Widespread alterations in central noradrenaline,dopamine, and serotonin systems in the Brattleboro rat not related to the local absence of vasopressin

A comprehensive study of monoamine transmitter and metabolite concentrations measured by HPLC was undertaken in female (vasopressin-deficient) Brattleboro rats as compared to Long Evans rats. Noradrenaline was significantly increased in 8 out of 13 dissected brain regions, whereas concentrations of the metabolite 3-methoxy-4-hydroxyphenylglycol were not altered. The increases were not restricted to areas which are normally innervated by vasopressin-containing neurons. Serotonin was increased in 6 and dopamine in 4 regions and this was accompanied in some areas by increases in the metabolites 5-hydroxyindolacetic acid and dihydroxyphenylacetic acid. Only in the striatum, cerebellum, and the medulla-pons no changes could be detected in any of the compounds of interest. These results show that the long term absence of vasopressin in Brattleboro rats appears to be associated with increases in monoamine transmitter contents and decreased metabolite/transmitter ratios. The regional distribution of these changes does not bear any relationship to the regional distribution of vasopressin cell bodies or nerve endings.     

The effect of chromium on parameters related to iron metabolism

The effect of chromium on some parameters related to iron metabolism was investigated. Preliminary experiments showed that this metal ion was taken up by serum proteins and was dependent on the amount of chromium present in the medium. It was also shown that the uptake of iron was reduced significantly in the presence of chromium. In vivo study showed that the serum levels of iron and total iron binding capacity (TIBC) were reduced by 28 and 11%, respectively, following daily administration of chromium (1 mg/kg) for 45 d. Serum ferritin was reduced by 22% under this condition. Hematocrit and hemoglobin levels were also affected in chromium-treated animals and were both reduced by 17%. Spectrophotometric titration of each individual amino acid located in the iron binding site of transferrin revealed that tyrosin might be the most suitable ligand for the binding of chromium to transferrin. These results suggest that chromium may compete with iron in binding to apo-transferrin, and influence iron metabolism and its related biochemical parameters.     

Responses of morphological, physiological, and biochemical parameters in Euglena gracilis to 7-days exposure to two commonly used fertilizers DAP and urea

Diammonium phosphate (DAP) and urea are commonly used fertilizers throughout the world. The effects of these fertilizers on the freshwater flagellate Euglena gracilis was studied after 7 days of growth using morphological, physiological and biochemical parameters as end points. NOEC and EC₅₀ values for various parameters like cell density, motility, velocity, cell shape, gravitaxis, chlorophyll a, b and total carotenoids were calculated. NOEC and EC₅₀ values of DAP varied from 0.5 to 2.5 g L⁻¹ and 3.14 to 5.96 g L⁻¹, respectively, for different parameters. NOEC and EC₅₀ values for urea ranged from 5 to 25 g L⁻¹ and 28 to 44.05 g L⁻¹, respectively, for various parameters. Photosynthetic pigments were found to be more sensitive to both fertilizers as compared to other measured end points. The NOEC and EC₅₀ values obtained for DAP were much lower than those for urea; i.e., DAP showed a stronger inhibitory effect as compared to urea. Application of DAP resulted in an increased concentration of ammonia in Euglena cultures but urea did not. The stronger inhibitory effect of DAP is attributed to release of free ammonia in the culture due to DAP decompostion. No release of ammonia by urea occurred due to the absence of the enzyme urease in E. gracilis.     

Nutritional suitability of some uni-algal diets for freshwater calanoids: unexpected inadequacies of commonly used edible greens and others

