The effect of ischaemia on the activity of pyruvate dehydrogenase complex in rat heart

The effect of ischaemia on the concentration of active pyruvate dehydrogenase complex has been investigated in glucose perfused hearts of normal rats fed a normal diet or a high fat diet or starved for 48 h; and in hearts from alloxan-diabetic rats. Global ischaemia induced by low flow (approx. 1 ml/min) lowered the concentration of active complex under most of the experimental conditions employed. Parallel studies showed that anoxia and K+ arrest of the heart had effects similar to that of ischaemia and suggested that hypoxia and decreased mechanical activity of the heart may be responsible for effects of low flow ischaemia. Evidence is reviewed that the effects of low flow ischaemia, K+ arrest and anoxia may be mediated through activation of pyruvate dehydrogenase kinase by increased reduction of mitochondrial NAD+. In hearts of normal rats on a normal diet, global ischaemia induced by zero flow and regional ischaemia induced by coronary artery ligation increased the concentration of active complex. Evidence is given that this may result from a combination of anoxia and acidosis. In aerobic perfusions at 60 mmHg, concentrations of active complex were ranked in the order: normal diet greater than high fat diet greater than 48 h starved greater than alloxan diabetic. This order was maintained when the concentration of active complex was increased by perfusion at 120 mmHg or lowered by global ischaemia induced by zero flow.     

Histopathological aspects of liver under variable food restriction: Has the intense one-week food restriction a protective effect on non-alcoholic-fatty-liver-disease (NAFLD) development?

Non-alcoholic-fatty-liver-disease (NAFLD) is a clinicopathologic entity characterized by a variety of hepatic injury patterns without significant alcohol use. It has a close association with obesity, so treatment includes weight loss, control of insulin sensitivity, interventions directed at inflammation and fibrosis. There is a certain relationship between the grade and duration of food restriction and hepatic function. The objective of this work was to describe the relationship between biochemistry, autoantibodies, insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein 3 (IGFBP-3), and liver morphology in experimental rabbit groups with food restriction as compared to controls with ad libitum food (ADL) income. The experiment was performed on a total of 24 rabbits of a weaning age of 25–81 days. The first group (R1) was restricted between 32 and 39 days of age to 50 g of food per rabbit a day. The second group (R2) was also restricted between 32 and 39 days, but the rabbits received 65 g of food per rabbit a day. At the end of the experiment, the blood and liver samples were collected at necropsy. NAFLD has developed in all three groups. There was any autoantibody positivity in all three groups. IGF-I is moderately higher in R1 and R2 group, as compared to the control group (P > 0.05). IGFBP-3 is without statistical significance in all three groups. Alkaline phosphatase (ALP) is the only liver biochemical parameter that has significantly increased following food restriction (P > 0.039). Single one-week restriction has any protective effect on NAFLD development.     

Undernutrition during hyperoxic exposure induces CYP2E1 in rat liver

Induction of cytochrome P450 2E1 (CYP2E1) has been shown to occur through two distinct mechanisms. The first is seen by treatment of rats with acetone, pyrazole, and 4-methyl-pyrazole, which induces CYP2E1 protein without affecting the mRNA level. The second is observed in starvation, diabetes, and obesity, in which an increase of CYP2E1 protein is associated with an increase of the CYP2E1 mRNA. It has been reported by (Tindberg and Ingelman-Sundberg 1989) that hyperoxic exposure (95% O₂) induced a several-fold increase of CYP2E1 protein in both the liver and lung of exposed rats without affecting the level of CYP2E1 mRNA. During the course of our previous study which demonstrated hyperoxia-induced specific pretranslational induction of CYP1A1/2 in the liver and CYP1A1 in the lung, we observed a progressive increase of hepatic CYP2E1 mRNA in animals of the hyperoxia group. Hyperoxia is accompanied by some degree of starvation and our earlier experiments were conducted with rats of significantly greater body weight than those used by Tindberg and Ingelman-Sundberg (260 vs 150 g). Thus we reevaluated the changes of CYP2E1 in the current study with the use of food-restricted control, and by utilizing rats of comparable weight (∼150 g) to that utilized by Tindberg and Ingelman-Sundberg. The results obtained in the present study showed that there was a significant increase in the levels of hepatic CYP2E1 mRNA, protein, and p-nitrophenol hydroxylase activity in the food-restricted control group compared to the untreated controls. Rats from the hyperoxia group also demonstrated a similar increase of these three parameters in their livers but showed no significant difference compared with the results of the food-restricted control group. Rats weighing ∼260 g were also examined with similar food restriction and hyperoxia, and the results were essentially similar to those obtained with the younger rats. The lungs of rats from food-restricted control and hyperoxia groups showed no increase of any of the CYP2E1 parameters. The results obtained in the current study, therefore, indicate that hyperoxia has no effect on CYP2E1 expression in both the liver and lung. Increased CYP2E1 mRNA, protein, and p-nitrophenol hydroxylase activity seen in the liver of rats, but not in the lungs, are consistent with the notion that undernutrition during hyperoxia is the underlying mechanism for this induction. Received: 29 April 1997 / Accepted: 11 June 1997     

Cetoacidosis no diabética en una mujer embarazada,debido a inanición aguda con gripe A (H1N1) concomitante e insuficiencia respiratoria

Threatening refractory metabolic acidosis due to short-term starvation nondiabetic ketoacidosis is rarely reported. Severe ketoacidosis due to starvation itself is a rare occurrence, and more so in pregnancy with a concomitant stressful clinical situation.This case report presents a nondiabetic woman admitted in intensive care for respiratory failure type 1 during the third trimester of pregnancy with a severe metabolic acidosis refractory to medical treatment.We diagnosed the patient with acute starvation ketoacidosis based on her history and the absence of other causes of high anion gap metabolic acidosis after doing a rigorous analysis of her acid-base disorder.     

