Polyamine levels in brain and plasma after acute restraint or water-immersion restraint stress in mice

To investigate the relationship between polyamines and stress, we measured polyamine levels in the frontal cortex, hippocampus, hypothalamus, and plasma of mice after acute restraint or water-immersion restraint stress. In all parts of the brain, putrescine levels were elevated (139-157% of the control) 24 h after water-immersion restraint stress. In the case of restraint, however, elevation of the putrescine level (130% of the control) was detected only in the frontal cortex. Spermidine and spermine levels were unchanged or slightly reduced (80-85% of the control) in the brain 6 and 24 h after water-immersion restraint stress. There was no change in plasma polyamine levels at any time subsequent to the stress. Pretreatment with diazepam (5 mg/kg, i.p.) completely blocked the stress-induced putrescine increases. These results indicate that the magnitude of the putrescine increase is dependent upon the intensity of the stressor, and suggest that polyamine metabolism is linked to psychological stress.     

Phenotypic and functional differences between lymphocytes from NALT and nasal passages of mice

Nasal-associated lymphoid tissue (NALT) and nasal passages (NP) are considered as inductive and effector sites, respectively. The differences among lymphocyte populations of these nasal compartments have not been clearly established. The aim of this work was to contribute to the characterization of NALT and NP lymphocytes in mice. We isolated lymphocytes from both compartments, determined the frequencies of B220(+) cells as well as CD8(+), CD4(+) T cells; and analysed the expression of CD69 and CD25. Besides we analysed the proportion of T cells producing IL-2, IL-4, IL-5, IL-10, IFN-gamma and TNF-alpha. We found differences between NALT and NP. Two populations of B cells, B220+(hi) and B220+(low) were clearly distinguished only in NP, but not in NALT. Both (hi) and (low) B220(+) cells expressed CD19, but only a fraction of the B220+(low) population, expressed the plasma cell marker CD138(+). More B than T lymphocytes, as well as higher frequencies of CD4(+) than CD8(+) T cells were found in both compartments. A small fraction of NK cells (CD3(-)DX5(+)) along with a significant proportion of double negative CD4(-)CD8(-)CD3(+)DX5(-) T cells was detected in both nasal tissues. Furthermore, as expected for a mucosal effector site, NP contained major proportions of B220(+), T CD4(+) and T CD8(+) cells expressing CD25 and CD69 in comparison to NALT. Likewise, the proportion of T cells spontaneously producing IL-2, IFN-gamma, and IL-4, was higher in NP than in NALT. These data provide further evidence indicating that distinctive phenotypic and functional features exist in the lymphocyte populations residing at NALT and NP.     

Effects of acute and chronic restraint stress on nitroglycerin-induced hyperalgesia in rats

Nitric oxide (NO) plays an important role in initiation and maintenance of pain, and NO precursor nitroglycerin is able to activate spinal and brain structures involved in nociception. It is also known that acute and chronic stress induce biochemical changes affecting both pain threshold and behaviour, and that the biological pattern of depression can be mimicked in the laboratory using chronic unavoidable stress paradigms (learned helplessness). We, therefore, evaluated the effects of acute and chronic immobilization stress on pain response to nitroglycerin administration in the rat. Pain perception was expressed as the latency of response to a tail-flick test (hot stimulus). Measures were made 1, 2 and 4 h following nitroglycerin (10 mg/kg i.p.) or vehicle. Nitroglycerin caused hyperalgesia after 2 and 4 h (p < 0.05 versus baseline). Acute stress (90 min) induced a clear analgesic state (p < 0.01 versus non-stressed control animals), and nitroglycerin injection was unable to reverse stress-induced analgesia in this setting. By contrast, exposition to chronic immobilization stress (7 days) caused a significant increase in pain response (p < 0.05); in this case, hyperalgesia was shown to be further enhanced by nitroglycerin administration (p < 0.05 versus vehicle). These findings support the view that a condition of chronic stress used in the laboratory to reproduce the biological features of depression can enhance hyperalgesia induced by nitroglycerin administration. These observations may be relevant to pain disorders, and particularly to migraine, since nitroglycerin is able to induce spontaneous-like pain attacks in humans, and an unfavourable migraine outcome (transformation into a chronic daily headache) is associated with chronic stress and comorbid depression.     

