粘虫飞行肌中与能量代谢有关的酶活性研究

该文报道粘虫Mythimna separata (Walker ) 蛹及不同日龄成虫飞行肌中与3 种代谢途径有关的5 种酶,即3-磷酸甘油醛脱氢酶(GAPDH)、3-磷酸甘油脱氢酶(GDH)、乳酸脱氢酶(LDH)、3-羟酰辅酶A 脱氢酶(HOAD)、柠檬酸合成酶(CS)活性的变化。成虫羽化后,这5 种酶的活性大多数都高于蛹期,表明成虫飞行肌与能量代谢有关的活动比蛹期高。不同日龄成虫飞行肌的能量代谢特点为：成虫羽化后糖酵解循环的活性增加;1 日龄进行糖酵解的能力较强,2 日龄即具备较强的脂肪代谢能力,2～5日龄糖及脂肪代谢的能力基本相当,但7日龄脂肪代谢的能力较强。1～7日龄粘虫蛾飞行肌具有较高的GDH 和LDH活性,这既是粘虫蛾飞行肌能进行高度有氧代谢的重要标志,也是其具有一定无氧代谢能力的最好说明,而飞行肌中较高的CS活性则是粘虫蛾具有较强飞行能力的重要保证。对成虫GAPDH∶HOAD 活性进行分析比较的结果还显示,粘虫蛾持续飞行的能源物质既有脂类也有糖类,而不仅仅只限于脂类。     

不同日龄和吊飞过程中桔小实蝇成虫飞行肌能量代谢相关酶活性的变化

【目的】明确桔小实蝇Bactrocera dorsalis(Hendel)飞行肌对能源物质的利用。【方法】通过生化方法测定了能源物质代谢相关5种酶[3-磷酸甘油醛脱氢酶(GAPDH)、3-磷酸甘油脱氢酶(GDH)、乳酸脱氢酶(LDH)、柠檬酸合酶(CS)和3-羟酰辅酶A脱氢酶(HOAD)]活性的变化。【结果】桔小实蝇成虫中所测的5种酶活性随日龄的变化而变化,4日龄GAPDH,GDH,LDH和CS活性最高,20日龄HOAD活性最高。吊飞过程中,GAPDH,GDH和CS的活性变化基本一致,随吊飞时间的延长活性逐渐升高;LDH和HOAD的活性变化雌、雄虫完全不同。雄虫LDH活性除吊飞2 h外其他时间均高于静息状态,雌虫则始终低于静息状态;雄虫HOAD活性只有吊飞24 h低于静息状态水平,而雌虫吊飞后HOAD活性一直在静息状态水平及以下波动。【结论】桔小实蝇飞行所利用的能源物质包括糖类和脂肪,以糖类能源为主。吊飞过程中,雄虫除可以进行高速有氧代谢以外,还具备一定的无氧代谢能力,而雌虫只进行有氧代谢;雄虫能利用脂肪供给能量,雌虫则几乎不动用脂肪。研究结果为进一步阐明桔小实蝇的迁飞行为机制提供了依据。     

粘虫飞行过程中四种相关酶的活性变化

对3日龄粘虫雌蛾吊飞过程中4种相关酶3-羟酰辅酶A脱氢酶(HOAD)、3-磷酸甘油醛脱氢酶(GAPDH)、3-磷酸甘油脱氢酶(GDH)和乳酸脱氢酶(LDH)的研究结果表明,在室内条件下,粘虫在吊飞过程中其能量代谢有以下特点： 在吊飞的初始5 min,所有与糖代谢和脂肪代谢相关的酶活性都快速升高,这段时期脂肪代谢的酶活性也完全被活化,HOAD活性明显增强;但在随后的5～60 min持续吊飞期间与能量代谢有关的酶活性都有所下降,表明此时飞行活性趋于平稳。飞行中的粘虫具有极高的有氧代谢能力,也具备一定的无氧代谢能力。吊飞过程中HOAD∶GAPDH大于1,说明粘虫飞行过程中能源物质利用属于混合型,但动用脂肪比糖类要多。     

