Cardioprotective Effects of Mebudipine in a Rat Model of Doxorubicin-Induced Heart Failure.

Background: Mebudipine, a dihydropyridine calcium-channel blocker (CCB), shows greater time- and voltage-dependent inhibitory effects than nifedipine. Its significant negative chronotropic effects without having considerable negative inotropic properties may make it a suitable candidate for the pharmacotherapy of heart failure (HF). This study aimed to investigate the possible beneficial action of mebudipine in a rat model of HF. Methods: The present study carried out in the Department of Pharmacology at the Iran University of Medical Sciences during the years of 2009-2011. An experimental model of HF was induced in male Wistar rats using doxorubicin (DOX). The rats were divided into five groups with seven animals in each group: normal control group, DOX-induced HF control groups, and treatment groups. The animals were administered DOX for 15 days. A consistent deterioration occurred after a four-week rest period. The animals were then treated with intraperitoneal mebudipine (0.5 mg/kg) and intraperitoneal amlodipine (0.35 mg/kg), as well as an equal volume of distilled water for 15 days. The plasma levels of big endothelin-1 (BET-1), creatine kinase-myocardial band (CK-MB), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT), as well as the clinical status (heart rate and blood pressure), were assessed before and after treatment. Statistical analysis was performed with SPSS software using parametric and nonparametric ANOVA. Results: Mebudipine and amlodipine reversed the increased plasma BET-1 values in the treated animals when compared with the HF control group (0.103 and 0.112 vs 0.231 pg/mL, respectively). The increased plasma levels of AST, ALT, CK-MB, and LDH were also reversed in the HF animals that received mebudipine or amlodipine. Conclusion: The administration of mebudipine to HF animals, akin to amlodipine, palliated the clinical and biochemical signs of the disease in the present study. The abstract was presented in the Iranian Congress of Physiology and Pharmacology as a poster and published in the Scientific Information Database as a supplement (2015; Vol 22).

Evaluation of tissue repair using phytotherapeutic gel from Plectranthus neochilus, Schlechter (boldo-gambá) and Cnidoscolus quercifolius Pohl (favela) in Wistar rats / [Avaliação da reparação tecidual do gel fitoterápico de Plectranthus neochilus, Schlechter (Boldo-gambá) e Cnidoscolus quercifolius Pohl (Favela) em ratos Wistar]

The objective of this study was to investigate the effects of a gel formulation from the association of Plectranthus neochilus and Cnidoscolus quercifolius on tissue repair in cutaneous wounds in rats. A surgical wound was induced in 35 Wistar rats and treated according to group: G1 - commercial phytotherapeutic gel; G2 - Carbopol gel 1%; G3, 4, 5 - gel formulation from Boldo-gambá and Favela (FGBF) at 2.5%, 5%, and 10%, respectively. 1ml of the product was applied topically daily, for 14 days. Macroscopic evaluation of the wound showed inflammation, granulation, and epithelization in all groups. The FGBF 2.5% group showed greater angiogenic potential. There was a significant difference between the surgical area of the wounds treated with FGBF 2.5%, 5%, or 10% compared to the group with the commercial phytotherapeutic gel. On histomorphometry of the skin, there were reepithelization of the epidermis and superficial dermis, longitudinal collagen fibers, fibroblasts, and blood vessels, and in the deeper dermis, fibroblasts, transverse and longitudinal collagen fibers, blood vessels, and inflammatory cells. The 2.5% formulation had the greatest increase in fibroblast proliferation and most intense collagenization on day 14 of treatment.(AU)

