丁基苯酞对缺血脑组织中及低糖低氧刺激后培养的神经细胞中胆碱乙酰化酶活性的影响

 目的:观察丁基苯酞(dl-NBP),d-NBP和l-NBP对脑缺血后皮层和纹状体中以及低糖低氧和NMDA刺激后培养的胎鼠皮层神经元中胆碱乙酰化酶活性变化的影响?方法:大脑中动脉堵塞起始处造成大鼠局灶性脑缺血;胎鼠皮层神经元以低糖低氧培养基培养造成低糖低氧模型;胆碱乙酰化酶活性以分光度法进行测定?结果:脑缺血后缺血区皮层和纹状体中胆碱乙酰化酶活性分别下降了61.3%和58.4%?dl-NBP,d-NBP和l-NBP(10和20mg·kg^-1,ip)于脑缺血后5和60min给药2次皆可显著提高脑组织中胆碱乙酰化酶活性?dl-NBP,d-NBP和l-NBP(0.1～10μmol·L^-1)对低糖低氧及NMDA刺激后神经细胞中胆碱乙酰化酶活性也有明显的提高作用?结论:dl-NMP改善局灶性脑缺血后动物的学习记忆功能可能与其对胆碱能神经功能的改善有关?     

丁基苯酞对缺血脑组织中及低糖低氧刺激后培养的神经细胞中胆碱乙酰化酶活性的影响

目的：观察丁基苯酞（ｄｌＮＢＰ）,ｄＮＢＰ和ｌＮＢＰ对脑缺血后皮层和纹状体中以及低糖低氧和ＮＭＤＡ刺激后培养的胎鼠皮层神经元中胆碱乙酰化酶活性变化的影响。方法：大脑中动脉堵塞起始处造成大鼠局灶性脑缺血;胎鼠皮层神经元以低糖低氧培养基培养造成低糖低氧模型;胆碱乙酰化酶活性以分光度法进行测定。结果：脑缺血后缺血区皮层和纹状体中胆碱乙酰化酶活性分别下降了６１．３％和５８．４％。ｄｌＮＢＰ,ｄＮＢＰ和ｌＮＢＰ（１０和２０ｍｇ·ｋｇ－１,ｉｐ）于脑缺血后５和６０ｍｉｎ给药２次皆可显著提高脑组织中胆碱乙酰化酶活性。ｄｌＮＢＰ,ｄＮＢＰ和ｌＮＢＰ（０．１～１０μｍｏｌ·Ｌ－１）对低糖低氧及ＮＭＤＡ刺激后神经细胞中胆碱乙酰化酶活性也有明显的提高作用。结论：ｄｌＮＭＰ改善局灶性脑缺血后动物的学习记忆功能可能与其对胆碱能神经功能的改善有关。     

INTERRELATION BETWEEN FATTY ACID OXIDATION AND CONTROL OF GLUCONEOGENIC SUBSTRATES IN SMALL-FOR-GESTATIONAL-AGE (SGA) INFANTS WITH HYPOGLYCEMIA AND WITH NORMOGLYCEMIA

ABSTRACT. Twelve SGA infants were studied from 4 hours after birth (day 1), before and for 4 hours after injection of 0.5 g of fat/kg b. w. (Intralipid®, IL). Eight infants were restudied after 24 hours (day 2). A positive correlation was found between initial samples of FTA and glucose on day 1 (n= 11, r 0.71, p < 0.02) and between FFA and β-hydroxybutyrate (n= 12, r 0.62, p < 0.05), suggesting low FFA mobilization and oxidation in SGA infants with low blood glucose. After IL infants with low blood glucose had a more pronounced defect of intravascular lipolysis. Four infants had initial hypoglycemia (HG), with blood glucose 0.4-1.3 mmol/l, and 8 were normoglycemic (NG). In the NG group initial levels of lactate and alanine were within normal limits, and no changes occurred after IL. An early peak of glycerol was seen. In the HG group initial lactate and alanine levels were higher than in the NG group, while glycerol did not differ. After injection of IL, glucose increased at 60 and 120 min in the HG group. A close correlation was found between mean levels of lactate and alanine and a negative correlation between lactate and glucose, while no correlation was found between glycerol and glucose levels. The infants with the lowest initial glucose and the highest lactate levels had the steepest rise in glucose and the fastest decrease in lactate per unit increase in β-hydroxybutyrate after IL. On day 2 the initial levels of lactate and alanine were lower than on day 1 and all infants were normoglycemic. A glucose peak corresponding to the glycerol peak was seen after IL, but lactate and alanine levels did not change. These data were consistent with reduced lipolytic capacity, low fatty acid oxidation and reduced gluconeogenesis in SGA infants on day 1, especially in those with HG. The glucose and β-hydroxybutyrate levels were rapidly increasing and lactate levels decreasing after IL, suggesting improving gluconeogenesis concomitantly with increasing fatty acid oxidation.     

The Role of Glucagon,Catecholamines and Cortisol in Counterregulation of Insulin-induced Hypoglycemia in Normal Man

ABSTRACT To study the response of glucose counterregulation to insulin-induced hypoglycemia, six normals were given a 4-hour infusion of insulin (2.4 U/h) ± somatostatin (50 μg/h). Supplementary glucagon (1.5 or 3.0 ng/kg/min) was given in additional experiments. In a separate study, glucagon was supplemented for 4 hours as a constant rate infusion (3.25 ng/kg/min) or at rates stepwise increasing from 1.5 to 5.0 ng/kg/min. Insulin decreased blood glucose by 1.5 mmol/1 and simultaneous suppression of glucagon resulted in a more pronounced hypoglycemia enhancing the adrenaline and Cortisol responses. The hyperglycemic effect of glucagon substitution (3 ng/kg/min) faded out after about 2 hours, whereafter exaggerated adrenaline and Cortisol responses to hypoglycemia were seen. A comparison between the effects of steady state hyperglucagonemia and gradually appearing hyperglucagonemia on the counterregulation of hypoglycemia revealed no significant differencies in glucose, adrenaline and Cortisol responses to insulin. It is concluded that the glycemic effect of glucagon is transient in the hypoglycemic state. When the hepatic responsiveness to this hormone is decreased during hypoglycemia, adrenaline becomes the essential protective factor.     

