Insulin responses to administrations of amino acids and fatty acids in healthy cats

In order to compare the stimulation ability of insulin secretion, we determined changes in plasma glucose and insulin concentrations after intravenous administration of various amino acids and essential fatty acids in clinically healthy adult cats. Plasma glucose concentrations were within the normal ranges after injection of amino acids and fatty acids. Plasma insulin concentrations increased rapidly 2 to 4 min after injection of arginine, then decreased to the basal levels at 20 min in all five cats. Insulin peak responses were significantly greater in arginine injections than in normal saline (P<0.01). Areas under the curve (AUC) of plasma insulin concentrations from 0 to 10 min after injection of arginine were significantly larger than after injection of normal saline (P<0.01) and glucose (P<0.05). Increases in AUC of plasma insulin concentration from 0 to 60 min were observed after injection of arginine, leucine, alanine, and fat emulsion. Arginine had a strong insulinotropic effect, and leucine, alanine, and fatty acids had weak ones. Besides, valine, methionine, taurine and glutamine had no stimulant activity of insulin. Given the risk of glucose toxication and required time for testing, the intravenous arginine tolerance test may be useful for estimation of insulin responses in cats.     

The influence of omega-3 polyunsaturated fatty acids feeding on composition of fatty acids in fatty tissues and eggs of laying hens

The paper deals with supplementation of hen diet with oils with increased content of omega-3 polyunsaturated fatty acids (PUFA) and occurrence of fatty acids (FA) in fatty tissues and eggs of laying hens after the respective supplementation. The experiment was carried out on 30 laying hens of ISA BROWN hybrid, divided to three groups (A, B, C). For the period of three weeks the group A was administered flax-seed oil, group B served as a control and group C was fed base rations supplemented with fish oil. In addition to that the diet of groups A and C was supplemented with vitamin E as an antioxidant. Administration of the oils as a source of omega-3 PUFA increased their concentration in both the fatty tissues and egg-yolk which resulted in the change of the ratio of omega-6 and omega-3 PUFA. No influence of flax-seed and fish oil on concentration of alpha-tocopherol in egg-yolk was observed.     

Identification of halothane gene carriers by use of in vivo 31P nuclear magnetic resonance spectroscopy in pigs.

In vivo muscle 31P nuclear magnetic resonance spectroscopy was performed on 12 homozygous halothane-nonsensitive female pigs and 13 female pigs heterozygous with respect to the halothane gene. Fifteen female pigs of a third line, consisting of heterozygotes and halothane-nonsensitive homozygotes, were also available. Body weight ranged from 12 to 18 kg. Mean decrease in phosphocreatine concentration in the biceps femoris of anesthetized pigs was significantly lower for heterozygous vs homozygous pigs (3.46% vs 5.94%, P less than 0.01) after 40 minutes of halothane exposure (3%; oxygen flow, 3 L/min). Also, a statistically significant difference, with respect to the initial (7.21 vs 7.11, P less than 0.008) and end muscle pH values (7.18 vs 7.06, P less than 0.0002), was observed for homozygous vs heterozygous pigs. By means of canonical discriminant analysis, it was possible to distinguish nonsensitive homozygotes from heterozygotes (P less than 0.0001). When applying this classification method to pigs of the same strain, 2 populations (nonsensitive homozygotes, heterozygotes) emerged, with a proportion of pigs corresponding to the expected value on the basis of breeding records. In contrast to the phenotypic expression of muscular rigidity related to the malignant hyperthermia syndrome, the expression of metabolic variables (phosphocreatine, pH) was shown to be dominant.     

Assessment of the geometry of the cubital (elbow) joint of dogs by use of magnetic resonance imaging

OBJECTIVE: To assess joint geometry and highlight potential evidence of physiologic incongruity in cubital (elbow) joints of large, small, and chondrodystrophic breeds of dogs. SAMPLE POPULATION: Nonarthritic elbow joints obtained from cadavers of mature dogs of large breeds (n = 19), small breeds (14), or chondrodystrophic breeds (8). PROCEDURE: Magnetic resonance imaging was used to quantify interosseous gaps at 6 defined positions and 2 sagittal planes of the humeroantebrachial region by use of a fat-suppressed 3-dimensional gradient-echo sequence. RESULTS: Interosseous gaps in the more medially located sagittal plane were significantly narrower at the level of the anconeal process than at any other position of the joint in large-breed dogs, compared with results for small- or chondrodystrophic-breed dogs. In both sagittal planes, the gaps were significantly wider at the center of the ulnar trochlear notch than at any other position. Significant correlation between body weight and width of the interosseous gaps was found only in large-breed dogs and was found in both sagittal planes at the center of the ulnar trochlear notch (r, 0.834 and r, 0.680, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: In large-breed dogs, the interosseous gap was especially narrow at the level of the anconeal process and its diametric position. This suggests less ability to compensate intra-articular steps in dogs with short ulna syndrome, which predisposes to failure of the union between the anconeal process and olecranon. Geometric incongruity may be regarded as clinically normal in nonarthritic humeroulnar joints. The degree of geometric incongruity increases with body weight.     

