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Long-Evans Rats (Long-Evan + rat)
Kinds of Long-Evans Rats Selected AbstractsEarly Social Isolation in Male Long-Evans Rats Alters Both Appetitive and Consummatory Behaviors Expressed During Operant Ethanol Self-AdministrationALCOHOLISM, Issue 2 2009Brian A. McCool Background:, Postweaning social isolation in rats produces profound and long-lasting cognitive and behavioral deficits in adult animals. Importantly, this housing manipulation alters sensitivity to a number of drugs of abuse including ethanol. However, most studies with ethanol have utilized continuous or limited home-cage access to examine interactions between juvenile social experience and drinking. More recently, social isolation was shown to increased ethanol responding in a "dipper" model of self-administration (Deehan et al., 2007). In the current study, we utilize a "sipper" operant self-administration model to distinguish the effects of isolation rearing on ethanol seeking- and drinking-related behaviors. Methods:, Postweaning juvenile male Long-Evans rats were placed into 2 housing groups for 6 weeks: one group consisted of individually housed animals; the second group was housed 4 animals per cage. Following the isolation period, anxiety-like behavior was assessed to confirm the efficacy of the isolation procedure. In some animals, ethanol drinking in the home cage was assessed using a continuous access, 2-bottle choice paradigm. All animals were then individually housed and trained to lever-press for a sipper tube containing either an ethanol solution or a sucrose solution. Results:, Postweaning social isolation increased the expression of anxiety-like behavior in the elevated plus maze but not the light-dark box. Ethanol consumption was also increased during continuous home-cage access with the 2-bottle choice paradigm. During operant self-administration, isolation housing increased the response rate and increased ethanol consumption but did not alter responding for or consumption of sucrose. The housing manipulation did not change the total number of lever responses during extinction sessions. Paired-pulse inhibition deficits that are characteristic of juvenile isolation remained intact after prolonged experience with sucrose self-administration. Discussion:, The effects of postweaning social isolation on ethanol drinking in the home cage are also manifest during operant self-administration. Importantly, these alterations in adult operant self-administration are ethanol-specific. [source] PRECLINICAL STUDY: Conditioned cues and yohimbine induce reinstatement of beer and near-beer seeking in Long-Evans ratsADDICTION BIOLOGY, Issue 2 2009Jemma K. Richards ABSTRACT Alcohol use disorders (AUDs) impact millions of individuals, yet there are few effective treatments. One major problem in treating AUDs is the high rate of relapse to drinking often induced by stress and/or anxiety states. Although beer accounts for over 81% of all alcohol consumed in hazardous amounts in the United States, the use of beer in pre-clinical research has been limited. It has been shown that rats will self-administer beer and near-beer using a standard operant self-administration paradigm; however, there have been few studies examining reinstatement of beer and near-beer seeking. We have determined that reward-associated cues and/or yohimbine will induce reinstatement of beer and near-beer seeking in a similar manner to that seen for 10% ethanol and sucrose seeking using standard operant self-administration and reinstatement paradigms. We show that rats will self-administer beer, near-beer and 4.5% ethanol using an operant self-administration paradigm and both conditioned cues, and yohimbine will induce reinstatement of beer, near-beer and 4.5% ethanol seeking in previously extinguished animals. This demonstrates that both environmental cues and yohimbine-stress will reinstate beer and near-beer seeking, as previously shown for both 10% ethanol and sucrose seeking. [source] Sexually dimorphic effects of hippocampal cholinergic deafferentation in ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2004Zachariah Jonasson Abstract To determine whether the basal forebrain-hippocampal cholinergic system supports sexually dimorphic functionality, male and female Long-Evans