paradigm in our experiments and we propose that the respiratory physiology of Atlantic cod is not unlike that of other fishes.     

A simple HPLC technique for accurate monitoring of mammalian cell metabolism

We have developed a simple and accurate isocratic HPLC method, without any prederivatisation, for the determination of glucose, lactate, glutamine, glutamate, pyrrolidone carboxylic acid and alanine in samples from mammalian cell cultures. The method has been successfully validated with enzyme analysis for each of the compounds. Quantification of pyrrolidone carboxylic acid makes the correction for glutamine decrease due to chemical decomposition very simple and accurate, and avoids some possibly erroneous calculations.