• 1 Naupliar and copepodid development times (Dn and Dc, respectively) of two African freshwater calanoids (Metadiaptomus meridianus and Tropodiaptomus spectabilis) were measured on mono-specific diets of comparably sized Chlamydomonas reinhardii, Scenedesmus acutus, Cryptomonas sp., Rhodomonas minuta, Cyclotella meneghiniana, and Selenastrum capricornutum, to test the nutritional adequacy of these algae. Comparisons were made at a standard temperature (17°C) and food supply level (1 mgCl^?1).
• 2 All diets other than Scenedesmus and Selenastrum supported complete naupliar development at broadly comparable times within and between calanoids, apart from greatly protracted Dn values for M. meridianus on Cyclotella. Dc durations were more variable between diet types, and both Chlamydomonas and Cyclotella were inferior or inadequate for copepodid development.
• 3 Both naupliar and copepodid stages ingested radiolabelled Scenedesmus and Selenastrum readily. Comparative incorporation rate measures of Selenastrum and Cryptomonas respectively exceeded estimated metabolic maintenance needs of stage 3/4 nauplii of T. spectabilis by some 56% and 790%. Scope for growth (‘surplus’ energy) was accordingly fourteen-fold greater on Cryptomonas than on Selenastrum /Scenedesmus. The dietary inadequacy of these two green algae is thus attributed largely to low digestibility, and perhaps some biochemical deficiency.

     

Effect on the plasma renin-aldosterone system of lesions to suprachiasmatic nuclei and central serotonin depletion in rats

Renin activity, angiotensin-converting enzyme activity and aldosterone concentration were measured in the plasma of 8 experimental groups of rats: I--sham operated non-treated rats, II--suprachiasmatic nuclei (SCN) lesioned non-treated: III--sham operated + furosemide (4 mg/kg i.p.), IV--SCN lesioned + furosemide, V--shams + 24-hour water deprivation: VI--SCN + 24-hour water deprivation, VII--intact rats + saline: and VIII--intact rats + p-chlorophenylalanine (pCPA, 300 mg/kg, i.p.). No significant changes in basal levels of the three parameters were found after SCN, lesions in comparison with sham operated controls. Furosemide caused a similar increase in all three parameters of both sham and SCN lesioned rats. Similar changes were observed in SCN rats 24 hours after water deprivation and in intact rats 48 hours after serotonin depletion by pCPA: suppressed renin activity together with increased aldosterone concentration. It is concluded that the central serotonergic system and SCN play a similar role in control of the renin-aldosterone system in rats under conditions of negative water-salt balance.     

强度不同的间歇跑台训练对生长期大鼠骨代谢及相关激素的影响

目的:探讨强度不同的间歇跑台训练对生长期大鼠骨代谢的影响,以期为青少年训练强度的制定提供理论支持。方法:选取4周龄雄性wistar大鼠70只,根据体重随机搭配分成7组(n=10):即对照组和运动组。运动组按照大鼠摄氧量分为:65%组,70%组,75%组,80%组,85%组和90%组。跑台训练9周,每周训练6 d,每组训练分3次,每次不低于10 min,中间间隔30 min。最后一次运动后24 h,取股骨和血进行骨密度(BMD)、骨量(BMC)和血清中的碱性磷酸酶(AKP),抗酒石酸酸性磷酸酶(Str-ACP)的测定。结果:①70%组股骨的BMD(0.1393±0.0031)、BMC(0.4525±0.0335)显著高于对照组(BMD:0.1200±0.0095,BMC:0.3238±0.0485)和其他各运动组(65%组BMD:0.1339±0.0062、BMC:0.4058±0.0492,75%组BMD:0.1296±0.0015、BMC:0.3869±0.0254,80%组BMD:0.1223±0.0082、BMC:0.3454±0.0483,85%组BMD:0.1250±0.0044、BMC:0.3731±0.0381,90%组BMD:0.1171±0.0047、BMC:0.3051±0.0286)(P<0.05),90%组的BMD、BMC低于对照组但未达到显著水平,其他各运动组均高于对照组;②各运动组血清AKP均显著高于对照组,其中65%组(41.015±2.114)、70%组(46.035±2.611)、75%组(43.834±3.155)、80%组(38.043±4.073)血清AKP非常显著高于对照组(26.875±1.188)(P<0.01),70%组和75%组血清AKP显著高于80%组、85%组、90%组(P<0.05),同时70%组血清AKP显著高于65%组(P<0.05),这说明70%VO2max的训练强度成骨细胞最活跃。各运动组血清StrACP均显著高于对照组,随着训练强度的增加,血清StrACP水平呈上升趋势,80%组(22.430±1.591)、85%组(23.990±1.870)、90%组(28.009±1.839)血清StrACP显著高于65%组(18.503±2.429)、70%组(16.447±2.120)和75%组(17.769±1.642)(P<0.05),90%组血清StrACP均显著高于80%组和85%组(P<0.05)。结论:70%VO2max的中等强度间歇跑台训练使生长期大鼠骨量、骨密度增加最明显。     

Attenuation of morphine dependence and withdrawal in rats by venlafaxine, a serotonin and noradrenaline reuptake inhibitor.