rats were given either selective medial septum/vertical limb of the diagonal band (MS/VDB) cholinergic lesions using the neurotoxin 192 IgG-saporin or a control surgery and then postoperatively tested in a set of standard spatial learning tasks in the Morris water maze. Lesions were highly specific and effective as confirmed by both choline acetyltransferase/parvalbumin immunostaining and acetylcholinesterase histochemistry. Female controls performed worse than male controls in place learning and MS/VDB lesions failed to impair spatial learning in male rats, both consistent with previous findings. In female rats, MS/VDB cholinergic lesions facilitated spatial reference learning. A subsequent test of learning strategy in the water maze revealed a female bias for a response, relative to a spatial, strategy; MS/VDB cholinergic lesions enhanced the use of a spatial strategy in both sexes, but only significantly so in males. Together, these results indicate a sexually dimorphic function associated with MS/VDB-hippocampal cholinergic inputs. In female rats, these neurons appear to support sex-specific spatial learning processes. [source] Selective lesions of basal forebrain cholinergic neurons produce anterograde and retrograde deficits in a social transmission of food preference task in ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2002Anna Vale-Martínez Abstract We examined the performance of Long-Evans rats with 192 IgG-saporin lesions of the medial septum/vertical limb of the diagonal band (MS/VDB) or nucleus basalis magnocellularis/substantia innominata (NBM/SI), which removed cholinergic projections mainly to hippocampus or neocortex, respectively. We studied the effects of these lesions on anterograde and retrograde memory for a natural form of hippocampal-dependent associative memory, the social transmission of food preference. In a study of anterograde memory, MS/VDB lesions did not affect the immediate, 24-h or 3-week retention of the task. In contrast, NBM/SI lesions severely impaired immediate and 24-h retention. In a study of retrograde memory in which rats acquired the food preference 5 days or 1 day before surgery and they were tested 10,11 days after surgery, MS/VDB-lesioned rats showed striking memory deficits for the preference acquired at a long delay (5 days) before surgery, although all lesioned rats exhibited poorer retention on both retest sessions than on their pretest performance. Subsequent testing of new anterograde learning in these rats revealed no disrupting effects of lesions on a standard two-choice test. When rats were administered a three-choice test, in which the target food was presented along with two more options, NBM/SI-lesioned rats were somewhat impaired on a 24-h retention test. These results provide evidence that NBM/SI and MS/VDB cholinergic neurons are differentially involved in a social memory task that uses olfactory cues, suggesting a role for these neurons in acquisition and consolidation/retrieval of nonspatial declarative memory. [source] Plasticity of perisynaptic astroglia during synaptogenesis in the mature rat hippocampusGLIA, Issue 1 2007Mark R. Witcher Abstract Astroglia are integral components of synapse formation and maturation during development. Less is known about how astroglia might influence synaptogenesis in the mature brain. Preparation of mature hippocampal slices results in synapse loss followed by recuperative synaptogenesis during subsequent maintenance in vitro. Hence, this model system was used to discern whether perisynaptic astroglial processes are similarly plastic, associating more or less with recently formed synapses in mature brain slices. Perisynaptic astroglia was quantified through serial section electron microscopy in perfusion-fixed or sliced hippocampus from adult male Long-Evans rats that were 65,75 days old. Fewer synapses had perisynaptic astroglia in the recovered hippocampal slices (42.4% ± 3.4%) than in the intact hippocampus (62.2% ± 2.6%), yet synapses were larger when perisynaptic astroglia was present (0.055 ± 0.003 ,m2) than when it was absent (0.036 ± 0.004 ,m2) in both conditions. Importantly, the length of the synaptic perimeter surrounded by perisynaptic astroglia and the distance between neighboring synapses was not proportional to synapse size. Instead, larger