Effects of restraint and water-immersion stress and insulin on gastric acid secretion in rats

Effects of restraint and water-immersion stress (RWIS) and of insulin injection on gastric acid secretion were investigated in relation to blood glucose levels and to brain glucose uptake in rats. Venous blood glucose levels (VBG) were significantly increased while arterial blood glucose level (ABG) was slightly increased by RWIS. In contrast, ABG and VBG were significantly decreased by administration of insulin; the decrease in ABG was greater than that in VBG. Glucose uptake into the brain, calculated from the ABG-VBG, was significantly decreased both by RWIS loading and by insulin administration. The uptake of [14C] 2-deoxy-D-glucose [( 14C]-2DG) into the brain was also significantly decreased in RWIS-loaded or insulin-treated rats. Gastric acid output was significantly increased both by RWIS loading and by insulin administration. The increased acid output paralleled the decrease of glucose uptake into the brain in RWIS-loaded and insulin-treated rats. Results suggest that RWIS-induced gastric acid secretion is regulated by brain glucose uptake and that this gastric acid secretion is a hypothalamic neuron-mediated event as is insulin-stimulated gastric acid secretion.     

Plasma corticosterone levels during repeated presentation of two intensities of restraint stress: chronic stress and habituation

This study measured plasma corticosterone levels in male rats during repeated daily presentations of two intensities of restraint stress. The corticosterone response to a stress session was defined as the change from pre-stress levels to levels after 60 minutes of restraint. With the relatively intense stress imposed by four limb prone restraint, the corticosterone response partially habituated over seven days due to increasing basal corticosterone levels. However, even on day 7, there was still a large corticosterone response. With the milder stress of immobilization in a tube, the corticosterone response did not habituate at all over 21 days of repeated stress despite rising basal levels. Stress levels of corticosterone did not show significant change over days in either of the two restraint groups. Further, rising basal corticosterone levels suggest that repeated restraint produced a chronic stress state in these rats which may vary in some qualitative way with stressor intensity. Control rats placed in the same room as the stressed rats during the two stresses initially had increased corticosterone levels that matched the levels achieved in the stressed rats. The responses in control rats for the intense stress did not habituate completely in 7 days, whereas those in the control rats for the mild stress habituated completely within 3 days. These data suggest intraspecific communication of the intensity of stress.     

急、慢性束缚应激对小鼠情绪和学习记忆能力的不同影响

目的:观察急性束缚应激和慢性束缚应激对小鼠情绪和学习记忆能力的影响。方法:小鼠按体重和自发活动随机分成三组,即空白对照组,急性应激组和慢性应激组。采用束缚躯体的方法建立急慢性应激模型,并用自发活动实验检测小鼠的情绪状态,避暗实验检测小鼠的学习记忆能力。结果:自发活动实验中急性束缚应激组小鼠平均速度与空白组相比有显著增加(P<0.01),中央区活动时间和中央区活动路程百分比则显著增加(P<0.05),慢性应激组平均速度与空白组相比有显著减小(P<0.01),中央区活动时间和中央区活动路程百分比显著减小(P<0.05);避暗测试中急性应激组避暗潜伏期和错误次数没有改变,而慢性应激组潜伏期显著减小(P<0.05)、错误次数急显著增加(P<0.01)。结论:急性束缚应激会使小鼠产生烦躁情绪、但不会改变其学习记忆能力;慢性束缚应激会使小鼠产生抑郁样情绪,会损害其学习记忆能力。     

Effects of two types of restraint stress on the spontaneous behaviour in rats

Our previous findings suggested the existence of stressor-specific behavioural and cognitive responses in rats. In the present study, restraint stressor (immobilization, IMO) and restraint stressor combined with partial immersion of rats into water (IMO+C) were applied for 1 hour to Wistar male rats and their spontaneous behaviour was examined in the open field test. The classic behavioural parameters were recorded: crossing, rearing, and resting. When tested 1 and 4 hours after IMO+C, animals exhibited strong suppression of locomotor and exploratory activity (crossing and rearing); partial inhibition of both behavioural variables was found after IMO. Thus, substantial differences were observed in dependence on the length of period between the end of stressor application and the start of testing. In testing performed one week later, the locomotor and exploratory activity levels of both IMO and IMO+C animals corresponded to the control ones. These data suggest a differential behavioural response to both used stressors that may result from their different proportion of psychical and physical components. In conclusion, our results provide other data for the support of differential effects of two types of restraint stressors on spontaneous behaviour of animals exposed to a novel environment.     

