Acetylcholinesterase Adaptation to Voluntary Wheel Running is Proportional to the Volume of Activity in Fast, but not Slow, Rat Hindlimb Muscles

Chronic enhancement of neuromuscular activity by forced exercise training programmes results in selective adaptation of the G₄ acetylcholinesterase (AChE) molecular form in hindlimb fast muscles of the rat, with only minor and non-selective AChE changes in the soleus. In order to shed further light on the physiological significance of this G₄ adaptation to training, we turned to a voluntary exercise model. The impact of 5 days and 4 weeks of voluntary wheel cage running on AChE molecular forms was examined in four hindlimb fast muscles and the slow-twitch soleus from two rat strains. Inbred Fisher and Sprague– Dawley rats, placed in live-in wheel cages, exercised spontaneously for distances which progressively increased up to an average of ∼3 and 18 km/day, respectively, by the end of week 4. Fast muscles responded to this voluntary activity by massive G₄ increases (up to 420%) with almost no changes in A₁₂, so that by week 4 the tetramer became the main AChE component of these muscles. The additional G₄ was composed primarily of amphiphilic molecules, suggesting a membrane-bound state. The G₄ content of fast muscles was highly correlated with the distance covered by the rats during the 5 days before they were killed ( r = 0.850-0.879, P < 0.001 in three muscles). The soleus muscle, in turn, responded to wheel cage activity by a marked selective reduction of its asymmetric forms—up to 45% for A₁₂. This A₁₂ decline, already maximal by day 5 of wheel cage running, showed no relationship with the distance covered. The present results constitute strong new evidence suggesting that the role of AChE in neuromuscular transmission is not limited solely to the rapid inactivation of just-released acetylcholine.     

Fractionation of a chalone-containing preparation from Ehrlich's ascites tumor by high performance liquid chromatography

Department of Biology, Medico-Biological Faculty, and Applied Research Laboratory of Ecology, Toxicology, and Metabolism of Medicinal Preparations, attached to the Department of Biochemistry, Medico-Biological Faculty, N. I. Pirogov Second Moscow Medical Institute. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 112, No. 10, pp. 418–419, October, 1991.     

Low peripheral plasma renin activity as a critical marker in pediatric hypertension

In evaluating hypertensive children and adolescents, the etiological considerations should include a set of inherited disorders that share very low plasma renin activity (PRA) as a common feature. In particular among these disorders, glucocorticoid remediable aldosteronism (GRA) appears to be emerging as an important etiology of hypertension in the pediatric population. We report the evaluation of a 9-year-old Caucasian girl who presented with severe hypertension and a strong family history of early-onset hypertension. Her suppressed PRA, her family history, and her failure to respond to conventional antihypertensive therapy raised GRA as a potential etiology. The diagnosis was confirmed by an elevated ratio of urinary 18-oxotetrahydrocortisol to urinary tetrahydroaldosterone and genetic testing, which demonstrated the chimeric gene duplication. The molecular pathogenesis of GRA and the clinical implications are reviewed. Received May 15, 1996; received in revised form and accepted September 16, 1996     

参加社会活动和锻炼对冠心病并发抑郁的影响1

目的：研究参加社会活动和锻炼对新兴工业化农村社区冠心病患者并发抑郁的影响。方法：对114例在我院就医、属三角镇户籍常住人口的冠心病（CHD）患者进行Zung量表（SDS量表）检测，同时调查其经济状况、健康习惯、参加社会活动和锻炼情况等。用SPSS13．0版统计软件进行统计分析。结果：抑郁发生率37．7％，女性44．3％（27／61）高于男性30．2％（16／53）。70岁以上者47．6％（30／63）高于70岁以下者25．5％（13／51）。缺少社会活动（几乎不参加社会活动）、缺少锻炼（几乎不锻炼身体）都抑郁发生率高，可能是冠心病并发抑郁的独立预测因素。结论：适度参加社会活动和锻炼对CHD患者并发抑郁可能有预防作用。     

The effects of norepinephrine transporter inactivation on locomotor activity in mice.

BACKGROUND: Acute administration of different classes of antidepressants can enhance or reduce spontaneous locomotor activity in a novel environment, but the effects of chronic antidepressant treatment on spontaneous locomotor activity in novel and familiar environments are less well characterized. Because norepinephrine is an important regulator of spontaneous locomotor activity, we speculated that norepinephrine transporter blockade contributes to the effects of some antidepressants on spontaneous locomotor activity. METHODS: Antidepressant drugs (reboxetine, desipramine, imipramine, venlafaxine, bupropion) were administered acutely (intraperitoneal) or chronically (via osmotic minipump) to control and norepinephrine transporter knockout mice, and spontaneous locomotor activity in novel or familiar environments was recorded. RESULTS: Acute treatment with most norepinephrine transporter-blocking antidepressants decreased spontaneous locomotor activity in a novel environment, whereas chronic treatment decreased spontaneous locomotor activity in both novel and familiar environments. The exception was bupropion, a dual norepinephrine transporter/dopamine transporter blocker, which tended to increase spontaneous locomotor activity. Coadministration of reboxetine and the dopamine transporter blocker GBR 12909 also increased spontaneous locomotor activity. Norepinephrine transporter knockout mice had low basal spontaneous locomotor activity, which was increased by bupropion, whereas reboxetine had no effect in norepinephrine transporter knockout mice. CONCLUSIONS: Acute or chronic inactivation of the norepinephrine transporter decreases spontaneous locomotor activity in novel and familiar environments unless coupled with dopamine transporter blockade.     