synapses had longer astroglia-free perimeters where substances could escape from or enter into the synaptic clefts. Thus, smaller presumably newer synapses as well as established larger synapses have equal access to extracellular glutamate and secreted astroglial factors, which may facilitate recuperative synaptogenesis. These findings suggest that as synapses enlarge and release more neurotransmitter, they attract astroglial processes to a discrete portion of their perimeters, further enhancing synaptic efficacy without limiting the potential for cross talk with neighboring synapses in the mature rat hippocampus. © 2006 Wiley-Liss, Inc. [source] Post-training reversible inactivation of hippocampus reveals interference between memory systemsHIPPOCAMPUS, Issue 2 2002Jason P. Schroeder Abstract A post-training reversible lesion technique was used to examine the effects of neural inactivation of the dorsal hippocampus on place and response learning. Male Long-Evans rats trained in one of two versions of a water plus-maze task received post-training intra-hippocampal infusions of the local anesthetic drug bupivacaine (0.75% solution, 0.5 ,l), or saline. Post-training intra-hippocampal infusions of bupivacaine attenuated acquisition of the place task and enhanced acquisition of the response task. Delayed (2-h) post-training infusions of bupivacaine did not affect retention in either task. The findings demonstrate (1) enhanced learning after reversible hippocampal lesions that is independent of treatment influences on non-mnemonic factors, and (2) inactivation of the dorsal hippocampus during the post-training memory consolidation period is sufficient to enhance response learning. Hippocampus 2002;12:280,284. © 2002 Wiley-Liss, Inc. [source] Individual differences in spatial memory among aged rats are related to hippocampal PKC, immunoreactivityHIPPOCAMPUS, Issue 2 2002Paul J. Colombo Abstract We reported previously that the extent of spatial memory impairment among aged rats was correlated positively with levels of protein kinase C, in hippocampal homogenates measured by quantitative Western blotting (Colombo et al., 1997). In the current study, immunocytochemistry was used to test whether the relationship between elevated PKC, and memory impairment among aged rats could be localized further within regions of the hippocampus. Six- and 24-month-old male Long-Evans rats were first trained in the water maze on a standard place-learning task and then trained 2 weeks later on a transfer task designed for rapid acquisition. In comparison with young rats, aged rats with impaired spatial memory had increased PKC,-immunoreactivity (PKC,-ir) in CA1 of the hippocampus, but not the dentate gyrus. In addition, PKC,-ir in CA1 was correlated positively with spatial memory impairment among aged rats on the standard place-learning and the transfer training tasks. The current results are consistent with our previous report of PKC, in hippocampal homogenates, and show further that the relationships between PKC,-ir and memory impairments among aged rats are most evident in area CA1. Thus age-related impairments of spatial memory, as well as deficits in the flexible use of previously acquired information, may result from dysregulation of PKC,. Hippocampus 2002;12:285,289. © 2002 Wiley-Liss, Inc. [source] Variations in Maternal Behaviour are Associated with Differences in Oxytocin Receptor Levels in the RatJOURNAL OF NEUROENDOCRINOLOGY, Issue 12 2000D. D. Francis Abstract Female Long-Evans rats exhibit stable individual differences in maternal behaviours such as pup licking/grooming and arched-back nursing posture (LG-ABN). These variations in maternal behaviour are accompanied by differences in lactation-induced increases in oxytocin receptor levels in brain regions known to mediate the expression of maternal care in this species (i.e. the bed nucleus of the stria terminalis, the medial preoptic area and the lateral septum). Oxytocin receptor levels in the central nucleus of the amygdala were significantly higher in high compared to low LG-ABN females regardless of reproductive status. These findings suggest that individual differences in maternal behaviour may be directly related to variations in oxytocin receptor expression. [source] Exercise Neuroprotection in a Rat Model of