Hypothalamic and hindbrain NPY, AGRP and NE increase consummatory feeding responses

Feeding behavior is comprised of both appetitive and consummatory responses to food. Appetitive responses include the motivated acquisition of food. Consummatory responses, including swallowing, are those that move the food from the mouth to the stomach. Intraoral delivery of liquid food bypasses the requirement for appetitive responses and has been used to examine consummatory responses directly in intact rats. In the present study, we administered neuropeptide Y (NPY), agouti-related protein (AGRP) and norepinephrine (NE), into the paraventricular nucleus of the hypothalamus (PVN) or into the fourth cerebral ventricle to examine their effects on the consummatory component of feeding behavior in the rat. To measure consummatory responses, milk (40% lactose free cow's milk diluted with water) was infused intraorally through a chronic cheek fistula (1 ml/min), using an alternating 5 min on − 1 min off schedule, until rejection occurred. We found that both hypothalamic and fourth ventricle injections of NPY, AGRP and NE significantly increased consumption of the intraorally-delivered milk. Our results indicate that the circuitry for modulation of consummatory ingestive responses includes NE, NPY and AGRP receptors operating in both hypothalamic and hindbrain sites.     

大鼠冠状动脉平滑肌细胞电活动的实验研究

应用先进技术细胞内微电极的方法研究了大鼠冠状动脉平滑肌细胞的静息膜电位 (Em)及其对血管活性物质KCl、ACh、NE的反应性。结果表明 ,大鼠冠状动脉平滑肌细胞静息膜电位稳定 ,其均值为 -54.38± 2 .36mv ,KCl和ACh均可引起膜电位去极化 ,且呈剂量依赖式特点 ;NE对膜电位无明显影响。结论　同一动物的不同血管或不同动物的同一血管反应性存有明显的异质性。     

From facial mimicry to emotional empathy: A role for norepinephrine ?

Tendency to mimic others' emotional facial expressions predicts empathy and may represent a physiological marker of psychopathy. Anatomical connectivity between amygdala, cingulate motor cortex (M3, M4), and facial nucleus demonstrates a potential neuroanatomical substrate for mimicry, though pharmacological influences are largely unknown. Norepinephrine modulation selectively impairs negative emotion recognition, reflecting a potential role in processing empathy-eliciting facial expressions. We examined effects of single doses of propranolol (beta-adrenoceptor blocker) and reboxetine (selective norepinephrine reuptake inhibitor) on automatic facial mimicry of sadness, anger, and happiness, and the relationship between mimicry and empathy. Forty-five healthy volunteers were randomized to 40 mg propranolol or 4 mg reboxetine. Two hours after drug subjects viewed and rated facial expressions of sadness, anger, and happiness, while corrugator, zygomatic, and mentalis EMG were recorded. Trait emotional empathy was measured using the Balanced Emotional Empathy Scale. EMG confirmed emotion-specific mimicry and the relationship between corrugator mimicry and empathy. Norepinephrine modulation did not alter mimicry to any expression or influence the relationship between mimicry and empathy. Corrugator but not zygomaticus mimicry predicts trait empathy, consistent with greater anatomical connectivity between amygdala and M3 coding upper facial muscle representations. Although influencing emotion perception, norepinephrine does not influence emotional facial mimicry or its relationship with trait empathy.     

Influence of the polyol pathway on norepinephrine transporter reduction in diabetic cardiac sympathetic nerves: implications for heterogeneous accumulation of MIBG

Purpose Cardiac scintigraphic studies using ¹²³I-labeled metaiodobenzylguanidine ([¹²³I]MIBG) have demonstrated heterogeneous myocardial accumulation of MIBG in diabetes. The accumulation has been found to correlate with a heterogeneous decrease in the expression of norepinephrine transporter (NET). In diabetic peripheral nerve tissue, polyol pathways are activated and cause nerve dysfunction and degeneration. However, there has been little research on the polyol pathway and cardiac sympathetic nerves. Therefore, to assess the influence of the polyol pathway on cardiac sympathetic nervous function, we investigated the regional accumulation of MIBG and NET protein expression in diabetic model rats treated with aldose reductase inhibitor (ARI) for the blockade of polyol pathways.Methods Rats were given a single intravenous injection of streptozotocin (n=76, STZ-D rats). Starting the day after STZ injection, ARI was administered daily to 42 of the rats for 4 weeks (ARI-D rats). To assess the cardiac sympathetic nervous function, [¹²⁵I]MIBG autoradiographic experiments were carried out. Finally, NET protein expression was assessed with a saturation binding assay.Results The myocardial sorbitol concentration was significantly higher in STZ-D rats than in ARI-D rats. There was no heterogeneous accumulation of MIBG in ARI-D rats. There was a heterogeneous decrease of NET expression in STZ-D rats, but not in ARI-D or control rats.Conclusion The gathered data indicate that the enhanced polyol pathway correlates with the decrease in regional cardiac sympathetic nervous function, and this impairment may lead to the reduction of NET protein in cardiac sympathetic nerves of the diabetic inferior wall.An erratum to this article can be found at     