Este trabalho objetivou investigar os efeitos de uma formulação em gel da associação da Plectranthus neochilus e da Cnidoscolus quercifolius no processo de reparação tecidual em feridas cutâneas de ratos. Foi induzida uma ferida cirúrgica em 35 ratos Wistar, sendo tratadas de acordo com os grupos: G1 - fitoterápico comercial; G2 - gel de carbopol 1%; G3, G4 e G5 - formulação gel boldo-gambá mais favela (FGBF) 2,5%, 5% e 10%, respectivamente. Aplicou-se 1mL do produto, via tópica, diariamente, durante 14 dias. Na avaliação macroscópica das feridas, verificou-se inflamação, granulação e epitelização em todos os grupos. O grupo FGBF 2,5% apresentou maior potencial angiogênico. Houve diferença significativa entre as áreas cirúrgicas das feridas tratadas com os FGBF 2,5%, 5% ou 10%, comparados ao grupo com o gel fitoterápico comercial. Na histomorfometria da pele, observou-se reepitelização da epiderme e da derme superficial, fibras colágenas longitudinais, fibroblastos e vasos sanguíneos e, na derme profunda, fibroblastos, fibras colágenas transversais e longitudinais, vasos sanguíneos e células inflamatórias. A formulação a 2,5% teve o maior aumento na proliferação de fibroblastos e mais intensa colagenização no dia 14 de tratamento.(AU)

Efeito do extrato de Bidens pilosa L, Mel e pomadas homeopática e alopática na cicatrização de feridas cutâneas de ratos Wistar / [Effect of Bidens pilosa L, Honey extract and homeopathic and allopathic ointments on the healing of skin wounds of Wistar rats]

Cicatrização de ferida é um processo dinâmico, que tem por objetivo restaurar a continuidade do tecido lesionado. No entanto, em alguns casos, é necessário favorecer condições adequadas para viabilizar o processo fisiológico. Neste estudo foram utilizados ratos Wistar, divididos aleatoriamente entre cinco grupos, com 12 animais cada, sendo eles: grupo P (Bidens pilosa L.), grupo mel, grupo Co1 (pomada comercial alopática), grupo Co2 (pomada comercial homeopática) e grupo CT (controle). As lesões foram geradas por incisão com punch de 8mm, sendo tratadas diariamente de forma tópica. Foram eutanasiados quatro animais por grupo, no terceiro, sétimo e 14º dias do experimento, e o material coletado foi armazenado em formalina 10% e encaminhado para processamento histológico. Posteriormente, realizou-se a contagem de leucócitos mononucleares, fibroblastos e neovasos e avaliou-se a arquitetura de fibras colágenas. Os resultados da contagem foram analisados pela ANOVA, seguida pelo teste de Tukey (P<0,05). O modelo experimental proposto neste estudo demonstrou que todos os tratamentos apresentaram potencial cicatrizante, com exceção do mel. A aplicação tópica do creme do extrato de Bidens pilosa L. a 10% apresentou melhor perfil anti-inflamatório; a pomada alopática apresentou boa aderência à superfície da lesão e a pomada homeopática, grande potencial angiogênico, com menor tempo de cicatrização.(AU)

Wound healing is a dynamic process that aims to restore the continuity of injured tissue. However, in some cases it is necessary to favor adequate conditions to enable the physiological process. Wistar rats were randomly divided into 5 groups with 12 animals each, namely: group P (Bidens pilosa L.), group honey, group Co1 (commercial allopathic ointment), group Co2 (commercial homeopathic ointment) and group CT (control). The lesions were generated by an 8mm punch incision and were treated topically daily. Four animals per group were euthanized on the 3rd, 7th and 14th day of the experiment and the collected material was stored in 10% formalin and sent for histological processing, after which mononuclear, fibroblasts and neovascular leukocytes were counted and collagen fiber architecture was evaluated. Counting results were analyzed by ANOVA, followed by Tukey test (p <0.05). The experimental model proposed in this study showed that all treatments had healing potential, except honey. The topical application of 10% Bidens pilosa L. extract cream showed the best anti-inflammatory profile; Allopathic ointment showed good adhesion to the surface of the lesion and homeopathic ointment showed great angiogenic potential with shorter healing time.(AU)

The effect of multivitamin-multimineral supplementation on the health status of inbred Wistar and spontaneously hypertensive rat strains.