Binge Alcohol ConsumptionALCOHOLISM, Issue 3 2010J. Leigh Leasure Background:, Excessive alcohol intake produces structural and functional deficits in corticolimbic pathways that are thought to underlie cognitive deficits in the alcohol use disorders (AUDs). Animal models of binge alcohol administration support the direct link of high levels of alcohol consumption and neurotoxicity in the hippocampus and surrounding cortex. In contrast, voluntary wheel running enhances hippocampal neurogenesis and generally promotes the health of neurons. Methods:, We investigated whether voluntary exercise prior to binge alcohol exposure could protect against alcohol-induced cell loss. Female Long-Evans rats exercised voluntarily for 14 days before undergoing 4 days of binge alcohol consumption. Brains were harvested immediately after the last dose of alcohol and examined for various histological markers of neurodegeneration, including both cell death (FluoroJade B) and cell birth (Ki67) markers. Results:, Rats that exercised prior to binge exposure were significantly less behaviorally intoxicated, which was not a result of enhanced hepatic metabolism. Rats that exercised prior to binge alcohol consumption had reduced loss of dentate gyrus granule cells and fewer FluoroJade B positive cells in the dentate gyrus and associated entorhinal-perirhinal cortex compared to nonexercisers. However, exercise did not protect against cell death in the piriform cortex nor protect against alcohol-induced decreases in cell proliferation, evidenced by a similar alcohol-induced reduction in Ki67 labeled cells between exercise and sedentary rats. Conclusions:, We conclude that exercise can reduce behavioral sensitivity to ethanol intoxication and protect vulnerable brain areas from alcohol-induced cell death. Exercise neuroprotection of alcohol-induced brain damage has important implications in understanding the neurobiology of the AUDs as well as in developing novel treatment strategies. [source] Effects of Pregnanolone and Dehydroepiandrosterone on Ethanol Intake in Rats Administered Ethanol or Saline during AdolescenceALCOHOLISM, Issue 7 2009Olga V. Gurkovskaya Background:, Adolescent alcohol use may contribute to long-term changes in the receptors and neuroactive steroids that may mediate its effects and to subsequent alcohol abuse and dependence as an adult. Therefore, in this study, ethanol preference and intake as an adult were examined after adolescent ethanol or saline administration. In addition, ethanol intake in the same groups was examined after administration of 2 neuroactive steroids with modulatory effects at GABAA receptors. Methods:, Two groups of male Long-Evans rats were administered 15 intraperitoneal (i.p.) injections of either ethanol (2 g/kg, 20% v/v) or saline between postnatal days 35 and 63. Starting on postnatal day 75, both groups were trained to consume 10% ethanol using a saccharin-fading procedure, and ethanol intake and preference were measured after a series of manipulations involving food deprivation, changes in the duration of access to ethanol, and changes in the concentrations of ethanol presented. Following these manipulations, pregnanolone (1 to 10 mg/kg) and dehydroepiandrosterone (DHEA, 1 to 100 mg/kg) were administered prior to preference sessions with an 18% ethanol solution. Results:, Adult ethanol preference and intake did not differ significantly in subjects treated with either saline or ethanol as adolescents during training, the substitution of other ethanol concentrations (3.2 to 32%), ad-lib feeding, or moderate food deprivation. Pregnanolone administration altered the intake of both adolescent-treated groups after the first injection of 3.2 mg/kg and after repeated injections with 10 mg/kg, a dose that produced sedation. In contrast, multiple doses of DHEA consistently decreased intake of an 18% ethanol concentration in both groups after repeated injections and 3 doses of DHEA (10, 32, and 56 mg/kg) administered with various ethanol concentrations dose-dependently shifted the ethanol-concentration curves for the volume and dosage of ethanol consumed downward. Conclusions:, These results indicate that chronic intermittent ethanol (CIE) administration of 2 g/kg during adolescence did not alter preference or overall consumption of ethanol in outbred