Metabolic indicators in the skeletal muscles of harbor seals (Phoca vitulina)

The goal of this study was to determine the distribution of citrate synthase (CS), beta-hydroxyacyl coenzyme A dehydrogenase (HOAD), and lactate dehydrogenase (LDH) activities and myoglobin (Mb) concentration in the locomotor muscles (epaxial muscles) and heart of harbor seals. The entire epaxial musculature, which produces most of the power for submerged swimming, was removed and weighed, and three transverse sections (cranial, middle, and caudal) were taken along the muscle bundle. Multiple samples were taken along points on a circular grid using a 6-mm biopsy. A single sample was taken from the left ventricle of the heart. Muscle groups of similar function were taken from three dogs as a control. Mean values were calculated for four roughly equal quadrants in each transverse section of the epaxial muscles. There were no significant differences among the quadrants within any of the transverse sections for the three enzymes or Mb. However, there were significant differences in the mean enzyme activities and Mb concentrations along the length of the muscle. The middle and caudal sections had significantly higher mean levels of CS, LDH, and Mb than the cranial section, which may be correlated with power production during swimming. The enzyme ratios CS/HOAD and LDH/CS exhibited no variation within transverse sections or along the length of the epaxial muscles. Relative to the dog, the epaxial muscles and heart of the harbor seal had higher HOAD levels and lower CS/HOAD, which, taken together, indicate an increased capacity for aerobic lipid metabolism during diving.     

美洲鲥胚胎及仔稚鱼的发育

对美洲鲥(Alosa sapidissima)早期生活史阶段的生长发育特征进行了观察和测量, 描述了胚胎和仔、稚鱼的生长发育特征。美洲鲥受精卵球形、无油球, 为沉性卵, 卵径2.85-3.28 mm。在水温20.3℃-21.9℃孵化条件下, 经过82h 孵化出膜, 根据其胚胎发育过程的形态特征, 胚胎发育分为受精卵、卵裂期、囊胚期、原肠胚期、神经胚期、器官形成期和出膜期7 个发育阶段。美洲鲥初孵仔鱼全长为(8.56±0.36) mm, 其卵黄囊体积为(4.57±0.77) mm3。1 日龄仔鱼脑部发育明显, 口张开, 肛门开通, 胸鳍形成。2 日龄仔鱼卵黄囊体积(0.71±0.23)mm3, 只有刚孵化的15.54%。3 日龄仔鱼经过1d 的混合营养期, 卵黄被完全吸收, 4 日龄仔鱼完全营外源性营养, 卵黄囊的体积(V)随孵化时间(h)的变化方程为V=4.1583e?0.0356h(R2=0.9901)。此后, 背鳍鳍条、尾鳍鳍条、臀鳍鳍条和腹鳍鳍条相继在晚期仔鱼出现, 9 日龄仔鱼尾椎开始弯曲, 21 日龄仔鱼尾椎弯曲完成。27 日龄鱼鳞开始形成, 到33 日龄稚鱼全身披鳞, 个体发育进入幼鱼期, 仔稚鱼期间的生长模型方程为: TL=0.0049D2+0.5091D+9.2578 (R2=0.9885, TL 为全长, D 为日龄)。       

Expression of the paternal genes for lactate dehydrogenase, glutamate dehydrogenase and acetylcholinesterase in the development of hybrid fish between species from the families of Cobitidae and Cyprinidae]

The time of expression of the paternal genes of glutamate dehydrogenase (GDH), lactate dehydrogenase (LDH) and acetylcholine esterase (AChE) was investigated in the development of fish hybrids. The species which differed by the thermostability of homologous enzymes were selected as parental pairs. The appearance of differences in the thermostability of homologous enzymes between the hybrids and the maternal species suggested the beginning of paternal enzyme synthesis in the hybrid embryos. Differences in the AChE thermostability appeared simultaneously with the enzyme activity at the stage of first muscle contractions (35 hrs of development), differences in the mitochondrial GDH thermostability appeared at the stage of hatching (50-60 hrs) and those in the LDH thermostability 12-17 days after hatching. The total activity of AChE and GDH sharply increased during the period of the paternal enzyme appearance whereas the activity of LDH suffered practically no changes. Differences in the AChE thermostability between the hybrids and the maternal species are the same for both the total AChE (in supernatant, 15,000 gX10 min.) and the solubilised AChE (in supernatant, 130,000 gX60 min.). AChE of the parental species and the hybrids have the same electrophoretic mobility. The differences in the thermostability of enzymes are preserved following the electrophoresis in polyacrilamide gel.     