The effects of venlafaxine, a novel serotonin and adrenaline reuptake inhibitor, on the morphine withdrawal and activation of morphine conditioned place preference (CPP), were investigated in rats. Our results showed that the most morphine withdrawal signs, including jumping, writhing, shakes, exploring, lacrimation, piloerection, irritability, and diarrhea, were attenuated by pretreatment with 10 or 20 mg/kg venlafaxine. To investigate the effects of venlafaxine on relapse to opiate dependence, the morphine CPP was used and a dopamine D2 antagonist sulpiride was selected as a control drug. The morphine CPP disappeared following a 28-day drug-free period and appeared again after given a single injection of 1 mg/kg morphine. Acute treatment with sulpiride (25 or 50 mg/kg, i.p.) 30 min prior to 1 mg/kg morphine injection significantly blocked the reacquisition of CPP, while venlafaxine (10 or 20 mg/kg, i.p.) did not show significant effect. However, chronic treatment with venlafaxine (5 or 10 mg/kg, i.p. twice, daily, for seven consecutive days) significantly attenuated the reacquisition of morphine CPP, whereas chronic treatment with sulpiride (10 or 20 mg/kg, i.p.) have no significant effect. Our results demonstrated for the first time that venlafaxine strongly attenuates morphine withdrawal and morphine-induced reaquisition of     

The protective potency of two commonly used cardioplegic solutions on cultured endothelial cells exposed to free-oxygen radicals injury

Human umbilical vein endothelial cells were incubated with Bretschneider and St. Thomas II cardioplegic solution followed by a stimulation with cumene hydroperoxide (CHPO), which was used as an oxygen radicals generating agent. A statistically significant decrease of intracellular high energy phosphates (adenosine-5-triphosphate: ATP; creatine phosphate; CP) compared to controls was observed in response to Bretschneider cardioplegia and CHPO. Furthermore, significant rises in prostaglandin I₂ (prostacyclin; PGI₂) production and lipidperoxidation were measured. The authors failed to record such alterations of endothelial cell metabolism for the St. Thomas II cardioplegic solution. They could also demonstrate that the cellular protection against oxygen radicals exerted by the St. Thomas II solution is attributable to procaine. The enhanced cytotoxicity of CHPO observed in presence of the Bretschneider solution was found to be partially caused by its constituent -histidine, which led to significant decreases of high energy phosphates and increased lipidperoxidation when cells were subsequently treated with CHPO. However, alterations of high energy phosphate content initiated by CHPO and amplified by the Bretschneider solution could not be inhibited by adding procaine. Simultaneous pretreatment of cells with the Bretschneider solution and procaine and stimulation with CHPO resulted in decreases of ATP and CP, as observed using the Bretschneider cardioplegia alone.     

Effect of blockers of serotonin and noradrenaline synthesis on learning with emotionally different reinforcement in rats]

The effect of inhibitor of serotonin and norepinephrine synthesis in the brain on learning was investigated in rats with emotionally different reinforcement. Parachlorphenylalanine (320 mg/kg) was shown to inhibit learning with food reinforcement, but facilitated learning with pain reinforcement. Disulfiram (100 mg/kg) inhibited learning with pain reinforcement considerably, but failed to influence learning with food reinforcement. Alpha-methyl-m-thyrosine inhibited both forms of learning. These new facts are in line with our previous data on mediating role of the brain monoaminergic systems between emotions and memory.     

Transglutaminase-mediated transamidation of serotonin, dopamine and noradrenaline to fibronectin: Evidence for a general mechanism of monoaminylation

The activity of some small GTPases is regulated by covalent transamidation of serotonin (5-hydropxytryptamien) to glutamine residues of the enzymes. This process is mediated by transglutaminase (TGase) and is termed “serotonylation”. In addition, serotonylation of neural proteins and proteins of the extracellular matrix such as fibronectin has been demonstrated. Here we show that the catecholamines dopamine (DA) and noradrenaline (NA) inhibit serotonylation of fibronectin and that DA and NA themselves can be selectively transamidated into fibronectin by TGase. All three biogenic monoamines also block TGase-mediated transamidation of another monoamine, monodansylacadaverine, into fibronectin, suggesting a general mechanism of TGase-mediated “monoaminylation”.     