Corticofugal modulation of the information processing in the auditory thalamus of the cat

Summary Single unit activity of 355 cells was recorded in the auditory thalamus of anesthetized cats before, during, and after the inactivation by cooling of the ipsilateral primary auditory cortex (AI). Most of the units (n = 288) showed similar functional characteristics of firing before and after the cryogenic blockade of AI. The spontaneous firing rate remained unchanged by cooling in 20% of the units and decreased in the majority of them (60%). In some regions, i.e. dorsal division of the medial geniculate body (MGB), lateral part of the posterior group of the thalamus, and auditory sector of the reticular nucleus of the thalamus, the maximum firing rate evoked by white noise bursts was generally affected by cooling in the same direction and to the same extent as the spontaneous activity. Units in the ventral division of MGB showed a characteristic increase of signal-to-noise ratio during cortical cooling. The corticofugal modulation led to the appearance or disappearance of the best frequency of tuning in 51 units and changed it by more than 0.5 octave in 34 units. The bandwidths of different response patterns to pure tones stimulation were used to define a set of functional properties. During cryogenic blockade of AI, two cortically modulated sub-populations of units were usually distinguished that exhibited changes for a given functional property. The complexity and diversity of the effects of cortical inactivation suggest that the corticothalamic projection may be the support for selective operations such as an adaptive filtering of the incoming acoustic signal at the thalamic level adjusted as a function of cortical activity.     

钩端螺旋体核糖体提取物免疫保护作用的研究

作者对核糖体现有的制备方法进行了部分改进,从黄疸出血群赖型017株钩体中成功地制备了核糖体提取物。该提取物经SPA-ELISA 证实具有免疫原性,对40只受试豚鼠的保护试验结果表明,核糖体提取物对同型毒株的攻击具有明显的保护作用;结果还证明核糖体提取物能诱导机体的体液免疫反应。     

Substance P and human nasal mucociliary activity

Summary Substance P (SP), a potent inflammatory agent, has been found in sensory nerve fibres in the nasal mucosa in several experimental animals as well as in man. It may participate in the inflammatory response as part of the mucosal defence against foreign materials. In experimental animals SP has been found to increase mucociliary in airway mucosa. The present study was performed in order to find out the relationship between topically applied SP and nasal mucociliary function in humans. Thirteen healthy volunteers were challenged with 65 µg SP or placebo in a randomized cross over fashion and mucociliary transport time was determined each time using the saccharine dye test. The dose of SP was chosen after an open dose-response study. No statistically significant change in the mucociliary transport time was found after challenge with SP as compared to placebo. The possible reasons for this are discussed.     

Apomorphine-induced alterations in cortical EEG activity of rats

Summary EEG activity after activation of dopamine receptors of D-1 and/or D-2 type was studied by using telemetric recordings in rats. Apomorphine, a preferential D-2 agonist, produced a characteristic increase in the power of alpha-1 band (7.00–9.50 Hz) when given in doses mediating stereotypies (0.2 or 0.5 mg/kg s. c.). Low doses produced a general increase in the power of all of the bands except beta-2. In particular, delta activity was enhanced which seems to be in correspondence with the sedation observed after these doses (0.02 and 0.05 mg/kg). Haloperidol in a dose which is assumed to block both D-1 and D-2 receptors (0.1 mg/kg i. p.) completely antagonized the alpha-1 activation produced by apomorphine (0.5 mg/kg). A similar, although not complete inhibition of alpha-I activation was found after administration of a large dose of the selective D-1 antagonist SCH 23390 (0.2 mg/kg i. p.). The selective agonist at D-2 receptors quinpirole (1.0 mg/kg s. c.) produced a less pronounced activation of the power in the alpha-1 band than apomorphine.In general, there was found to be a good correlation between the activation of the alpha-1 activity and stereotyped behaviour. The results suggest that for the full expression of alpha-1 activation, a pronounced activation of D-2 receptors and at least a minimal activation of D-1 receptors, for instance by the endogenous dopamine, is necessary. Send offprint requests to K. Kuschinsky at the above address