Effects of two types of restraint stress on the learned behaviour in rats

To study the effects of stress on cognitive functions, Wistar and Lewis rats were exposed to restraint (immobilization stressor) (IMO) or restraint combined with partial immersion into water (IMO+C). Learned discriminatory avoidance response in Y-maze, with foot-shock as an unconditioned stimulus, was used as a memory test. The latency to enter the correct arm and number of wrong entries were daily recorded during the training period (20 days) until the criterion was reached, which was set at 90% avoidances (choosing the correct arm). After exposure of rats to one of the stressors for 60 min, the rats were returned to the home cage; the latency to enter the safe arm was recorded in 6 daily trials that started 1 h after application of stressor. Both stressors significantly prolonged the avoidance latencies for 2 or 3 days in Wistar and Lewis rats, respectively; then the latencies returned to the values obtained before the stress exposure. In Lewis rats, the latencies more increased after IMO+C than after IMO stressor, and the maximal increase in latencies was higher in Lewis rats than in Wistar rats. The latency did not reach the time limit for foot-shock delivery, and the number of correct choices remained unchanged in both strains. The results indicate that the used restraint stressors did not affect the long-term memory; rather a transient impairment of retrieval can be considered. Further, differences in response of Lewis and Wistar rats may be interpreted by different activity of hypothalamic-pituitary-adrenal axis activity in used strains.     

考试应激对唾液皮质醇及SIgA的影响

本研究以某校高二在校６０名男性学生为研究对象，以期末考试为应激源，采用自身对照方法，研究了考试应激对学生唾液中ＳＩｇＡ（分泌型免疫球蛋白Ａ）及皮质醇影响，并对该组学生进行了ＥＰＱ测定，结果表明考试应激期间唾液ＳＩｇＡ值较考前有明显下降，考试期间唾液皮质醇值较考前有明显上升（Ｐ＜０．０１）；Ｎ维度和ＳＩｇＡ下降率及皮质醇上升率呈显著水平相关（Ｐ＜０．０１）。     

N-棕榈酰乙醇胺对慢性束缚应激小鼠焦虑抑郁样行为的影响

目的:采用慢性束缚应激小鼠模型,研究N-棕榈酰乙醇胺(N-palmitoylethanolamide,PEA)对小鼠焦虑抑郁样行为的影响,进一步探讨PEA抗小鼠焦虑抑郁作用的可能机制。方法:小鼠分为正常对照组、模型组、氟西汀(10 mg/kg)组和PEA 2.5、5、10 mg/kg组,每天灌胃给药后30 min,将小鼠(除了正常对照组)放置于有机玻璃管内接受4 h的慢性束缚应激,持续21 d。第22天采用旷场实验和强迫应激实验观察PEA对慢性束缚应激小鼠抑郁样行为的影响;高架十字迷宫实验探讨PEA对慢性束缚应激小鼠焦虑样行为的影响;水迷宫方法分析PEA对慢性束缚应激小鼠学习、记忆、空间定向和认知功能等方面的作用;ELISA方法检测慢性束缚应激小鼠血清促肾上腺皮质激素(adrenocorticotropic hormone,ACTH)、皮质醇(cortisol,CORT)及海马5-羟色胺(5-hydroxytryptamine,5-HT)含量的变化;可见分光光度法检测海马乙酰胆碱酯酶(acetylcholinesterase,ACh E)活性的改变。结果:与模型组相比,在小鼠强迫应激实验中,PEA及氟西汀组小鼠不动时间明显减少;旷场试验中,PEA及氟西汀明显增加小鼠水平移动距离及运动总时间,但只有PEA 10 mg/kg及氟西汀组增加了小鼠直立次数;在高架十字迷宫实验中,PEA及氟西汀明显增加小鼠开臂进入次数、开臂停留时间百分比及在臂总移动距离;在水迷宫实验中,PEA 5、10mg/kg及氟西汀组明显缩短小鼠寻台潜伏期,PEA 10 mg/kg及氟西汀组明显缩短小鼠搜寻距离。与应激模型组比较,PEA 2.5~10 mg/kg及氟西汀显著降低小鼠血清中ACTH水平,PEA 5、10 mg/kg及氟西汀显著降低小鼠血清CORT水平及小鼠肾上腺指数,PEA 10 mg/kg及氟西汀显著增高海马5-HT含量,降低海马ACh E活性,但PEA 2.5和5 mg/kg组海马组织中5-HT含量及ACh E活性则无明显改变。结论:PEA对束缚应激模型小鼠的焦虑及抑郁样行为具有一定的拮抗作用,其具体作用机制可能与调节下丘脑-垂体-肾上腺轴功能、增加海马单胺类递质5-HT水平及参与中枢胆碱系统的调节有关。     

