Calculation of physiological acid-base parameters in multicompartment systems with application to human blood.

A general formalism for calculating parameters describing physiological acid-base balance in single compartments is extended to multicompartment systems and demonstrated for the multicompartment example of human whole blood. Expressions for total titratable base, strong ion difference, change in total titratable base, change in strong ion difference, and change in Van Slyke standard bicarbonate are derived, giving calculated values in agreement with experimental data. The equations for multicompartment systems are found to have the same mathematical interrelationships as those for single compartments, and the relationship of the present formalism to the traditional form of the Van Slyke equation is also demonstrated. The multicompartment model brings the strong ion difference theory to the same quantitative level as the base excess method.     

Modulation of plasma N-acylethanolamine levels and physiological parameters by dietary fatty acid composition in humans

N-acylethanolamines (NAEs) are endogenous lipid-signaling molecules involved in satiety and energetics; however, how diet impacts circulating NAE concentrations and their downstream metabolic actions in humans remains unknown. Objectives were to examine effects of diets enriched with high-oleic canola oil (HOCO) or HOCO blended with flaxseed oil (FXCO), compared with a Western diet (WD), on plasma NAE levels and the association with energy expenditure and substrate oxidation. Using a randomized controlled crossover design, 36 hypercholesterolemic participants consumed three isoenergetic diets for 28 days, each containing 36% energy from fat, of which 70% was HOCO, FXCO, or WD. Ultra-performance liquid chromatography-MS/MS was used to measure plasma NAE levels and indirect calorimetry to assess energy expenditure and substrate oxidation. After 28 days, compared with WD, plasma oleoylethanolamide (OEA) and alpha-linolenoyl ethanolamide (ALEA) levels were significantly increased in response to HOCO and FXCO (P = 0.002, P < 0.001), respectively. Correlation analysis demonstrated an inverse association between plasma OEA levels and percent body fat (r = −0.21, P = 0.04), and a positive association was observed between the plasma arachidonoyl ethanolamide (AEA)/OEA ratio and android:gynoid fat (r = 0.23, P = 0.02), respectively. Results suggest that plasma NAE levels are upregulated via their dietary lipid substrates and may modulate regional and total fat mass through lipid-signaling mechanisms.     

Effect of acid-base status on plasma phosphorus response to lactate

The mechanism(s) underlying the hyperphosphatemia of lactic acidosis is uncertain. We assessed the interacting influence of the acid anion and acid-base status on plasma phosphorus concentration by administering lactic acid alone, lactic acid plus sodium bicarbonate, sodium bicarbonate alone, and sodium lactate alone to four different groups of dogs. The findings of (1) no increase in plasma phosphorus concentration with lactic acid plus sodium bicarbonate versus a marked increment with lactic acid alone, and (2) no difference in the plasma phosphorus response to sodium lactate versus sodium bicarbonate indicate that acidemia is necessary for the expression of lactate-induced hyperphosphatemia. The apparent greater propensity for marked hyperphosphatemia in lactic acidosis than in other types of metabolic acidosis remains unexplained, but conceivably might relate to differences in intracellular pH and in the rate of glycolysis.     

Specific alterations of physiological parameters in competitive race walkers

Race walking is the technical and athletic expression of fast walking and it can be considered as a type of endurance performance. The purpose of this study was to examine whether 12 weeks of a specially designed training program results in the further training enhancement of endurance performance and the related physiological parameters in already well-trained race walkers competing at the national and international level. The investigation protocol consisted of determining the maximal oxygen uptake (VO2peak) and related gas exchange values using an automated cardiopulmonary exercise system and of determining blood lactate variables (aerobic threshold - LTAer and the maximal lactate steady state - MLSS) during walking with proper technique at 8, 10, 12 and 14 km·h-1 for 4 minutes without rest in between. Thereafter, the speed on the treadmill was increased by 0.5 km·h-1 every two minutes until exhaustion to determine VO2peak. After 12 weeks of a specially designed endurance training, statistically significant increases in VO2peak (61.8±8.5 mL·kg-1·min-1 pre vs. 66.9±9.5 mL·kg-1·min-1 post training; p<0.05) and blood lactate variables (VO2-LTAer and VO2-MLSS; p<0.05) were noted. The obtained results suggest that the applied training program can improve endurance and race performance in previously well trained race walkers.     