rats trained to drink ethanol as an adult under the conditions tested, and that DHEA may be more effective than pregnanolone at significantly decreasing ethanol consumption. [source] Early Social Isolation in Male Long-Evans Rats Alters Both Appetitive and Consummatory Behaviors Expressed During Operant Ethanol Self-AdministrationALCOHOLISM, Issue 2 2009Brian A. McCool Background:, Postweaning social isolation in rats produces profound and long-lasting cognitive and behavioral deficits in adult animals. Importantly, this housing manipulation alters sensitivity to a number of drugs of abuse including ethanol. However, most studies with ethanol have utilized continuous or limited home-cage access to examine interactions between juvenile social experience and drinking. More recently, social isolation was shown to increased ethanol responding in a "dipper" model of self-administration (Deehan et al., 2007). In the current study, we utilize a "sipper" operant self-administration model to distinguish the effects of isolation rearing on ethanol seeking- and drinking-related behaviors. Methods:, Postweaning juvenile male Long-Evans rats were placed into 2 housing groups for 6 weeks: one group consisted of individually housed animals; the second group was housed 4 animals per cage. Following the isolation period, anxiety-like behavior was assessed to confirm the efficacy of the isolation procedure. In some animals, ethanol drinking in the home cage was assessed using a continuous access, 2-bottle choice paradigm. All animals were then individually housed and trained to lever-press for a sipper tube containing either an ethanol solution or a sucrose solution. Results:, Postweaning social isolation increased the expression of anxiety-like behavior in the elevated plus maze but not the light-dark box. Ethanol consumption was also increased during continuous home-cage access with the 2-bottle choice paradigm. During operant self-administration, isolation housing increased the response rate and increased ethanol consumption but did not alter responding for or consumption of sucrose. The housing manipulation did not change the total number of lever responses during extinction sessions. Paired-pulse inhibition deficits that are characteristic of juvenile isolation remained intact after prolonged experience with sucrose self-administration. Discussion:, The effects of postweaning social isolation on ethanol drinking in the home cage are also manifest during operant self-administration. Importantly, these alterations in adult operant self-administration are ethanol-specific. [source] Effects of sleep deprivation on wound healingJOURNAL OF SLEEP RESEARCH, Issue 3 2005L. MOSTAGHIMI Summary Sleep deprivation is widely regarded as a stressor and has been shown to have significant effects on host defences. Severely sleep-deprived rats develop lesions on their paws and tails, suggesting possible deficits in the healing process. The purpose of this study was to assess the impact of rapid eye-movement (REM) sleep deprivation (RSD) on wound healing in a rat model. Male dark-hooded Long-Evans rats, 2,4 months old, were subjected to dorsal application of two sterile punch biopsies, each 3.5 mm in size. Biopsies were performed either immediately before or immediately after 5 days of sleep deprivation. Wound healing in REM sleep-deprived animals was compared with home cage control and yoked control animals. RSD did not produce differences in the rate of healing, regardless of the timing of the biopsy punch. RSD does not appear to have significant effects on wound healing and thus appears to act differently from other types of stressors on wound healing. [source] Coregulation of Ethanol Discrimination by the Nucleus Accumbens and AmygdalaALCOHOLISM, Issue 3 2003Joyce Besheer Background: Activation of GABAA receptors in the amygdala or nucleus accumbens produces discriminative stimulus effects that substitute fully for those of systemically administered ethanol. This study was conducted to determine if GABAA receptors in the amygdala and nucleus accumbens interactively modulate ethanol discrimination. Methods: Male Long-Evans rats were trained to discriminate between intraperitoneal injections of ethanol (1 g/kg) and saline on a 2-lever drug discrimination task. The rats were then surgically