Effect of acute ether or restraint stress on plasma corticotropin-releasing hormone, vasopressin and oxytocin levels in the rat

Ether and restraint stress-induced peripheral plasma corticotropin releasing hormone (CRH), arginine vasopressin (AVP), oxytocin (OXY) and adrenocorticotropin (ACTH) levels were measured by radioimmunoassays. Plasma CRH, AVP, OXY and ACTH rose to approximately twice the level of control rats 2 min after the onset of a 1-min exposure to ether. Plasma CRH rose further 5 min after the onset of ether stress, while plasma AVP and OXY returned to the baseline levels at 5 min. Plasma CRH, OXY and ACTH showed significant elevation 2 min after the onset of restraint stress, while plasma AVP did not show a significant change. Plasma OXY and ACTH rose further 5 min after the onset of restraint stress, whereas plasma CRH returned to baseline levels. CRH and OXY concentrations in the hypothalamic median eminence decreased 5 min after the onset of ether exposure and restraint, while the AVP concentration did not differ from control levels. The results, including the discrepancy between plasma CRH and ACTH 5 min after stress, suggest that CRH in the peripheral plasma is derived from both hypothalamic and extrahypothalamic tissues. The levels of stress-induced CRH in the peripheral plasma were sufficient to stimulate ACTH release. These results suggest that ether and restraint stress elevate plasma CRH shortly after the onset of the stress, and that this elevation in the plasma CRH level is at least partly responsible for stress-induced ACTH secretion.     

Serum levels of IgA1 and IgA2 in children and in patients with IgA deficiency

Serum levels of IgA1 and IgA2 were measured by solid phase radioimmunoassay in samples from 110 children between 3 months and 10 years of age. Both IgA1 and IgA2 were detectable in all samples, and both IgA1 and IgA2 increased with increasing age. The percent of total serum IgA that was IgA2 did not change with age and was the same in samples from children (15.05 +/- 10.2%) as in samples from adults (15.86 +/- 7.98%). The proportion of serum IgA that was IgA2 was much less variable within sibships than within the group at large (P less than 0.005). In the 16 patients with IgA deficiency, the proportion of serum IgA that was IgA1 or IgA2 was highly variable. IgA2 constituted more than 50% of the IgA in 5 patients and less than 7% of the IgA in an additional 5 patients. These findings suggest that regulation of serum concentrations of IgA1 and IgA2 is complex and influenced by genetic factors and probably other unidentified factors.     

Effects of academic examination stress on eating behavior and blood lipid levels

The influence of academic examination stress on eating behavior and lipid profiles and the moderating effect of dietary restraint, trait anxiety, and social support availability was assessed in university students. One hundred and seventy-nine students were divided into exam-stress groups (51 women, 64 men) and control groups (48 women, 16 men) and were assessed at baseline and then within 2 weeks of exams or an equivalent point for the control group. Perceived stress, emotional well-being, and fasting lipid profiles were measured, and dietary information was collected by interview. The exam-stress group reported significant increases in perceived stress and deterioration in emotional well-being at the exam sessions compared with baseline sessions. No general effects of exam stress on food intake were observed, and there was no interaction between stress and dietary restraint. However, students in the exam-stress group with high trait anxiety and low social support showed significant increases in total energy intake between baseline and exam sessions, whereas individuals with low trait anxiety and high social support showed a reduction in energy intake. Students with high trait anxiety and low social support showed increases between baseline and exam sessions in the amount of fat and saturated fat consumed. Women in the exam-stress group taking oral contraceptives showed a significant increase in total cholesterol between baseline and exam sessions. The results are discussed in relation to the effects of naturally occurring episodic stress on health behavior and on lipid profiles. Tessa M. Pollard now at the Department of Anthropology, University of Durham, England.     