Survival and changes in growth of juvenile tench (Tinca tinca L.) fed defined diets commonly used to culture non-cyprinid species

The study is an attempt to evaluate the feasibility of intensive tench culture using non‐specific diets as a preliminary step to check the acclimatization of the species under intensive rearing systems. Five‐month‐old juvenile tench were reared in recirculating systems at mean water temperatures of 22°C for 75 days. Fish fed with four different commercial diets (trout starter, trout first feeding, sea‐bass and eel), showed significantly higher final weights than the fish fed either eel or sea‐bass diets. Initial weight for all treatments was 2.3 ± 0.53 g. Final weight for the commercial diet groups was 3.56 ± 0.4 g, compared with the remaining groups that reached 2.09 ± 0.47 g (P < 0.05). Significantly higher survival rates were observed in the eel and sea‐bass groups (84.7 and 51.5%, respectively) than in either of the trout diet groups (38%). Specific growth rates (1.26 vs –0.18) and condition factor (1.26 vs 0.93) were also higher than those fed with salmonid diets (P < 0.05). Results obtained in this study indicate that regardless of the species’ slow growth, when compared with other cyprinids, final growth rates and survival of tench fed exclusively on sea‐bass or eel diets can be considered satisfactory. It must be pointed out that these promising results were obtained at lower temperatures than previous studies of tench in culture systems. The use of belt feeders did not show improvement in growth compared with manually fed fish when trout diets were used.     

Effects of insulin and streptozotocin-induced diabetes on brain tryptophan and serotonin metabolism in rats

Previous work by other authors has shown hat insulin administration increases brain tryptophan levels and serotonin (5–HT) metabolism. The present study partially replicates these results and tests whether these effects could be due to insulin-induced hypoglycemic stress, since stressers such as immobilization or food deprivation also increase brain tryptophan and 5-HT metabolism. Ingestion of a dextrose solution by rats administered insulin (2 I.U./kg) prevents the extreme fall in blood glucose concentration and rise in plasma corticosterone following insulin injections alone. This treatment, however, produces a larger increase in brain tryptophan (30%) than insulin-injected rats allowed only tap water. The greater accumulation of brain tryptophan may reflect an additive effect of the endogenously released insulin to that exogenously administered, since ingestion of the dextrose solution could trigger insulin secretion. In addition, brain tryptophan and 5-HT metabolism were measured in streptozotocin-diabetic rats maintained on several different feeding schedules to control for the effects of hyperphagia. All groups of diabetics showed significant decreases of approx 30% in brain tryptophan concentrations, while 5-HT metabolism was unchanged. This deficit in brain tryptophan is reversed within 2 h after insulin administration (2 I.U./kg). These results indicate that changes in brain tryptophan and 5-HT metabolism following insulin injections are not due to hypoglycemic stress, and that brain tryptophan is low in diabetics but increases above normal after administration of insulin. The results are discussed with respect to the effects of insulin on plasma levels of the neutral amino acids and a possible direct effect of insulin on the uptake of tryptophan by brain.     

Estimation of genetical parameters for a quantitative trait subject to major gene influences

Both regression and correlation estimates of genetical variance and heritability for a quantitative trait influenced by a major gene can be obtained from the error variance-covariance matrix of MANOVA using relative-relative phenotype pairs as factors. The method is illustrated with parent-offspring data on red cell acid phosphatase phenotypes and serum acid phosphatase activity.     

A cell-based high-throughput assay system reveals modulation of oxidative and nonoxidative glucose metabolism due to commonly used organic solvents.