cDNA cloning, tissues, embryos and larvae expression analysis of Sox10 in half-smooth tongue-sole, Cynoglossus semilaevis

A half-smooth tongue-sole, Cynoglossus semilaevis Sox10 (Accession no.: EU070763) was isolated from brain of tongue sole by using homologous cloning and RACE method. The complete cDNA of the tongue sole Sox10 contains a 35 bp 5′UTR, a 1338 bp open reading frame (ORF) encoding 445 amino acids and a 1155 bp 3′UTR. A condensed phylogenetic tree was constructed based on the amino acid sequences of tongue sole Sox10 and other well-defined vertebrate Sox. The overall topology of the tree showed the tongue sole Sox10 clusters with all Sox10. Alignment of amino acid residues of the tongue sole Sox10 gene with those from other vertebrate indicated high level conservation of amino acid sequence. The RT-PCR analysis demonstrated that the tongue sole Sox10 was highly expressed in brain, gills, skin and eyes, intermediately in spleen, heart, head–kidney and muscles, weakly expressed in kidneys and intestine and no expression in liver and gonad. The Sox10 was also expressed weakly in germ cell and zygote. We cannot detect the expression of the Sox10 in 8-cells stage. However it resumed expression weakly from blastula stage to middle of gastrula. And it expressed highly from neurula stage to 25 dah (day after hatching). It suggested that the Sox10 was involved in the development of embryos and larvae in tongue sole.     

Metabolic and molecular stress responses of gilthead seam bream Sparus aurata during exposure to low ambient temperature: an analysis of mechanisms underlying the winter syndrome

The winter syndrome in the gilthead sea bream Sparus aurata indicates that the species is exposed to critically low temperatures in Mediterranean aquaculture in winter. The present study of metabolic patterns and molecular stress responses during cold exposure was carried out to investigate this “disease”, in light of the recent concept of oxygen and capacity limited thermal tolerance. The metabolic profile of fuel oxidation was examined by determining the activities of the enzymes hexokinase (HK), aldolase (Ald), pyruvate kinase (PK), l-lactate dehydrogenase (l-LDH), citrate synthase (CS), malate dehydrogenase (MDH) and 3-hydroxyacyl CoA dehydrogenase (HOAD) in heart, red and white muscle after exposure to temperatures of 10, 14 and 18°C. Especially, the increase in LDH activity combined with the accumulation of l-lactate in tissues indicates that temperatures below 14°C are critical for Sparus aurata and stimulate the anaerobic component of metabolism. Increase in the activity of HOAD suggests that oxidation of free fatty acids might contribute to ATP turnover at low temperatures. The expression of Hsp70 and Hsp90 in all tissues examined revealed a cellular stress response during cooling below 18°C. In the light of winter temperatures in S. aurata cultures around 10°C, our data suggest that the fish are exposed to stressful conditions at the low end of their thermal tolerance window. These conditions likely impair the aerobic capacity of the fish, compromise the rates of growth and reproduction and may contribute to elicit pathological conditions.     