Effect of chronic restraint stress on carbohydrate metabolism in rat

There is some evidence suggesting that stress may induce diabetes mellitus; the effects of restraint stress however need to be investigated. The present study investigates the role of chronic restraint stress on carbohydrate metabolism in male rats. The animals of the stressed group (n=8) were exposed to different restraint stressors (1 h twice daily) for 30 days. On days 1, 15 and 30, before stress exposure, the animals were weighed and fasting blood samples were obtained by tail snipping and subsequently oral glucose tolerance tests (OGTT) were carried out. Fasting plasma glucose levels on the 15th day and the plasma glucose concentrations, on the 15th and 30th days of the experiment at 15 and 60 min following OGTT, in the stressed group, were significantly higher as compared to the control group. In the stressed group, fasting plasma insulin levels on the 15th and 30th days of the experiment and the plasma insulin concentrations, on the 15th day at 15 and 60 min after performing OGTT, were significantly lower as compared to the control group. Fasting plasma corticosterone concentrations were significantly increased on the 15th day of the experiment in the stressed rats as compared to the control rats and to concentrations on the 1st day. The weights of the stressed rats on the 15th and 30th experimental days were significantly lower than the controls. In conclusion, chronic restraint stress for 30 days leads to low body weight gain in rats and impairs glucose metabolism perhaps by affecting corticosterone and insulin secretion and by inducing a degree of insulin resistance.     

Effects of restraint stress on the expression of proteins involved in synaptic vesicle exocytosis in the hippocampus

Chronic restraint stress has been associated with induction of morphological changes in the hippocampus. Postsynaptically, these changes include decreased length and branching of apical dendrites from CA3 pyramidal neurons, while presynaptically, depletion and clustering of synaptic vesicles have been observed. However, the molecular correlates of these changes remain poorly defined; while some studies have identified changes in the levels of some presynaptic proteins, none have assessed the coordinate expression of components of the membrane fusion complex, including synaptobrevin, syntaxin, and synaptosomal-associated protein 25 kDa, and their major regulatory molecules synaptotagmin, synaptophysin, and synapsin. Therefore, we undertook to assess the immunoreactivity of these proteins in hippocampal slices obtained from rats subjected to either acute (one 6 h session) or chronic (21 days at 6 h per day) of restraint stress. Specifically, we observed a significant increase in synaptobrevin immunoreactivity in the inner molecular layer of the dentate gyrus (54.2%; P=0.005), the stratum radiatum in the CA1 subfield (55.5%; P=0.007), and a region including the stratum lucidum and the proximal portion of the stratum radiatum in the CA3 subfield (52.7%; P=0.002); we also observed a trend toward increased synaptophysin levels in the stratum lucidum/radiatum of the CA3 subfield (8.0%; P=0.051) following chronic, but not acute, restraint stress. In that synaptobrevin has been associated with replenishment of the "readily-releasable" pool of synaptic vesicles and the efficiency of neurotransmitter release, the present results suggest that stress-induced changes in synaptobrevin may at least in part underlie the previously observed changes in synaptic and neuronal morphology.     

Quantitation of nasal secretory IgA by enzyme-linked immunosorbent assay

Sites at which positive skin-test reactions have been elicited exhibit an accelerated (so-called 'retest') reaction upon local reinjection of the antigen used for primary skin testing. When using a peritoneal cavity inflammation model in guinea pigs, local migration inhibition factor (MIF) release in vivo was studied in both primary and retest reactions to purified protein derivative. Increased retest reactivity could be demonstrated to coincide with an instantaneous and intense local MIF release. Estimation of both the absolute number of the antigen specificity of lymphocytes present in the peritoneal cavity at the time of retesting (170 h after primary testing) showed that the early burst of MIF release is primarily due to nonspecific local retention of increased numbers of lymphocytes.     

Effects of chronic restraint stress and estradiol on open field activity,spatial memory,and monoaminergic neurotransmitters in ovariectomized rats