The effects of graded exercise on plasma proenkephalin peptide F and catecholamine responses at sea level

Summary The purpose of this study was to evaluate the effects of graded treadmill exercise on plasma preproenkephalin peptide F immunoreactivity and concomitant catecholamine responses at sea level (elevation, 50 m). Few data exist regarding the sea-level responses of plasma peptide F immunoreactivity to exercise. Thirty-five healthy men performed a graded exercise test on a motor-driven treadmill at the relative exercise intensities of 25, 50, 75, and 100% of maximum oxygen consumption (VO_2max). Significant (P<0.05) increases above rest were observed for plasma peptide F immunoreactivity and norepinephrine at 75 and 100% of the VO_2max and at 5 min into recovery. Significant increases in plasma epinephrine were observed at 75 and 100% of VO_2max. Whole blood lactate significantly increased above resting values at 50, 75, and 100% of the VO_2max and at 5 min into recovery. These data demonstrate that exercise stress increases plasma peptide F immunoreactivity levels at sea level. While the exercise response patterns of peptide F immunoreactivity are similar to catecholamines and blood lactate responses, no bivariate relationships were observed. These data show that sea-level response patterns to graded exercise are similar to those previously observed at moderate altitude (elevation, 2200 m).Human subjects participated in these studies after giving their free and informed voluntary consent. Investigators adhered to AR 70-25 and USAMRDC regulation 70-25 on Use of Volunteers in Research. The views, opinion, and/or findings contained in this report are those of the author(s) and should not be construed as an official Department of the Army position, policy, or decision, unless to designated by other official documentation.     

Catecholamine-containing axon terminals in the hypoglossal nucleus of the rat: an immuno-electronmicroscopic study

Summary A correlative light and electron microscopic investigation was undertaken to determine the morphology and distribution of catecholamine (CA)-containing axon terminals in the hypoglossal nucleus (XII) of the rat. This was accomplished immunocytochemically with antibody to tyrosine hydroxylase (TH). The major findings in this study were the following: 1) Immunoreactive profiles were found throughout XII and included unmyelinated axons, varicosities, axon terminals and dendrites; 2) Nonsynaptic immunoreactive profiles (preterminal axons, varicosities) were more frequently observed (55.2%) than synaptic profiles (43.5%); 3) CA-containing axon terminals ending on dendrites were more numerous (71.8%) than those synapsing on somata (25.4%) or nonlabeled axon terminals (2.7%); 4) The morphology of labeled axon terminals was variable. Axodendritic terminals typically contained numerous small, round agranular vesicles, a few large dense-core vesicles and were associated with either a symmetric or no synaptic specialization, axosomatic terminals were often associated with a presynaptic membrane thickening or a symmetric synaptic specialization and contained small, round and a few elliptical-shaped vesicles, while axoaxonic synapses formed asymmetric postsynaptic specializations; and 5) CA-positive dendritic processes were identified in XII. These findings confirm the CA innervation of XII, and suggest a complex, multifunctional role for CA in controlling oro-lingual motor behavior.     

Vasopressin and Catecholamine Responses to 24-Hour,Steady-State Hypoxemia in Fetal Goats

The purpose of the present study was to determine the effect of prolonged hypoxemia without acidemia on fetal stress hormones. Twenty-four-hour hypoxemia was conducted in nine chronically catheterized pregnant goats to determine fetal plasma concentrations of arginine vasopressin (AVP), epinephrine (E), and norepinephrine (NE). Nine experiments were performed. Six resulted in nonacidemic, steady-state hypoxemia, and three incidentally resulted in hypoxemia with progressive acidemia. In steady-state hypoxemia, fetal PO₂ decreased significantly from 28.1 ± 2.4 Torr to 18.8 ± 2.5 Torr, fetal PCOj also decreased significantly by about 5 Torr, and pH values did not change significantly. Fetal plasma concentrations of AVP, E, and NE were significantly increased at 1 h of hypoxemia. As hypoxemia continued, AVP returned to control level by 24 h, while E and NE remained elevated throughout the hypoxemic period. In the three experiments with progressive acidemia, AVP, E, and NE increased further as fetal acidosis progressed. We conclude that fetal AVP acts as a shorter-term stress hormone than E and NE in steady-state hypoxemia. This adaptive response is present without progressive acidosis. We also conclude that accompanying acidemia is a more potent stimulus for AVP, E, and NE than isolated hypoxemia during longer-term studies.     