Ontogenetic changes in enzyme activities associated with energy production in the spiny lobster, Jasus edwardsii

The larval life of the spiny lobster Jasus edwardsii is one of the longest and most complex of any marine organism and is poorly understood due to the difficulty of studying cryptic, pelagic organisms. Hence, the capacity for active swimming in the phyllosoma, puerulus and juvenile stages and the use of possible metabolic fuel reserves was inferred from a number of enzyme activities, including citrate synthase, lactate dehydrogenase, and HOAD. High activities of CS and LDH in abdominal tissues of Stage 11 phyllosoma and pueruli are consistent with a capacity to commence active on-shore movement. The activities of LDH and HOAD showed positive allometry while CS was independent of body mass. The body mass dependence of LDH activity may reflect the developing ability of the lobster to initiate brief escape manoeuvres, and the scaling of HOAD reflects an increased use of lipid fuel reserves. Aerobic enzyme activities were higher in abdominal tissues than in cephalic tissues of pelagic pueruli, but high activities appear in the cephalic tissues of juveniles. These changes mirror a developmental shift in activity from pelagic oceanic swimming to a benthic existence on the seabed of the near shore. The low LDH activity in pueruli confirmed previous findings that they have limited feeding capacity, with carbohydrate contributing little towards the major energy reserves. The highest LDH activities occur in the abdominal muscles of juveniles and correlate with rapid tail-flicking escape behaviour. The activities of HOAD increased throughout development, and in the abdominal tissues of juveniles, may reflect lipid transformation and accumulation as an energy reserve. Enzyme activities, therefore, provide useful information concerning migratory behaviour that is presently unavailable from ecological studies.     

苯酚对多刺裸腹溞糖及蛋白质代谢酶的影响

采用急性毒性方法,研究了苯酚对多刺裸腹溞(Moina macrocopa)糖及蛋白质代谢的影响。实验设对照组和5个苯酚处理组,苯酚浓度分别为0.25、0.75、1.25、1.75、2.25 mg/L。分别在苯酚处理24 h和48 h后用分光光度法测定丙酮酸激酶(PK)、乳酸脱氢酶(LDH)、琥珀酸脱氢酶(SDH)、谷草转氨酶(GOT)和谷丙转氨酶(GPT)的活力。结果显示,随着苯酚浓度的增加和处理时间的延长,LDH活力呈现升高趋势,PK和SDH活力与对照组相比没有显著性差异。GOT活力在处理24 h后先升后降,处理48 h后活力降低;GPT活力在处理24 h、48 h后活力均升高。结论是:苯酚中毒需要高水平的代谢能量,导致裸腹溞代谢发生重大改变,诱导能量代谢一定程度上由碳水化合物分解代谢向蛋白分解代谢转变。     

Influence of green light illumination on several enzymes involved in energy metabolism in the oriental armyworm,Mythimna separata (Lepidoptera: Noctuidae)

The oriental armyworm, Mythimna separata Walker, is an important insect pest in eastern Asia. Green (520 nm) light with an exposure time of >30 min can result in a stronger phototactic response than the wavelengths of other lights in M. separata moths. The present study was mainly focused to estimate the activities of several enzymes (such as glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glycerol-3-phosphate dehydrogenase (GPDH), lactate dehydrogenase (LDH) and 3-hydroxyacyl-CoA dehydrogenase (HOAD)) involved in the energy metabolism and a ratio of HOAD to GAPDH activity in M. separata moths exposed to the green light for different exposure times. Our results showed that when M. separata moths were exposed to the green light for 30 min, the activities of the two enzymes (GPDH and HOAD) and as well as the ratio of HOAD to GAPDH activity were significantly elevated. The activity of LDH was significantly increased in the moths exposed for 60 min. Furthermore, significant differences in enzyme activities between the male and female moths were recorded in 45 min exposure time group of the GAPDH, all light treatment groups of the LDH, and 45 min group of the ratio of HOAD to GAPDH activity, respectively. We suggest that when M. separata adult moths are exposed to the green light, these enzymes can be activated to produce energy for starting the phototactic behavior to the green light. Our findings may provide a theoretical basis for elucidating a reason of the phototactic behavior of nocturnal moths.     