The nutraceutical industry has proliferated in recent years, with the most popular form of supplementation being the multivitamin-multimineral (MVMM) supplement. In the animal health sector, supplement use has also expanded. The objective of this study was to determine the effects of MVMM supplementation, beneficial or otherwise, on the general health status of the spontaneously hypertensive rat (SHR) strain, an animal model used in hypertension research. A commercially prepared MVMM supplement was given tri-weekly via oral dosing for 8 weeks to two groups of seven adult female SHR and Wistar rats. Their corresponding control groups were dosed with deionised water only. Systolic and diastolic blood pressure, fasting blood glucose, growth rate and food and water intake were measured weekly. At the end of 8 weeks, the animals were euthanased and a full blood profile, urine sodium to potassium ratio, blood urea nitrogen levels and total plasma cholesterol was measured for all groups. The results indicated that growth rate was higher for the SHR supplemented group. Supplementation also decreased diastolic blood pressure in both Wistar and SHR groups and increased red blood cell count and decreased total cholesterol in the SHR group. No adverse effects on the general health status of the animals were observed. MVMM supplementation may therefore be useful in aiding growth and delaying the onset of hypertension and its effects. It may also assist in the longevity of the breeding stock of SHR rats.

Trans fatty acids modify nutritional parameters and triacylglycerol metabolism in rats: differential effects at recommended and high-fat levels / Los ácidos grasos trans modifican parámetros nutricionales y el metabolismo de triacilglicéridos en ratas: efectos diferenciales a niveles recomendados y elevados de grasa

Introduction: there is still little evidence on the metabolic trans fatty acids (TFA) effects at recommended fat levels. Objective: to investigate the differential TFA effects on some nutritional parameters, TFA retention, and triacylglycerol (TAG) regulation in rats fed recommended and high-fat diets. Methods: male Wistar rats were fed (30 days) diets containing recommended (7%,w/w) or high-fat (20%,w/w) levels, supplemented or not with TFA (C7, C20, TFA7 and TFA20). Results: TFA7 (vs.C7) rats showed an increased body weight associated with higher fat pads and liver and serum TAG. The hypertriacylglyceridaemia was related to a decreased muscle LPL activity, while the higher hepatic TAG content was associated with both an increased SREBP-1c gene expression and ACC activity, and a reduced CPT-Ia gene expression. The TFA20 diet did not potentiate the higher body weight, fat pads and TAG levels induced by the C20 diet. Although the hepatic TAG-secretion rate (TAG-SR) increased by TFA20 vs. C20, the same triacylglyceridaemia was associated with a compensatory increase of the adipose tissue LPL activity. The attenuated hepatic TAG accretion in TFA20 was related to an increase of TAG-SR and to a lower increase of SREBP-1c and SCD1 mRNA expressions, paralleled to a relative decrease of SCD1 index and ACC activity. Discussion and conclusion: TFA alters nutritional parameters and lipid metabolism in rats. However, different responses to the TFA on TAG levels and their regulation were observed between rats fed recommended and high-fat diets. These divergences might be related to different tissue TFA retentions and rumenic acid bioconversion (AU)