implanted with bilateral injection cannulae aimed at the nucleus accumbens and the amygdala. Results: Infusion of the GABAA agonist muscimol in the nucleus accumbens resulted in full substitution for systemically administered ethanol. Concurrent infusion of the GABAA antagonist bicuculline in the amygdala shifted the muscimol substitution curve in the nucleus accumbens 10-fold to the right. Conclusions: These results indicate that blockade of GABAA receptors in the amygdala significantly reduces the potency of the GABAA agonist in the nucleus accumbens. This suggests that the ethanol-like stimulus effects of GABAA receptor activation in the nucleus accumbens are modulated by GABAA receptor activity in the amygdala. These data support the hypothesis that the addictive stimulus properties of alcohol are mediated by GABAergic transmission in a neural circuit involving the amygdala and nucleus accumbens. [source] Role of Acetaldehyde in the Discriminative Stimulus Effects of EthanolALCOHOLISM, Issue 6 2002Etienne Quertemont Background: Acetaldehyde has been suggested to mediate some of the effects of ethanol. Acetaldehyde can be produced by the enzyme catalase within the brain after ethanol administration. The catalase inhibitor 3-amino-1,2,4-triazole (AT) reduces the production of acetaldehyde, and AT administration can reduce a number of ethanol-induced behavioral effects; this suggests the involvement of acetaldehyde in these behaviors. However, a role for acetaldehyde in mediating the discriminative stimulus effects of ethanol remains unclear. Methods: The contribution of acetaldehyde to the discriminative stimulus effects of ethanol was investigated by use of a two-lever drug discrimination paradigm with food reinforcement. Male Long-Evans rats were trained to discriminate water from either 1.0 or 2.0 g/kg ethanol. Stimulus substitution tests were conducted with ethanol (0,2.5 g/kg by gavage) and acetaldehyde (0,300 mg/kg intraperitoneally). A cumulative dose-response procedure was then used to investigate the effects of pretreatments with AT (0.5 and 1.0 g/kg intraperitoneally) on ethanol discrimination. Results: Acetaldehyde up to doses that decreased response rates (300 mg/kg) did not substitute for the discriminative stimulus effects of 1.0 or 2.0 g/kg ethanol. In addition, AT pretreatment did not affect the dose-response curves for ethanol discrimination. Conclusions: These results show that exogenous acetaldehyde administration does not produce discriminative stimulus effects that are similar to those of ethanol. Also, pretreatment with the catalase inhibitor did not affect the dose-response curve for ethanol discrimination, and this suggests that endogenously produced acetaldehyde does not contribute to the discriminative stimulus effects of ethanol. Together these results suggest that acetaldehyde does not mediate the discriminative stimulus effects of 1.0 to 2.0 g/kg ethanol. [source] Chlorpyrifos-Induced Hypothermia and Vasodilation in the Tail of the Rat: Blockade by Scopolamine,BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 1 2000Christopher J. Gordon Organophosphate pesticides such as chlorpyrifos reduce core temperature (Tc) in laboratory rodents. The mechanism(s) responsible for the chlorpyrifos-induced hypothermia are not well known. This study assessed the role of a key effector for thermoregulation in the rat, vasomotor control of heat loss from the tail, and its possible cholinergic control during chlorpyrifos-induced hypothermia. Tc and motor activity were monitored by telemetry in female Long-Evans rats maintained at an ambient temperature (Ta) of 25°. Tail skin temperature (Tsk(t)) was measured hourly. Rats were dosed with chlorpyrifos (0 or 25 mg/kg orally). Two hr later the rats were dosed with saline or scopolamine (1.0 mg/kg intraperitoneally). Two hr after chlorpyrifos treatment there was a marked elevation in Tsk(t) concomitant with a 0.5° reduction in Tc. Scopolamine administered to control rats led to a marked elevation in Tc with little change in Tsk(t). Rats treated with chlorpyrifos and administered scopolamine underwent a marked vasoconstriction and elevation in Tc. Vasodilation of the tail is an important thermoeffector to reduce Tc during the acute stages of chlorpyrifos exposure. The blockade of the response by