Digestive capacities,inbreeding and growth capacities in juvenile Arctic charr Salvelinus alpinus

Genetic variation in growth performance was estimated in 26 families from two commercial strains of Arctic charr Salvelinus alpinus. Physiological determinants of growth and metabolic capacities were also assessed through enzymatic assays. A relatedness coefficient was attributed to each family using parental genotypes at seven microsatellite loci. After 15 months of growth, faster growing families had significantly lower relatedness coefficients than slower growing families, suggesting their value as indicators of growth potential. Individual fish that exhibited higher trypsin activity also displayed higher growth rate, suggesting that superior protein digestion capacities can be highly advantageous at early stages. Capacities to use amino acids as expressed by glutamate dehydrogenase (GDH) activities were lower in the liver of fast‐growing fish (13–20%), whereas white muscle of fast‐growing fish showed higher activities than that of slow‐growing fish for amino acid metabolism and aerobic capacity [22–32% increase for citrate synthase (CS), aspartate aminotransferase (AAT) and GDH]. The generally higher glycolytic capacities (PK and LDH) in white muscle of fast‐growing fish indicated higher burst swimming capacities and hence better access to food.     

Modifications in energy metabolism during the development of chick glial cells and neurons in culture

Developmental changes in lactate dehydrogenase (LDH), enolase, hexokinase (HK), malate dehydrogenase (MDH), and glutamate dehydrogenase (GDH) activities were measured in cultures of pure neurons and glial cells prepared from brains of chick embryos (8 day-old for neurons, 14 day-old for glial cells) as a function of cellular development with time in culture. The modifications observed in culture were compared to those measured in brain extracts during the development of the nervous tissue in the chick embryo and during the post-hatching period. A significant increase of MDH, GDH, LDH, and enolase activities are observed in neurons between 3 and 6 days of culture, whereas simultaneously a decrease of HK values occurs. In the embryonic brain between 11 and 14 days of incubation, which would correspond for the neuronal cultures to day 3 through 6, modifications of MDH, GDH, HK, and enolase levels are similar to those observed in neurons in culture. Only the increase of LDH activity is less pronounced in vivo than in cultivated cells. The evolution of the tested enzymatic activities in the brain of the chick during the period between 7 days before and 10 days after hatching is quite similar to that observed in cultivated glial cells (prepared from 14 day-old embryos) between 6 and 18 days of culture. All tested activities increased in comparable proportions. The modifications of the enzymatic profile indicate that some maturation phenomena affecting energy metabolism of neuronal and glial elements in culture, are quite similar to those occuring in the total nervous tissue. A relationship between the development of the energy metabolism of the brain and differentiation processes affecting neuroblasts and the glial-forming cells is discussed.     

社群等级对金乌贼行为表型及能量代谢的影响

采用实验生态学方法,在室内水槽条件下研究了金乌贼(Sepia esculenta Hoyle,1885)繁殖过程中社群等级的形成对其行为表型和能量代谢的影响,分析测定了不同优势等级雌雄个体腕部肌肉和性腺组织中己糖激酶(Hexokinase, HK)、丙酮酸激酶(Pyruvate kinase, PK)、乳酸脱氢酶(Lactate dehydrogenase, LDH)、苹果酸脱氢酶(Malate dehydrogenase, MDH)、柠檬酸合酶(Citrate synthetase, CS)活性以及乳酸(Lactic acid, LD)含量。结果显示:(1)金乌贼繁殖期不同优势等级雌雄个体之间行为表型具有显著差异,优势雄性个体游动悬浮、争斗时间显著高于劣势个体,而优势雌性个体静止伏底时间高于劣势个体,游动悬浮时间低于劣势雌性;(2)优势雄性个体在争斗过程中主要通过无氧代谢提供能量,而处于游动悬浮状态时通过有氧代谢提供能量。主要表现在优势雄性个体肌肉中无氧代谢酶(PK、HK、LDH)活性显著高于劣势个体(P<0.05),有氧代谢酶(MDH、CS)活性也显著高于劣势个体,雌性个体之...     