Introducción: existen escasas evidencias sobre los efectos metabólicos de los AGT a niveles recomendados de grasa. Objetivo: investigar los efectos diferenciales de los ácidos grasos trans (TFA) sobre parámetros nutricionales, retención de TFA y regulación de triacilglicéridos (TAG) en ratas alimentadas con niveles recomendados o elevados de grasa. Métodos: ratas macho Wistar fueron alimentadas (30 días) con dietas que contenían un 7% o 20% de grasas suplementadas o no con TFA (C7-C20-TFA7-TFA20). Resultados: TFA7 (vs. C7) incrementó el peso corporal asociado a mayores panículos adiposos y TAG. La hipertriacilgliceridemia fue relacionada con una menor actividad LPL muscular, y el incrementado TAG hepático con una elevada expresión génica de SREBP-1c y actividad ACC, y reducida expresión génica de CPT-Ia. Los TFA no potenciaron los elevados pesos corporales, los panículos adiposos y los TAG inducidos por C20. Aunque la secreción hepática de TAG (TAG-SR) incrementó en TFA20 vs. C20, la similar triacilgliceridemia fue asociada a un compensatorio incremento de la actividad LPL en tejido adiposo. La atenuada acumulación hepática de TAG en TFA20 estuvo relacionada con una incrementada TAG-SR y un menor incremento de la expresión génica de SREBP-1c y SCD1, paralela a un relativo descenso del índice SCD1 y de la actividad ACC. Discusión y conclusión: los TFA alteran los parámetros nutricionales y lipídicos en ratas. Sin embargo, diferentes respuestas sobre los niveles y regulación de los TAG por los TFA fueron observadas entre ratas alimentadas con niveles recomendados y elevados de grasa dietaria. Estas divergencias pueden estar relacionadas con diferentes retenciones de TFA y su bioconversión a ácido ruménico (AU)

Femoral biomechanic and microtomography from male ratssubmitted to dietary restriction supplemented with sucrose

Food restriction reduces body weight and influence bone mass and also is correlated with bone mineraldensity (BMD). Mechanisms have been proposed for the loss of BMD after body weight reduction, includingreduced energy intake. Growing 8 wk-old Wistar male rats were randomly divided into Control and Calorierestriction associated with sucrose 30% (CRS). These animals were subjected to intermittent food restrictionduring 8 weeks and had free access to tap water and sucrose30% in distilled water. The rats were euthanizedat the end of week 8, blood collected from abdominal aorta artery, femurs cleaned of adherent soft tissues,scanned using dual energy X-ray absorptiometry, structural and material properties determined by three-pointbending testing in the mid-diaphyseal region, bone surface tested in a microhardness tester and microstructurewas assessed in a microcomputer tomography. In CRS animals body weight decreased significantly relative tothe Control animals. There was a clear option for high-sucrose beverage in CRS animals. No difference wasobserved in biochemical, densitometric and biomechanical analyzes. Results from micro CT showed onlysignificant difference in connectivity of trabecular bone. It has been suggested that rats submitted to foodrestriction consumed sugar not because of its inherent palatability, but in order to alter their macronutrientbalance and animals need to meet energy demands in high-sucrose.

Normal variations in the morphology of auditory brainstem response (ABR) waveforms: a study in Wistar rats.

Auditory brainstem evoked responses (ABR) have been used for decades to assess auditory function. Surprisingly, despite the fact that rats are one of the most widely used experimental models in hearing, there have been no studies that have characterized in detail the normal morphological variations that occur in ABR waves. Therefore, the goal of this study was to characterize the patterns of ABR waves in rats to establish baseline criteria that could be used to identify abnormalities. Rats were stimulated with pure tone sounds at different frequencies and ABR waves were classified based on morphology. The most definitive finding was that, unlike what is observed in human ABRs, wave II of the rat ABR was the most prominent. Additionally, wave III was the smallest and, in many cases, was not apparent at low frequencies. Wave III was frequently involved in the formation of complexes, often appearing as a small wave or adjoining primarily wave IV. Complexes were common at low and medium frequencies and rare at high frequencies. These results indicate that knowledge of the different wave patterns in normal rats is fundamental to understanding how the wave morphology changes in pathological conditions that could lead to hearing impairment.