Twenty-one days of chronic restraint stress impairs male rat performance on the radial arm maze [Luine et al. (1994) Brain Res. 639, 167-170], but enhances female rat performance [Bowman et al. (2001) Brain Res. 904, 279-289]. To assess possible ovarian hormone mechanisms underlying this sexually dimorphic response to stress, we examined chronic stress effects in ovariectomized rats. Ovariectomized rats received Silastic capsule implants containing cholesterol or estradiol and were assigned to a daily restraint stress (21 days, 6 h/day) or non-stress group. Following the stress period, subjects were tested for open field activity and radial arm maze performance. Stress and estradiol treatment affected open field activity. All stressed animals, with or without estradiol treatment, made fewer total outer sector crossings. In contrast, estradiol-treated animals, with or without stress, made more inner sector visits, an indication that estradiol decreased anxious behavior on the open field across time. As measured by the total number of visits required to complete the task, stress did not affect radial arm maze performance in ovariectomized rats, but estradiol-treated animals, with or without stress, performed better than non-treated animals on the radial arm maze. Stressed subjects receiving estradiol showed the best radial arm maze performance. Following killing, tissue samples were obtained from various brain regions known to contribute to learning and memory, and monoamine and metabolite levels were measured. Several changes were observed in response to both stress and estradiol. Most noteworthy, stress treatment decreased homovanillic acid levels in the prefrontal cortex, an effect not previously observed in stressed intact females. Estradiol treatment increased norepinephrine levels in CA3 region of the hippocampus, mitigating stress-dependent changes. Both stress and estradiol decreased dentate gyrus levels of 5-hydroxyindole acetic acid. In summary, the current study provides novel information showing that estradiol alters behavioral and neurochemical responses to stress in ovariectomized rats. Estradiol treatment decreased anxious behavior on the open field and stressed animals receiving estradiol had enhanced radial arm maze performance. In relation to interactions between stress and estradiol on cognition and anxiety, changes in the prefrontal cortex dopaminergic system, dentate gyrus serotonergic system, and norepinephrine levels in the CA3 region appear important. Results show that estradiol may moderate stress effects on cognition and anxiety through both organizational and activation effects.     

Central MHC genes affect IgA levels in the human: reciprocal effects in IgA deficiency and IgA nephropathy

This study investigates the hypothesis that alternative alleles of one or more genes in the central major histocompatibility complex (MHC) predispose carriers to IgA deficiency (IgAD) or IgA Nephropathy (IgAN). Australian caucasian IgAD, IgAN patients, and controls were typed at HLA loci, single nucleotide polymorphisms, and microsatellites in the MHC. Alleles of the D6S273 microsatellite exhibited strong associations with IgAD and IgAN. D6S273*129 and *139 were more frequent in IgAD and less frequent in IgAN patients than controls. The reverse was true for D6S273*133 and *131. Alleles of other microsatellites exhibited weak associations with IgAD or IgAN. D6S273*129 is found on the 65.1 ancestral haplotype [HLA-B14(65),DR1], which has been reported to be increased in IgAD, but the majority of IgAD patients with D6S273*129 did not have other alleles of the haplotype. D6S273*139 is characteristic of the 8.1 ancestral haplotype (HLA-A1,B8,DR3), which was common in IgAD and rare in IgAN patients. Further studies of the 8.1 haplotype in Australian, German and Spanish caucasian subjects revealed that HLA-DR3, in the absence of -B8, is not associated with IgAD. However -B8 is associated with IgAD in the absence of -DR3, consistent with a susceptibility locus in the central MHC. Provisional mapping within this region is discussed.     

Binge-type eating attenuates corticosterone and hypophagic responses to restraint stress

Binge eating has been associated with stress responses. Data in rats suggest that activation of the hypothalamic-pituitary-adrenal (HPA) axis is suppressed by consumption of a high sucrose diet, and is increased with exposure to a high fat diet. Additionally, the choice to consume a highly palatable food following exposure to a stressor results in reduced corticosterone levels. To test the effects of intermittent access to a high sugar/high fat food on stress hormone levels, rats were given either unrestricted (UR) access to a sucrose-vegetable shortening mixture (SVS) or 2 hour SVS access 7 days (7D) or 3 days (3D) per week for 4 weeks. Rats on the UR and 3D schedules consumed significantly more calories per day than did controls with no access to SVS, and the 7D and 3D rats consumed as many SVS calories in the 2 hour access period as did the UR rats with 24 hour access to SVS. After 4 weeks of access to SVS (UR, 7D, and 3D), rats were briefly restrained. Control and UR rats had elevated corticosterone during and following restraint, whereas there were no differences in corticosterone levels of 7D and 3D rats in response to restraint, as compared to baseline. Post-restraint consumption of chow was significantly decreased in all groups, and consumption of SVS was reduced in the UR, but not the 7D and 3D rats. These data demonstrate that intermittent access to SVS dampens the corticosterone response to restraint stress and that stressful events do not induce bingeing in non-bingeing animals with access to a high sucrose/high fat food.