Relation between growth rate and metabolic organization of white muscle,liver and digestive tract in cod,Gadus morhua

To determine whether the aerobic capacity of tissues required for growth specifically reflects growth rates, we monitored the activities of key enzymes of oxidative, glycolytic and amino acid metabolism in muscle, liver and intestine of Atlantic cod (Gadus morhua) growing at different rates. Fish were maintained individually in small tanks at 10°C and fed on rations that allowed growth rates ranging from-0.6 to 1.6% per day. The correlation between growth rate and muscle enzyme activity was pronounced for the glycolytic enzymes (LDH, PFK and PK). The activities of glycolytic enzymes were more than four times higher for fish having higher growth rates compared to those that did not grow. Mitochondrial enzyme (cytochrome c oxidase, citrate synthase and -hydroxyacyl-CoA dehydrogenase) activities remained unchanged in fish with positive growth. The liver seems to respond to requirements of growth by an increase in size. In the liver, the activities of the enzymes of amino acid metabolism expressed as units · g DNA^-1 specifically increases with growth rate. In contrast to the two other tissues, the specific activities of mitochondrial enzymes in the intestine increased with growth rate while the relative mass of the intestine remained constant. Intestinal cytochrome c oxidase activity increased from a minimum of about 2 to more than 8 units · g intestine^-1. Cytochrome c oxidase activity increased in parallel with the food conversion efficiency. This suggests that the aerobic capacity of the intestine may initially limit the rates of digestion and growth in this species.Abbreviations AA amino acid(s) - BM body mass - CCO cytochrome c oxydase - CS citrate synthase - DTNB 5,5 dithiobis-2-nitrobenzoic acid - GDH glutamate dehydrogenase - GOT glutamate oxalacetate transaminase - GPT glutamate pyruvate transaminase - GR growth rate(s) - HOAD -hydroxyacyl-CoA dehydrogenase - HSI hepatosomatic index - LDH lactate dehydrogenase - MR metabolic rate(s) - PCA perchloric acid - PFK phosphofructokinase - PK pyruvate kinase - PMSF phenylmethylsulphonyl fluoride; TRIS     

Energy metabolism in eggs and larvae of the Senegal sole

Oxygen consumption in Solea senegalensis increased during the egg stage reaching values close to 4 nmol O₂ ind⁻¹ at hatching. After hatching, larval oxygen consumption continued to increase, reaching a maximum rate of 9.97⁻¹±87 nmol O₂ ind⁻¹ h⁻¹ 2 days after the opening of the mouth. Body nitrogen content decreased mainly after exhaustion of yolk reserves. Carbon content decreased during the whole endogenous feeding phase, although it decreased twice as quickly after yolk-sac absorption. The free amino acid (FAA) depletion rate was higher during egg development and the yolk-sac period. Complete yolk absorption coincided with the consumption of the 90% of initial FAA content in the eggs and the remaining FAA were consumed at a lower rate. Based on stoichiometrical calculations, FAA appears to be the most important energy substrate during the egg stage (86%) in the Senegal sole. During the period from hatching to the mouth opening, contributions of FAA and lipids as metabolic fuels were similar (41 and 47%, respectively). The decrease in larval protein content during starvation indicates that amino acids from body protein are used as energy substrates under food deprivation.     

Development of the activities of oxidative, glycolytic and muscle enzymes during early larval life in three families of freshwater fish

The development of the activities of oxidative (COX, CS), glycolytic (PFK, PK, LDH) and muscle enzymes (CK, MK, Pase) was studied in representatives of the families Coregonidae, Salmonidae and Cyprinidae, from hatching to an age of approximately 100 days. In addition, the activities of two enzymes of amino acid metabolism (GOT, GPT) were followed in rainbow trout and in roach.
Water content of fresh body weight and protein content of dry body weight decrease during the early larval period. Specific activities of the two oxidative enzymes decline, whereas those of glycolytic and muscle enzymes increase in all species.
A family-specific event is the enormous increase in glycolytic and muscle enzymes from very low values in the early larva to very high levels in adult Coregonus sp. In rainbow trout, CS activity begins with a low-level period lasting throughout the yolk-sac period, whereas in the other species CS activity is high immediately after hatching.
Acclimation to either 15 or 20° C has no effect on the mass-specific activities of PFK, M K, CK and Pase in roach and chub, but the former three enzymes appear to be strongly dependent on rearing conditions during the early larval period, whereas Pase is not.     