多不饱和脂肪酸对家禽脂质代谢影响的研究进展

<正>大量研究表明,摄入多不饱和脂肪酸(PUFA)对人的健康有益,它可以抑制炎症、促进大脑发育、抑制肿瘤生长,还可通过降低血浆甘油三酯和胆固醇水平抗血栓及抑制动脉粥样硬化等[1]。因此,通过日粮中添加多不饱和脂肪酸来降低禽肉蛋制品中甘油三酯(TG)和胆固醇(TC)含量,生产功能性禽类产品,对维     

Basal plasma insulin and homeostasis model assessment (HOMA) are indicators of insulin sensitivity in cats

The objective of this study was to compare simpler indices of insulin sensitivity with the minimal model-derived insulin sensitivity index to identify a simple and reliable alternative method for assessing insulin sensitivity in cats. In addition, we aimed to determine whether this simpler measure or measures showed consistency of association across differing body weights and glucose tolerance levels. Data from glucose tolerance and insulin sensitivity tests performed in 32 cats with varying body weights (underweight to obese), including seven cats with impaired glucose tolerance, were used to assess the relationship between Bergman's minimal model-derived insulin sensitivity index (S(I)), and various simpler measures of insulin sensitivity. The most useful overall predictors of insulin sensitivity were basal plasma insulin concentrations and the homeostasis model assessment (HOMA), which is the product of basal glucose and insulin concentrations divided by 22.5. It is concluded that measurement of plasma insulin concentrations in cats with food withheld for 24 h, in conjunction with HOMA, could be used in clinical research projects and by practicing veterinarians to screen for reduced insulin sensitivity in cats. Such cats may be at increased risk of developing impaired glucose tolerance and type 2 diabetes mellitus. Early detection of these cats would enable preventative intervention programs such as weight reduction, increased physical activity and dietary modifications to be instigated.     

The effect of interday variation and a short-term stressor on insulin sensitivity in clinically normal cats

To determine whether there is a day-to-day variation in insulin sensitivity in cats, we subjected six clinically normal cats to four insulin-modified frequently sampled intravenous glucose tolerance tests (FSIVGTTs) over 7 days. The insulin-modified FSIVGTTs were analysed by the minimal model method. Minimal model insulin sensitivity (S(I)) averaged 2.9+/-0.4 x 10(-4) min(-1)/microU/ml (range 1.9-4.6 x 10(-4) min(-1)/microU/ml), with a mean interday coefficient of variation (CV) of 35.4+/-6.4% (range 12.8-58.5%). Glucose effectiveness (S(G)) averaged 0.029+/-0.002 min(-1)(range 0.024-0.037 min(-1)), and showed less interday variability with a mean CV of 24.7+/-4.3% (range 7.9-39.3%). Insulin sensitivity was also measured after a short-term stressor (5-min spray bath) of sufficient magnitude to elevate blood glucose levels. The mean insulin sensitivity after the stressor was 3.6+/-0.8 x 10(-4) min(-1)/microU/ml (range 1.6-7.3 x 10(-4) min(-1)/microU/ml), which was not significantly different to the mean insulin sensitivity before the short-term stressor (P=0.237). The mean glucose effectiveness after the stressor was 0.046+/-0.004 min(-1)(range 0.032-0.057 min(-1)), which was significantly different from mean glucose effectiveness before the short-term stressor (P=0.003). We conclude that insulin sensitivity is highly variable from day to day in normal cats, and that hyperglycaemia in response to short-term stressors is probably due to increased hepatic glucose production, rather than peripheral insulin resistance.     

The influence of different fiber types on the fecal nitrogen excretion and the content of volatile fatty acids in the feces of broiler hen breeds

4 colostomized adult broiler breeding hens each received 120 g mixed feed per day. In addition, the animals were given 10, 20, 30 and 40 g/day cellulose powder or apple pectin resp. and 10, 20, 30 g/day straw cellulose. The DM content of the faeces was increased by cellulose powder and decreased by pectin (P less than 0.01) in comparison to the control group. DM excretion in g/animal and day increased more quickly after supplementing cellulose powder than after supplementing pectin. Straw cellulose produced results in between. The fibre supplements increased N excretion in faeces. It was, however, only significantly increased per 100 g DM intake by large pectin supplements (greater than 20 g). The TCA soluble N quota in the total N of the faeces remained largely unchanged after pectin supplements and increased after cellulose and straw cellulose supplements. Pectin supplements significantly increased the formation of acetate, propionate and butyrate in comparison to the other groups. Propionate could sporadically be detected in the faeces of the other test animals, butyrate not at all. In combination with 40 g apple pectin/animal and day, Bisergon (chinoxalin derivative) increased the formation of the 3 volatile fatty acids significantly.     