多巴胺或多巴胺复合去甲肾上腺素对肝移植术中患者血液动力学、氧代谢及肾功能的影响

目的评价原位肝脏移植术(OLT)中持续输注多巴胺或多巴胺复合去甲肾上腺素对血液动力学、组织氧代谢和肾功能的影响。方法拟行OLT的患者30例,ASAⅢ或Ⅳ级,随机分为2组 (n=15)。A组:术中持续输注多巴胺,初始输注速率为1-3μg·kg-1·min-1;B组:术中持续输注多巴胺复合去甲肾上腺素,初始输注速率分别为1-3μg·kg-1·min-1和0．03μg·kg-1·min-1,多巴胺输注速率不超过5μg·kg-1·min-1;术中两组均调节输注速率维持MAP 60-80 mm Hg。分别于切皮前即刻、切肝期1 h、无肝期1 h、新肝期1h和术毕测定血液动力学、组织代谢和肾功能指标。结果两组HR、 MAP均维持较平稳。无肝期两组CVP、MPAP、PAWP、CO、CI、DO2、VO2降低(P<0．05);SVR和SVRI升高(P<0．05),但均在正常范围内。术中PVR、PVRI、pH及SvO2均较平稳。乳酸浓度增高并持续到术毕。两组术中Cr和BUN均在正常范围,B组总尿量高于A组(P相似文献   

多巴胺及去甲肾上腺素对感染性休克患者血流动力学和组织氧代谢的影响

目的探讨多巴胺(DA)及去甲肾上腺素(NE)在治疗感染性休克过程中对血流动力学和组织氧代谢的影响。方法选择我科腹部外科术后感染性休克患者46例,按随机原则分别给予DA(DA组)或NE(NE组)升压治疗。分别观察入组时、入组后1~6h的血流动力学指标[心率(HR)、平均动脉压(MAP)、心排出量指数(CI)、每搏指数(SI)、体循环阻力指数(SVRI)]、混合静脉血氧饱和度(SvO2)、早期乳酸清除率、28d死亡率;每小时尿量(UV)和12h后肌酐清除率(Ccr)。结果①两组各时间点MAP、CI、SVRI比较差异均无统计学意义,DA组的HR明显高于NE组,而SI低于NE组(P0.05)。②3h后NE组SvO2值较DA组明显增高(P0.05),6h后NE组SvO2≥65%的比例也明显高于DA组;NE组早期乳酸清除率明显高于较DA组[(24.8±15.7)%vs(16.2±14.2)%,P=0.003],NE组高的早期乳酸清除率比例明显高于较DA组,③两组6h后UV以及12h末的Ccr水平无明显差异。④两组之间28d死亡率无统计学差异。结论NE在内脏灌注和组织氧代谢方面优于DA。对于腹部外科术后感染性休克患者,NE可能是更好的选择。     

多巴胺联合去甲肾上腺素对感染性休克患者肾脏功能的影响

目的研究多巴胺与去甲肾上腺素联合应用对感染性休克患者肾脏功能的影响。方法选择1996年以来在我科ICU接受治疗的感染性休克患者87例,以去甲肾上腺素最大泵注速率分为3组:其中A组28例(0．5～0．9μg·kg-1·min-1),B组30例(1．0～1．5μg·kg-1·min-1), C组29例(1．6～2．0μg·kg-1·min-1)。测定记录所有患者的平均静脉压(MAP)、心率(HR)、尿量、血尿素氮(BUN)、肌酐(CRE)、尿白蛋白(U-ALB)和β2微球蛋白(Uβ2-MG)定量及APACHEⅢ评分。结果治疗前,3组患者均有低血压、心动过速和少尿,多数患者CRE、BUN、U-ALB、Uβ2-MG和APACHEⅢ评分高于正常值上限。经过抗休克治疗,所有患者的MAP、HR、尿量及BUN、CRE均恢复到正常范围,U-ALB、Uβ2-MG定量及APACHEⅢ评分也有所恢复,但仍高于正常。结论在感染性休克的治疗中,应以恢复脏器血流灌注为首要目标,以容量复苏为主,必要时辅以多巴胺、去甲肾上腺素等血管活性药物来维持循环稳定。