A 96-well format screening system was generated to quantify changes in nonoxidative glucose metabolism and oxidative pyruvate metabolism. D-Glucose uptake from the supernatant media was quantified by the glucose oxidase method, and L-lactate production of cells was quantified by the lactate dehydrogenase method applied on supernatant media. Mitochondrial membrane potential was quantified using tetramethylrhodamine methyl ester (TMRM) fluorescence, and reactive oxygen species (ROS) formation was determined by quantification of dihydrodichlorofluorescein fluorescence. Adenosine triphosphate (ATP) content of myocytes was determined using the luciferin reaction, and cellular respiration was quantified using commercially available, precoated microtiter plates. These six assays were used to determine the putative influence of organic solvents, namely dimethyl sulfoxide (DMSO), ethanol, methanol, and N-methylpyrrolidone (NMP) at concentrations of 0.01, 0.1, 1.0, and 5.0% (vol/vol), respectively, on glucose and pyruvate metabolism after 4 and 24 hours. In summary, all solvents induced significant changes in regard to one or several of the parameters evaluated, affecting cellular glucose uptake, glycolysis, mitochondrial metabolism, or oxidative phosphorylation. Accordingly, this comprehensive HTS evaluation should enable researchers to choose specific organic solvents on a rational basis to avoid nonspecific effects in cultured cells and tissue culture based experimental setups.     

Influence of altitude and cold on pregnancy and lactation of rats fed on two different diets

Pregnancy and lactation in rats were investigated under standardized conditions at altitudes of 540 m and 3,450 m.There was a transitory anoestrus in some of the animals during the first 10 days at high altitude. Otherwise the conception rate and pregnancy were similar to those at ground level. Lactogenesis was delayed and lactation impaired at 3,450 m. The number of young and the mean weight of the young at day 21 of lactation was lower at 3,450 m than at 540 m.When mothers with their litters at high altitude were transferred from the usual room temperature of 21ÐC to 15ÐC lactation ceased almost completely, as was seen by the large losses of young. Lactation was also greatly impaired when mothers with litters 7 or 11 days post partum were taken from 540 m to 3,450 m altitude. A higher survival rate of the young and better growth was found when a fat enriched lactation diet was offered.

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Zusammenfassung Die Trächtigkeit und Laktation von Ratten wurde unter standardisierten Bedingungen in 540 m und 3.450 m Höhe untersucht. Bei einigen Tieren wurde in den ersten 10 Tagen in der Höhe ein Anoestrus beobachtet. Abgesehen davon war die Aufnahmequote und der Verlauf der Trächtigkeit normal.Die Galaktogenese war verzögert und die Laktation vermindert in der Höhe. Dies war erkennbar an der kleineren Zahl Junge und an dem niedrigeren mittleren Gewicht der Jungen am 21.Tag der Laktationsperiode. Die Überführung von Müttern mit ihren Würfen aus 21ÐC in 15ÐC in der Höhe von 3.450 m am 10. Tag post partum bewirkte fast vollständiges Sistieren der Laktation bei den meisten Müttern; viele Junge starben und die Überlebenden wiesen eine mangelhafte Entwicklung auf. Ebenso wurde die Laktation unterbrochen, wenn Mütter mit Würfen am 7. oder 11. Tag post partum von 540 m auf 3.450 m Höhe gebracht wurden. Die Fütterung einer fettreichen Laktationsdiät wirkte sich günstig auf die Überlebensrate der Jungen und ihr Wachstum aus.

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Resume On a examiné dans des conditions standard la durée de gestation et la lactation de rats élevés à 540 et à 3.450 m d'altitude. On a observé chez quelques individus un (Anoestrus) durant les 10 premiers jours de leur exposition à l'altitude. A part cela, la fécondité et la gestation se déroulèrent normalement.Le début de la lactation fut retardé et la durée de cette lactation raccourcie en altitude. On a pu le constater au plus petit nombre de jeunes élevés et à leur plus faible poids au 21ème jour d'alaitement. Le transport des femelles et de leurs portées d'un milieu à 21Ð dans un autre de 15ÐC (à 3.450 m d'altitude) le 10ème jour après la mise bas a provoqué un tarissement presque complet chez la plupart des femelles.De nombreux jeunes en périrent et les autres présentèrent un développement déficient. La lactation fut également interrompue par un déplacement des femelles et de leurs portées de 540 à 3.450 m d'altitude le 7ème ou le llème jour après la mise bas. Une nourriture spéciale, rich en graisse, eut un effet heureux sur le nombre de jeunes ayant survécu et sur leur croissance.