Pseudolayering artefact on postcontrast magnetic resonance images of the bladder of 18 dogs and three cats

An artefact was observed on postcontrast magnetic resonance imaging (mri) of the urinary bladder of several small animals; it took the form of a dark layer in the dependent (dorsal) part of the bladder, with a thin hyperintense layer on top of it, and a hypointense signal in the rest of the non-dependent (ventral) part. The mri database was searched for animals with T1-weighted images of the urinary bladder after the injection of gadolinium. Eighteen dogs and three cats were included in the study. The artefact was observed in 16 of the animals on the postcontrast images but not on the T1-weighted and T2-weighted precontrast images. A phantom experiment showed that the signal intensity observed on T1-weighted images decreased rapidly as the concentration of gadolinium increased from 6.25 mmol/l to 25 mmol/l. It is hypothesised that the early excretion of concentrated gadolinium into the bladder causes the pseudolayering artefact observed, which has also been reported in human patients.     

Comparison of myocardial contrast enhancement via cardiac magnetic resonance imaging in healthy cats and cats with hypertrophic cardiomyopathy

OBJECTIVE: To quantify myocardial contrast enhancement (MCE) of the left ventricle (LV) by use of cardiac magnetic resonance imaging (CMRI) in healthy cats and cats with hypertrophic cardiomyopathy (HCM) and to compare MCE between the 2 groups. ANIMALS: 10 healthy cats and 26 Maine Coon cats with moderate to severe HCM but without clinical evidence of congestive heart failure. PROCEDURE: Anesthetized cats underwent gradient echo CMRI examination. Short-axis images of the LV were acquired before and 7 minutes after IV administration of gadolinium dimeglumine. Regions of interest were manually traced in the quadrants of 5 mid-LV slices acquired at end systole, and the MCE percentage was calculated from summed weight-averaged data from all slices. Doppler tissue imaging echocardiography was performed to measure the early diastolic myocardial velocity (Em) as an index of diastolic function. Three-way repeated-measures ANOVA was used to determine differences in MCE between cats with HCM and healthy cats. Simple linear regression was used to assess whether MCE was correlated with LV mass, LV mass index (LVMI), or Em. A Student t test was used to compare the SDs of the postcontrast myocardial signal intensity between the 2 groups. RESULTS: There was no difference in MCE between cats with HCM and healthy cats. There was no correlation of MCE with LV mass, LVMI, or Em. There was no difference in heterogeneity of signal intensities of LV myocardium between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE: Contrast-enhancement CMRI was not useful in detecting diffuse myocardial fibrosis in cats with HCM.     

金属硫蛋白对应激猪血液和肌肉中非酯化脂肪酸及肌乳酸含量的影响

采用驱赶法使乳猪产生应激,探讨金属硫蛋白对应激猪血清与肌肉中非酯化脂肪酸及肌乳酸含量的影响.结果表明:在应激状态下,金属硫蛋白可使血清和运动初期肌肉中的非酯化脂肪酸含量升高,肌乳酸的生成降低,因而可增强有氧代谢,改善机体对运动负荷的压力,提高动物的抗应激能力,因此金属硫蛋白对乳猪具有一定的应激保护作用.     

Determination of reference values for glucose tolerance, insulin tolerance, and insulin sensitivity tests in clinically normal cats

OBJECTIVE: To determine reference values and test variability for glucose tolerance tests (GTT), insulin tolerance tests (ITT), and insulin sensitivity tests (IST) in cats. ANIMALS: 32 clinically normal cats. PROCEDURE: GTT, ITT, and IST were performed on consecutive days. Tolerance intervals (ie, reference values) were calculated as means +/- 2.397 SD for plasma glucose and insulin concentrations, half-life of glucose (T1/2 glucose), rate constants for glucose disappearance (Kglucose and Kitt), and insulin sensitivity index (Si). Tests were repeated after 6 weeks in 8 cats to determine test variability. RESULTS: Reference values for T1/2glucose, Kglucose, and fasting plasma glucose and insulin concentrations during GTT were 45 to 74 minutes, 0.93 to 1.54 %/min, 37 to 104 mg/dl, and 2.8 to 20.6 microU/ml, respectively. Mean values did not differ between the 2 tests. Coefficients of variation for T1/2glucose, Kglucose, and fasting plasma glucose and insulin concentrations were 20, 20, 11, and 23%, respectively. Reference values for Kitt were 1.14 to 7.3%/min, and for SI were 0.57 to 10.99 x 10(4) min/microU/ml. Mean values did not differ between the 2 tests performed 6 weeks apart. Coefficients of variation for Kitt and SI were 60 and 47%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: GTT, ITT, and IST can be performed in cats, using standard protocols. Knowledge of reference values and test variability will enable researchers to better interpret test results for assessment of glucose tolerance, pancreatic beta-cell function, and insulin sensitivity in cats.     