Avaliação da atividade cicatrizante do óleo de pequi (Caryocar coriaceum Wittm) em feridas cutâneas produzidas experimentalmente em ratos / Evaluation of the healing activity of pequi (Caryocar coriaceum Wittm) oil in cutaneous wounds induced experimentally in rats

O objetivo deste estudo foi demonstrar os efeitos do tratamento tópico do creme à base de óleo de pequi (Caryocar coriaceum Wittm) utilizando 40 ratos (Rattus norvegicus albinus) da linhagem Wistar, machos, com 60 dias de idade. Esses foram divididos em dois grupos: I) composto por 20 ratos com feridas cutâneas tratados com aplicação tópica do creme base com 10% de óleo de pequi; II) com o mesmo número de animais que receberam a aplicação tópica do creme base sem o óleo de pequi. Após antissepsia e anestesia local foi produzida cirurgicamente ferida circular de 1 cm de diâmetro na região dorso lombar. As lesões cutâneas foram avaliadas sob o aspecto clínico, morfométrica e histológico no 3o, 7o, 14o e 21o dias pós-operatório. No grupo tratado com creme à base de óleo de pequi houve aceleração na evolução do processo cicatricial. As feridas dos animais desse grupo apresentaram redução significativa a partir do décimo quarto dia pós-operatório, bem como foram verificados nesse período achados histológicos característicos da etapa final do processo de cicatrização tais como: acentuada quantidade de fibroblastos, fibras colágenas e completo processo de reepitelização, enquanto que as feridas do grupo controle necessitaram de mais tempo para resolução do processo cicatricial.

The main objective of this study was to demonstrate the effects of topical treatment with ointment containing pequi oil (Caryocar coriaceum Wittm), using 40 male 60-day-old mice (Rattus norvegicus albinus) from the Wistar line. These were divided into two groups: I) composed by 20 mice with cutaneous wounds treated by topical application of the ointment based on 10% pequi oil; II) the same number of mice, receiving the topical application of ointment without pequi oil. After antisepsis and local anesthesia, round 1-cm-diameter wounds were made on the lower back region. The wounds were evaluated in regard to clinical, morphometric and histological aspects on the 3rd, 7th, 14th and 21st postoperative days. The group treated with the pequi ointment presented acceleration in the healing process. The animals' wounds of this group showed a meaningful reduction from the 14th postoperative day, when histological characteristics from the ending of the healing process were noted, such as a large amount of fibroblasts, collagen fibers and a complete process of reepithelialization, while the wounds of the control group needed more time for the healing process.

Carbohydrate-to-fat ratio affects food intake and body weight in Wistar rats.

The aim of the study was to evaluate the impact of carbohydrate-to-fat ratio on body weight and appetite regulation in Wistar rats. Twenty-four Wistar rats were randomized to three dietary groups (n = 8): normal carbohydrate diet (NC), low-carbohydrate diet (LC) and high-carbohydrate diet (HC) for 12 weeks. Body weight and food intake were recorded. Circulating leptin and insulin levels were measured by radioimmunoassay method. The expression levels of leptin receptor, insulin receptor, orexin, neuropeptide Y (NPY), agouti-related protein (AgRP) and melanocortin-4 receptor (MC-4R) in the hypothalamus were also measured by realtime polymerase chain reaction (PCR). In the LC group, food intake reduced while body weight increased significantly compared with the NC and HC groups. Plasma leptin levels increased in the LC (18.5 +/- 8.2 ng/mL) group compared with the NC (8.6 +/- 3.8 ng/mL, P < 0.001) and HC (6.6 +/- 1.9 ng/mL, P < 0.001) groups. Realtime reverse transcription-PCR revealed a decrease in the hypothalamic expression level of only leptin receptor in the LC (0.764, 0.471-4.648 copy/mL) and HC (0.357, 0.129-0.781 copy/mL) groups compared with the NC (1.323, 0.616-2.392 copy/mL; P = 0.01) group, and that there was no significant change in those of insulin receptor, AgRP, Orexin, NPY and MC-4R. Low-carbohydrate, high-fat diet raised body weight, which led to a rising of circulating leptin levels and a reduced expression of leptin receptor in the hypothalamus.

Comparison of cortical epileptic afterdischarges in immature genetic absence epilepsy WAG/Rij rats with those in two other strains (ACI and Wistar).