Adolescent Anorexia Nervosa: Cognitive performance after weight recovery

Objective

Although there is no definitive consensus on the impairment of neuropsychological functions, most studies of adults with Anorexia Nervosa (AN) find impaired functioning in cognitive domains such as visual–spatial abilities. The objective of this study is to assess the cognitive functions in adolescents with AN before and after weight recovery and to explore the relationship between cognitive performance and menstruation.

Methods

Twenty-five female adolescents with AN were assessed by a neuropsychological battery while underweight and then following six months of treatment and weight recovery. Twenty-six healthy female subjects of a similar age were also evaluated at both time points.

Results

Underweight patients with AN showed worse cognitive performance than control subjects in immediate recall, organization and time taken to copy the Rey's Complex Figure Test (RCFT). After weight recovery, AN patients presented significant improvements in all tests, and differences between patients and controls disappeared. Patients with AN and persistence of amenorrhea at follow-up (n = 8) performed worse on Block Design, delayed recall of Visual Reproduction and Stroop Test than patients with resumed menstruation (n = 14) and the control group, though the two AN groups were similar in body mass index, age and psychopathological scale scores.

Conclusion

Weight recovery improves cognitive functioning in adolescents with AN. The normalization of neuropsychological performance is better in patients who have recovered at least one menstrual cycle. The normalization of hormonal function seems to be essential for the normalization of cognitive performance, even in adolescents with a very short recovery time.     

Acute starvation in pregnancy: a cause of severe metabolic acidosis

We report a case of starvation-induced metabolic ketoacidosis in a previously healthy 29-year-old, nulliparous woman at 32 weeks of gestation. She was admitted to hospital with mild preeclampsia associated with persistent nausea and vomiting that progressed to severe preeclampsia requiring urgent control of hypertension before caesarean delivery. Prolonged and severe vomiting limited oral caloric intake and led to starvation ketoacidosis, characterised by ketonuria and a raised anion gap metabolic acidosis that required intensive care support. Despite significant metabolic derangement the patient appeared clinically well. Intravascular volume was replenished. Fluid restriction used as part of our preeclampsia treatment regimen delayed the therapeutic administration of sufficient dextrose, which rapidly corrected her metabolic derangement when commenced after delivery. Electrolyte supplementation was given to prevent re-feeding syndrome. Both mother and baby were discharged without sequelae.     

Natural variability and response interpretation of fecundity, vertebrate-like sex-steroid levels and energy status in the New Zealand mudsnail Potamopyrgus antipodarum (Gray)

Potamopyrgus antipodarum is a promising test organism that is often used in ecotoxicology, both in laboratory and field exposures. As no data are available on the physiological variation range of its life-traits and the biomarkers it uses, we studied the variation of fecundity, steroid levels and energy reserves over the course of a year in a field population. The reproductive cycle was described and showed seasonal activity during summer and autumn. Steroid levels (17β-estradiol and testosterone) varied significantly during the year and were correlated with the reproductive cycle, which suggested a potential role for sex-steroids in P. antipodarum reproduction. Energy status also showed seasonal variations. Triglycerides (TG) seemed to be the main energy lipid, whereas cholesterol appeared to be mostly used as a structural lipid. Proteins were also involved in the reproductive cycle, but only when TG were not sufficient to support the reproductive strain, similar to cholesterol. Glycogen seemed to be used as an early reserve. Threshold values under which no reproduction occurred were defined in starved snails. We proposed a range of variation in the measured parameters, allowing for a better understanding and interpretation of their levels during laboratory or in situ exposures. The data suggest that the variability of fecundity in snails has not been fully appreciated in literature.     

Severe metabolic acidosis as a consequence of acute starvation in pregnancy

Ketoacidosis is most often due to uncontrolled diabetes mellitus. Similar metabolic changes can occur with poor dietary intake of carbohydrates or prolonged fasting. Metabolic acidosis due to prolonged fasting is rarely described in the literature. We report a case of severe metabolic acidosis as a result of prolonged fasting in pregnancy.     

蛋白质对半饥饿大鼠肠黏膜屏障的保护作用

目的:研究大鼠半饥饿状态下肠黏膜屏障的变化与补充蛋白质对其的保护作用. 方法:将48只大鼠随机分为正常对照组、50%正常饲料组、50%正常饲料+蛋白质组.2周后处死大鼠,测定小肠黏膜超氧化物歧化酶(SOD)活性、丙二醛(MDA)、DNA含量,肠系膜淋巴结(MLN)细菌移位率和血清D.木糖水平等. 结果:50%正常饲料+蛋白质组大鼠小肠黏膜DNA含量、SOD活性明显高于50%正常饲料组(P<0.05);血清D-木糖水平和MDA含量明显低于50%正常饲料组(P<0.05).结论:大鼠半饥饿状态下,增加饲料中蛋白质比例,对半饥饿大鼠肠黏膜具有一定的保护作用.