Higher glycemic variability in very low birth weight newborns is associated with greater early neonatal mortality

Objective: To determine the association between mean glycemia and its variability with perinatal mortality in preterm newborns hospitalized in an intensive care unit (ICU). Methods: Patients admitted to the ICU within the first 12 hours of life, with birth weight <1500?g, at least three blood glucose measurements/day and lack of insulin treatment were evaluated. Association of mean glycemia and its standard deviation (SD) with death during initial 7 days of life was evaluated. Multivariate logistic regression analysis was performed twice, using continuous glucose concentrations and by means of a quintile-based approach correcting for nonnormal distribution and nonlinear effects. Results: A total of 95 newborns were enrolled. Eleven patients (11.5%) died during the initial 7 days of life, overall mortality equaled 22%. Multivariate analysis showed that 5 minute Apgar score and SD of glucose concentrations were significantly associated with increased mortality in both models. Odds ratios (ORs) equaled 0.44; 95% confidence interval (95% CI) 0.27–0.74 and OR 1.34; 95% CI 1.03–2.03 for the continuous model and 0.50 95% CI 0.34–0.75 and OR 1.82 95% CI 1.07–3.11 for the quintile-based model. In both cases, mean glycemia was removed during the stepwise model-building procedure. Conclusions: Higher glycemic variability may be associated with greater odds of perinatal mortality.     

低血糖脑病13例临床分析

目的:探讨低血糖脑病的临床表现及产生原因。方法:13例患者按临床表现分类并完善头部CT检查。所有患者一经确诊立即给高渗糖静脉注射治疗。结果:12例患者经治疗后痊愈出院。1例死亡。结论:临床上以抽搐、偏瘫及精神异常为首发症状就诊的患者,需注意发生低血糖性脑病的可能。     

Detection of Nocturnal Hypoglycemia in Insulin-treated Diabetics by a Skin Temperature - Skin Conductance Meter

ABSTRACT The efficacy and credibility of a skin temperature - skin conductance meter (Teledyne Sleep Sentry) for detecting hypoglycemia was studied during night-time in 22 adult insulin-treated diabetics. Capillary blood glucose concentration was measured 99 times (when the alarm sounded, in case of hypoglycemic symptoms, and at 3 a.m.). Hypoglycemia was defined as a capillary blood glucose concentration of ≤3 mmol/l. Blood glucose was measured 61 times in connection with sounding of the alarm and 38 times without the alarm sounding. At 3 a.m. the Sleep Sentry sounded the alarm 22 times, of which hypoglycemia was present 6 times giving a diagnostical specificity or diagnostical true positive rate of 0.27 (95 % confidence limits 0.11–0.50). In 35 of 38 cases of no alarm the blood glucose was >3 mmol/l, giving a diagnostical sensitivity of 0.92 (95 % confidence limits 0.79–0.98). The Sleep Sentry sounded the alarm in 6 of 9 cases of hypoglycemia, giving a nosological sensitivity of 0.67 (95 % confidence limits 0.30–0.93). The Sleep Sentry did not sound the alarm in 35 of 51 cases of non-hypoglycemia, giving a nosological specificity of 0.69 (95 % confidence limits 0.54–0.81). In other words, the Sleep Sentry detects about 2/3 of blood glucose values ≤3 mmol/l, but in addition it sounds a false alarm in 2/3 of the cases.     

Lateral modulation of the hypoglycemic action of insulin

Department of Psychiatry, Voroshilovograd Medical Institute. Khar'kov Research Institute of Endocrinology and Hormone Chemistry. (Presented by Academician of the Academy of Medical Sciences of the USSR O. S. Adrianov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 107, No. 4, pp. 458–459, April, 1989.     

Adrenalectomy Prevents Changes in Rat Pineal Melatonin Content N-Acetyltransferase Activity Induced by Acute Insulin Stress

The activity of N-acetyltransferase (NAT) the content of melatonin (MEL) in the rat pineal have been shown to be sensitive to several types of stressors. This study was designed to assess the role of the adrenals in mediating the effect of one such stressor, insulin-induced hypoglycemia, on pineal synthetic activity. Intact bilaterally adrenalectomized (ADX) adult male rats were kept under light:dark cycles of 14:10 (lights on 0600 h) injected intraperitoneally with 10 IU insulin at 1300 h, groups (n = 8) were killed 2, 3, or 4 h postinjection. Plasma catecholamines were assayed by means of high performance liquid chromatography radioimmunoassay was used to assess pineal NAT activity MEL content. All injected groups were rendered hypoglycemic by insulin administration. Compared to uninjected controls, plasma epinephrine in hypoglycemic intact rats rose after 2 h, whereas epinephrine did not change in hypoglycemic ADX animals. The increase in epinephrine in intact animals was correlated with a rise in NAT activity at 2 h. Moreover, pineal MEL content at 2, 3, 4 h was significantly greater than control values. In contrast, no changes in pineal biosynthetic function were found in ADX rats. This differential response by intact ADX rats suggests that an adrenal product (possibly epinephrine) is responsible for mediating the stimulatory effects of acute insulin-induced hypoglycemic stress on the rat pineal.