Hemoglobin from newborn calves during artificial changes in the acid-base parameters of blood

The modelling of metabolic acidosis and alcalosis states proves that AAB is capable to influence on the haemoglobin parameters and its oxiform levels in the blood of newborn animals. The quantitative redistribution of the indicated haemoglobin forms in blood of the experimental animal is estimated as compensator process and is explained by their buffer properties. The investigated regularities revealed some aspects of adaptive mechanisms manifested during the abnormal exit of the newborn organism from the respiratory-metabolic acidosis state.     

Acid lipase in rat intestinal mucosa: physiological parameters

Previous studies have shown that up to a half of infused triacylglycerol does not exit the intestine via lymphatics. This suggests the presence of a mucosal lipase which could provide fatty acids for potential transport via the portal vein. The present study describes an acid-active lipase in rat intestinal mucosa. Acid lipase was assayed using a glyceryl tri[14C]oleate emulsion (pH 5.8). Mucosal homogenates were differentially centrifuged to yield cellular organelles and cytosol. Cells were sequentially released from villi using citrate and EDTA. The enzyme was found to be most active in the proximal quarter intestine and in the upper third of villi. Its greatest activity was in the lysosomal fraction. Esophageal diversion demonstrated that lingual lipase was not the precursor of the mucosal acid lipase. Bile salts stimulated activity 3- to 5-fold, but other neutral or anionic detergents were inhibitory. Of the detergents tested, taurocholate at super critical micellar concentrations could restore activity only with SDS. Sepharose 6B chromatography suggested that the enzyme partitioned into an SDS and taurocholate mixed micelle. We conclude that mucosal acid lipase is a distinct, intrinsic enzyme of the intestinal mucosa. It is predominantly lysosomal in origin. The location of its greatest activity in the villus tips of the proximal intestine suggests that it is potentially involved in mucosal triacylglycerol disposal.     

Effect of arsenic on some physiological parameters in bean plants

The objective of the study was to investigate the effect of different arsenic concentrations on some physiological parameters of bean (Phaseolus vulgaris L.) cultivars Plovdiv 10 and Prelom in the early growth phases. Seedlings, grown in sand with Hoagland-Arnon nutrient solution in a climatic box, were treated with 0, 2, 5 mg(As) dm^–3 as Na₃AsO₄ (pH 5.5). After 5 d of As treatment, the changes in leaf gas-exchange, water potential, chlorophyll and protein contents, peroxidase activity and lipid peroxidation in roots were recorded. Physiological analysis showed a minor negative effect of arsenic at concentration 2 mg(As) dm^–3, but at the higher dosage of 5 mg(As) dm^–3 growth, leaf gas-exchange, water potential, protein content and biomass accumulation were reduced in both cultivars. The peroxidase activity and lipid peroxidation increased considerably at 5 mg(As) dm^–3, which is a typical reaction of the plants to a presence of oxidative stress.     

Comparative stability of physiological parameters during sustained anesthesia in rats

Rats were anesthetized with pentobarbital, pentobarbital and atropine, inactin [5-ethyl-5-(1'-methyl-propyl)-2-thiobarbiturate], ether and inactin, or urethane. Cardiovascular and arterial acid-base parameters were monitored over a 3-hour period of anesthesia. Heart rate, arterial pressures, and pH progressively decreased with duration of pentobarbital anesthesia. Changes observed in rats anesthetized with the thiobarbiturate, inactin, were similar although generally less severe. Most subjects treated with the barbiturates were markedly hypercapnic. Urethane anesthesia was characterized by a higher and more stable heart rate and greater pulse pressure. Arterial carbon dioxide and bicarbonate levels in the urethane group were substantially lower at all sampling times than the values obtained in the barbiturate groups.     