The aim of this study was to examine the development of cortical epileptic afterdischarges (ADs) in genetic absence epilepsy WAG/Rij rats, and to compare them with two strains with minimal incidence of spike-and-wave (SW) episodes (ACI and Wistar). Epileptic ADs were elicited by stimulation of sensorimotor cortex in 12-, 18-, and 25-day-old rats of the three strains. The threshold current intensities were established for movements accompanying stimulation, for ADs of the SW type and accompanying clonic seizures and for transition into limbic type of ADs (characterized by behavioral automatisms). Individual groups were formed by 7-12 rats. There were no differences among the three strains in the thresholds for elicitation of stimulation-bound movements. In contrast, WAG/Rij and ACI rats exhibited easier elicitation of SW ADs than Wistar rats at the age of 18 and 25 days. There was no difference among the three strains in transition into the limbic type of ADs in 18- and 25-day-old rats. Lower thresholds for SW ADs in 18- and 25-day-old WAG/Rij and ACI rats in comparison with Wistar rats are in agreement with our data from adult animals as well as with development of pharmacologically induced models of absence seizures. The failure to find a specific difference between WAG/Rij rats and the other two strains might indicate a difference in generation of SW episodes and SW cortical AD.

Efeito da suplementação de beta-caroteno na pressão arterial de ratos / Effect of beta-carotene supplementation on the blood pressure of rats

OBJETIVO: Investigar se a suplementação com doses suprafisiológicas de beta-caroteno exerce efeito positivo no controle da hipertensão arterial, e detectar possíveis efeitos adversos dessa suplementação. MÉTODOS: Ratos espontaneamente hipertensos (n=12) e normotensos (n=12) com 20 semanas, foram submetidos a um período basal de 10 dias, e subdivididos em 4 grupos de 6 animais, suplementados com beta-caroteno em três diferentes doses: 2,5mg, 3,75mg e 5,0mg por animal, via gavagem orogástrica diária, durante 14 dias para cada dose, intercaladas por um período de wash-out de 7 dias; os grupos controle receberam apenas o veículo (óleo de coco). Foram ainda submetidos à avaliação ectoscópica para possível detecção de efeitos tóxicos ou interação entre nutrientes, e à análise dos parâmetros biológicos; a pressão sistólica foi aferida por pletismografia duas vezes na semana, em dias alternados. Após o período de suplementação os animais foram sacrificados, e tiveram o peso do fígado determinado pelo método de Scherle. RESULTADOS: A administração de beta-caroteno não levou a alterações dos parâmetros biológicos dos animais, assim como não foi detectado efeito tóxico. Quanto à pressão arterial sistólica, as duas linhagens apresentaram redução significante (p<0,05), sendo a maior redução observada durante administração da terceira dose. O peso médio do fígado foi de 7,25 (desvio-padrão 3,2) gramas, e a relação média do peso do órgão/média do peso corpóreo igual a 0,0192 para o grupo dos hipertensos. CONCLUSÃO: A suplementação de beta-caroteno tem efeito positivo tanto no controle quanto na prevenção da hipertensão arterial de ratos. A relação peso do fígado/peso corpóreo apresentou-se dentro dos padrões de normalidade.

OBJECTIVE: To investigate if supplementation with supraphysiological doses of beta-carotene has a positive effect on controlling hypertension and detect possible adverse effects of this supplementation. METHODS: 20-week-old spontaneously hypertensive rats (n=12) and normotensive rats (n=12) were submitted to a basal period of 10 days, then divided into 4 groups of 6 animals and supplemented daily by orogastric gavage with beta-carotene in 3 different doses: 2.5mg, 3.75mg and 5.0mg/animal during 14 days for each dose that was inserted by a seven day wash-out period; control groups received only coconut oil. Animals were submitted to ectoscopic evaluation to detect possible toxic effects or interaction between nutrients and analysis of biological parameters; systolic blood pressure was measured by plethysmography twice a week on alternate days; after the supplementation period, animals were killed and their livers weighed by the Scherle method. RESULTS: Administration of beta-carotene did not alter the animals' biological parameters or cause any toxic effects. Regarding systolic blood pressure, both lineages showed significant results (p<0.05), with the highest dose presenting the best results. The average liver weight was 7.25 (3.2 standard-deviation) grams, and the relationship between the average liver weight and body weight was 0.0192 for the hypertensive group. CONCLUSION: Beta-carotene supplementation was effective in controlling and preventing hypertension in rats. The relationship between liver weight and body weight was normal.