多不饱和脂肪酸对家禽脂质代谢影响的研究进展

日粮添加多不饱和脂肪酸(PUFA)可以影响家禽脂质代谢,本文主要从PUFA的种类和来源及PUFA对家禽脂质代谢影响的研究进展作一综述.     

Assessment of the influence of surgical technique on postoperative pain and wound tenderness in cats following ovariohysterectomy

Elective ovariohysterectomy was performed on 66 cats. Surgical approach was flank (group F) or midline (group M) allocated by block randomisation. Pre-anaesthetic medication was acepromazine (0.1 mg/kg) via intramuscular injection. Anaesthesia was induced with intravenous thiopentone, and maintained with halothane in 100% oxygen. Carprofen (4 mg/kg) was administered by the subcutaneous route immediately after induction of anaesthesia. Postoperative pain and wound tenderness were assessed at 1, 3, 6, 9, 11-12 and 20-24h after the end of surgery, and the assessment outcome marked on visual analogue scales (VAS). Intervention analgesia (if pain VAS was >40 mm) was pethidine 4 mg/kg via intramuscular injection. Area under the curve (AUC) for VAS for pain and VAS for wound tenderness for each cat were calculated. AUC for wound tenderness was significantly greater for group F (P = 0.007). There was no significant difference for AUC for pain between the groups. In conclusion, wounds after flank ovariohysterectomy are significantly more tender than after midline ovariohysterectomy in the cat. This indicates that interactive methods, including wound palpation, must be used to assess postoperative pain and the findings should be appropriately weighted in the overall assessment.     

Effect of different exogenous fatty acids on the cytosolic triacylglycerol content in bovine mammary cells

The objective of this study was to determine how cytosolic triacylglycerols (TAG) are stored in mammary cells and whether this depends on the individual chemical configuration of fatty acids (FA). This objective was accomplished by addition of different FA to a FA-free medium used to culture mammary alveolar cells-large T antigen cells (MAC-T). Treatments consisted of adding FA (palmitate, stearate, oleate, linoleate, rumenic acid [CLA], elaidate and vaccinate) solutions to the medium at 100, 200, 300 and 400 mmol/L concentrations for a 24-h incubation period. At the end of each incubation period, cytosolic TAG, DNA and protein contents were measured. Palmitate, vaccenate, linoleate and CLA increased (P < 0.05) cytosolic TAG (μg/mg protein). Palmitate and CLA increased (P < 0.05) cytosolic TAG adjusted for DNA content. Overall, effects on cytosolic TAG accumulation depended on individual FA structure (chain length, degree of saturation, and number and orientation of FA double bonds). In addition, the long-chain FA used in this study did not have a detrimental effect on MAC-T cells as indicated by cytosolic protein and DNA contents reflecting their biological role in lipid accumulation.     

Studies on acid oils and fatty acids for chickens. II. Effect of free fatty acid content and degree of saturation of free fatty acids and neutral fat on fatty acid digestibility

1. Two experiments were designed to study the influence of free fatty acid content and degree of saturation of free fatty acids and neutral fat on digestibility of added fats and fatty acids. Sunflower oil and tallow were used as neutral fats, and palmitic, stearic, oleic and linoleic acids as free fatty acids. Fat inclusion was 80 g/kg and mixtures of each fat and each free fatty acid were prepared in the proportions 100:0, 70:30 and 40:60.

2. Experimental diets were evaluated for fat and fatty acid digestibilities with broiler chickens at 21 d of age. The metabolisable energy of fat was calculated from the product of digestibility and gross energy. Increasing concentrations of saturated free fatty acids decreased the ME of added fat, whereas unsaturated free fatty acids did not significantly affect the ME value of added fat.

3. Digestibilities of individual fatty acids were analysed by linear regression with rate of inclusion of free fatty acid in the fat blend: palmitic and stearic acids gave a negative slope, whereas oleic and linoleic acids gave a slope not statistically different from zero. Because slopes for saturated fatty acids did not differ between the sunflower oil and tallow treatments, synergism between unsaturated and saturated fatty acids was not detected.