基于遥测技术对巴马小型猪部分生理指标的观测

目的：应用遥测技术观察巴马小型猪在清醒自由状态下心电、血压、呼吸、活动等指标昼夜波动变化。方法取雄性6月龄巴马小型猪6只,行浅表股动脉VAP血管通路植入手术,恢复7 d后,用EMAK遥测系统进行24 h连续清醒自由状态下心电、血压、呼吸、活动指标监测,并用EMAK分析软件对上述指标进行分析。结果6月龄巴马小型猪心电、血压、呼吸、活动都有昼夜节律变化,白昼心率显著高于黑夜心率（ P ＜0.01）,且白昼PR间期、QRS间期与QT间期均显著低于黑夜（P ＜0.05,P ＜0.01）,白昼平均心率为76.22次/分,黑夜平均心率为67.03次/分,白昼平均PR间期、QRS间期和QT间期分别为109.97 ms、42.72 ms、380.37 ms,黑夜平均PR间期、QRS间期和QT间期为112.32 ms、44.01 ms、389.24 ms。巴马小型猪白昼收缩压、舒张压、平均压都显著高于夜间（ P ＜0.01）,白昼平均收缩压、舒张压、平均压分别为129.57 mmHg、96.75 mmHg、111.73 mmHg,夜间平均收缩压、舒张压、平均压分别为122.81 mmHg、92.65 mmHg、106.19 mmHg,且黑夜收缩压、舒张压、平均压下降率分别为19.89％、19.05％、19.35％。另外,巴马小型猪在白昼的活动情况与呼吸频率都要显著高于夜间（ P ＜0.01）。结论利用遥测技术可以对清醒自由状态下巴马小型猪心电、血压、呼吸、活动等进行连续监测,能真实的反应小型猪在24 h内上述生理指标的变化规律,为巴马小型猪在药理毒理研究中的应用提供参考。     

Use of allometry in predicting anatomical and physiological parameters of mammals

One challenge for veterinarians, animal facilities and research scientists is the making of physiological estimates appropriate to a variety of species for which data are often either completely lacking or are incomplete. Our intent in compiling the data in this paper is to provide the best possible database of normal physiological and anatomical values primarily (though not exclusively) for four common mammalian model species: mouse, rat, dog and man. In order to make those data as accessible and applicable as possible, we have presented the results of this study in the form of body-size dependent allometric equations in which some variable (Y) is expressed as a dependent function of body mass (M) in the power-law equation, Y = aM(b). By compiling these data, it is apparent that the resultant equations are quantitatively grouped (with similar slope or 'b' values). These emergent patterns provide insights into body-size dependent 'principles of design' that seem to dictate several aspects of design and function across species among all mammals. In general, the weights of most individual organs scale as a constant fraction of body mass (i.e. the body mass exponent, b approximately equal to 1.0). Biological rates (e.g. heart rate, respiratory rate) scale as b approximately equal to -1/4. Finally, volume-rates (the product of volume and rate) such as cardiac output, ventilation and oxygen uptake vary as b approximately equal to 3/4.     

Seasonal variations in physiological parameters of phytoplankton across the North Atlantic

Variations in the shapes of the action and absorption spectra,and the physiological parameters of phytoplankton [^B, the biomass(B)-specific initial slope of the photosynthesis-irradiancecurve; the plateau of the curve; _m), themaximum quantum yield of photosynthesis], were studied. Datawere collected in the North Atlantic in five biogeochemicalprovinces for two seasons: in fall of 1992 and spring of 1993.Further, some nine independent variables were tested for theirability to predict the physiological parameters, using linearregression analyses. It was found that the parameters were morevariable between seasons than between provinces, although thedifferences in the spectral shapes between provinces were significant.It was also shown that several independent variables (aloneor in combination) were able to predict a significant fractionof the total variance in the parameters. However, the correlationbetween variables and parameters differed unsystematically bothbetween provinces and seasons. The results suggest that predictinga parameter from an independent variable would have to be carriedout at a province level: the relationship changed or disappearedwhen data from two or more provinces were pooled.     

Few intra-lake variations of physiological parameters in perch, Perca fluviatilis

Intra-lake variations in physiological parameters, representing haematology, plasma ion composition and carbohydrate metabolism, were investigated in perch (Perca fluviatilis), inhabiting a comparatively unpolluted lake. Provided the perch were subjected to a standardized procedure for capture, handling, recovery after capture, and sampling, only few and minor differences were observed in 21 parameters investigated when 3 groups were compared to a control group of perch. It is concluded that the experimental design used is suitable for the examination of the physiological status of perch in the field.