scopolamine suggests that the hypothermic and vasodilatory response to chlorpyrifos is mediated via a cholinergic muscarinic pathway in the CNS. [source] 2121: Sustained neuroprotection after a single intravitreal injection of PGJ2 in a rodent model of NAIONACTA OPHTHALMOLOGICA, Issue 2010V TOUITOU Purpose Prostaglandin-J2 (PGJ2) has been proposed as a potential neuroprotective agent. We wanted to evaluate the toxicity/efficacy of a single intravitreal (IVT) injection of PGJ2 in a rodent model of nonarteritic anterior ischemic optic neuropathy (NAION). Methods We used the laser-activated rose Bengal induction method to produce AION in Long-Evans rats. We evaluated IVT-PGJ2 retinal and ON toxicity. Following induction, PGJ2 was IVT-injected in the treatment-group. IVT phosphate-buffered-saline (PBS) was used as control. Functional studies (VEP) were performed at baseline and at 7days post-treatment. Structural studies included immunohistochemical (IHC), electron microscopic (EM) analysis of the optic nerve (ON), and stereologic analysis of retinal ganglion cell (RGC) numbers at30 day 30. Results Toxicity: IVT PGJ2 (5 eyes) did not induce any significant functional/structural changes in the retina or ON of treated animals compared with animals injected with PBS (5 eyes) 30 days post-injection. Efficacy: After a single IVT-injection, day7 VEPs in the PGJ2-treatment group (n=7) had amplitudes 103.6% of baseline, whereas the PBS-treated group (n=6) had VEPs that were 42.4% of the baseline. 30days post-stroke, EM of ON from the treatment-group demonstrated significant preservation of axons and decreased demyelination. Stereological RGCcounts confirmed significant (p<0.04) RGC preservation in PGJ2-treated animals (1462.6 cells/µm2) compared w the stroke+PBS group (1156.5 cells/µm2). Conclusion A single IVT of PGJ2 preserves RGCs and their axons, and provides sustained neuroprotection for at least 1 month following initial ischemic event. [source] Folic acid supplementation on red kidney bean-induced diarrhoea and enteric bacterial translocation into mesenteric lymph nodes in rats: a pilot studyACTA PAEDIATRICA, Issue 1 2002R Shoda Deaths following childhood diarrhoea, a major health problem in developing countries, are often associated with malnutrition and septicaemic complications. Folic acid has been used in the treatment of acute and chronic diarrhoea in the tropics. Using a rat model, we evaluated the protective effect of large doses of folic acid on diarrhoea, small intestinal bacterial overgrowth and translocation of enteric bacteria into mesenteric lymph nodes induced by a raw red kidney bean-based diet containing lectin (phytohemagglutinin). Long-Evans rats in 2 groups of 5 each (60 g to 70 g in weight, 28 d old) were used. All 10 rats, individually kept in metabolic cages, received a raw red kidney bean-based diet for 10 d, and 5 of them also received a daily folic acid supplement (160 ,g/g feed) both during and for 10 d before the experiment. The faecal weight was measured and a quantitative aerobic bacterial culture of the small intestinal mucosal scrapings and of the mesenteric lymph nodes was made. Folic acid supplementation did not reduce faecal output nor did it prevent loss of body weight associated with lectin-induced diarrhoea. However, the mean total count of enteric bacteria translocated to the mesenteric lymph nodes was significantly reduced in the supplemented rats (1.27 ± 0.61 vs 2.66 ± 0.84, p= 0.028) and a trend towards reduced bacterial count in the small intestinal mucosal scrapings (0.40 ± 0.89 vs 1.42 ± 1.31, p= 0.16) was documented. A significant positive correlation was also seen between the bacterial count in the jejunal mucosal scrapings and in the mesenteric lymph nodes. Conclusion: Although large-dose folic acid supplementation did not prevent diarrhoea and malnutrition induced by a lectin-based diet, it substantially reduced the count of enteric bacteria translocated into the mesenteric lymph nodes and showed a trend towards a reduction in indigenous bacteria adhering to jejunal mucosa. These findings could be of relevance in the prevention of septicaemic complications following many clinical conditions, including diarrhoea with malnutrition in children known to have bacteraemic and septicaemic complications. [source] | |||||||||||||