Hepatotoxic effects of CCl4 on English sole (Parophrys vetulus): possible indicators of liver dysfunction

Selected serum parameters (enzyme activities and triglycerides) and liver glutathione and vitamin C concentrations were measured in English sole (Parophrys vetulus) after i.p. injection of carbon tetrachloride (CCl4), a hepatotoxin in fish. Serum lactate dehydrogenase (LDH), alkaline phosphatase (AP) and glutamate dehydrogenase (GDH) activities and the concentration of triglycerides increased in a dose-dependent manner 24 hr post injection. Concentrations of glutathione (reduced and oxidized) and ascorbic acid (vitamin C) in liver did not change in response to CCl4 toxicity 24 hr post injection. These studies indicate that serum AP activity and triglyceride concentrations can be useful in assessing the effects of CCl4-induced liver toxicity in this species of marine fish. Serum LDH and GDH activity should be used with some caution in assessing liver damage in English sole, as other tissues represent more likely sources for serum activity. The levels of liver antioxidants do not appear to be significantly affected, 24 hr post injection, by this particular hepatotoxin.     

Zum Energiestoffwechsel des Gehirns

Zusammenfassung In Gehirnen von Karauschen, Fröschen, Eidechsen, Webervögeln und Mäusen wurden die Aktivitäten von GAPDH, LDH, GDH, GPox, G-6-PDH, CS, SDH und HOAD bestimmt. In allen Fällen zeigen LDH und GAPDH sowohl die bei weitem höchsten Werte als auch weitgehende Übereinstimmung. G-6-PDH ist mit Ausnahme des Froschhirns überall nur in sehr geringer Aktivität vorhanden, während für HOAD stets verhältnismäßig höhere Aktivitäten gemessen wurden. Die Enzyme von Citrat- und GP-Cyclus zeigen in ihrem Verhältnis zur GAPDH eine deutliche Zunahme von den Fischen zu Vögeln und Säugern.Aus diesen Befunden wird geschlossen, daß eine überwiegende Einstellung auf Kohlenhydratabbau als allgemeines Merkmal des Energiestoffwechsels im Vertebratenhirn gelten kann. Die höheren Wirbeltiere zeigen die Tendenz zur Steigerung der Kapazität zur aeroben Oxidation.

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Energy metabolism of the brainA comparative investigation on representatives of the different vertebrate classes

Summary The activities of GAPDH, LDH, GDH, GPox, G-6-PDH, CS, SDH, and HOAD were assayed in the brains of fish (Carassius), frog (Rana), lizzard (Lacerta), birds (Euplectes, Estrilda) and mouse (Mus). LDH and GAPDH had by far the highest activities and were found to have similar activities in all brains. G-6-PDH activities were very low except in frog-brain. HOAD showed a distinctly higher activity. The enzymes involved in the citric acid and glycerophosphate cycles were relatively increased in higher vertebrates compared with the lower ones.It is concluded from these findings, that the preponderance of carbohydrates as an energy source is a characteristic quality of brain metabolism in all vertebrates, although in the higher classes there appears to be a tendency to increase the capacity of aerobic oxidation.

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Herrn Dr. H.W. Hagens () gewidmet.

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Diese Untersuchung wurde von der Deutschen Forschungsgemeinschaft durch ein Stipendium (G.W.) unterstützt.     

Lactic and alpha-glycerophosphate dehydrogenases in insects

Different tissues, especially muscles, from insects belonging to various groups were extracted and studied for their lactic dehydrogenase (LDH) and α-glycerophosphate dehydrogenase (GDH I) activities from the comparative point of view. In all cases assays of flight muscle extracts showed extremely low values of LDH activity whereas the GDH activities were surprisingly high. The activities in leg muscles were generally lower. In some insects, however, a very active LDH was found; in these cases the GDH activity seemed to be decreased. GDH I was rather active in the fat bodies. The presence of particulate glycerophosphate dehydrogenase (GDH II) was also demonstrated in insect muscles. These results were interpreted as indicating a system by which there is accomplished immediate and direct breakdown of metabolites to supply large amounts of energy during flight and other activities without the accumulation of intermediate substances.