Effects of soybean fortification on protein quality of tortilla-based diets produced from regular and quality protein maize.

The physiological development of laboratory rats fed with a typical indigenous tortilla diet was studied for two generations. The experiment compared casein control diet and five different types of diets: (1) a diet of tortillas obtained from fresh masa (FM); (2) regular tortillas produced from enriched dry masa flour containing vitamins B1, B2, niacin, folic acid, and the microminerals iron and zinc (REDMF); (3) tortillas produced from enriched dry masa flour fortified with 6% defatted soybean meal (FEDMF); (4) tortillas produced from enriched quality protein maize flour (EQPM); and (5) and, tortillas produced from enriched quality protein maize flour fortified with 3% defatted soybean meal (FEQPM). The growth of rats fed FEDMF and FEQPM diets was significantly higher (P < 0.05) in both generations than their counterparts fed EQPM, REDMF, or FM diet. Animals fed quality protein maize (QPM) tortilla had the highest protein digestibility, but the FEQPM and FEDMF diets had the highest biological value (BV), net protein utilization (NPU), and protein-digestibility-corrected EAA scores (PDCEAAS). The difference among treatments was more evident in the second-generation rats. The pregnancy rate, number of newborns/litter, litter weight, and newborn survival rate was also higher for rats fed FEDMF, EQPM, and FEQPM diets than their counterparts fed REDMF and FM.

Neonatal development of projections to the basolateral amygdala from prefrontal and thalamic structures in rat.

Recently an animal model for neurodevelopmental disorders has been developed. In this model the effects of an early neonatal [postnatal day 7 (Pd7)] basolateral amygdala lesion are compared with the effects of a lesion later in life (Pd21). Early amygdala damage results in enduring behavioral disturbances that become more manifest after puberty. These disturbances were not present in animals lesioned at Pd21. Accordingly it was postulated that the early damage may affect the neuroanatomical and neurochemical organization and functioning of other brain structures. To obtain information on the innervation of the amygdala during normal development, we used the retrograde tracer fluoro-gold. From neonatal day 7 onward (studied until Pd19), retrogradely labeled cells were present in the caudal and rostral thalamus, the substantia innominata, and the prefrontal but not the caudal cortex. Development of the topography of the projecting cells differed substantially for the thalamic regions and substantia innominata vs. the cortical regions. In thalamic regions and substantia innominata, no changes were observed during the studied period (Pd7-Pd9). In the prefrontal cortex, the number of labeled cells increased (from Pd7 to Pd13), the topography of the location of the cells changed from unilateral to bilaminar (from Pd9 to Pd13), and the number of subareas in which the cells were present increased (from Pd7 to Pd13). In the caudal cortex, relatively few cells were present up to Pd15. From Pd17 onward, a bilaminar topography of the location of the cells was observed. These data provide information on the circuitry that may be involved in the aberrant neurodevelopment of neonatally amygdala-lesioned rats, which has been proposed as an animal model for neurodevelopmental psychopathological disorders.

Immunohistochemical localization of candidates for vesicular glutamate transporters in the rat brain.

Vesicular glutamate transporter 1 (VGluT1) is one of the best markers for glutamatergic neurons, because it accumulates transmitter glutamate into synaptic vesicles. Differentiation-associated Na(+)-dependent inorganic phosphate cotransporter (DNPI) shows 82% amino acid identity to VGluT1, and is another candidate for vesicular glutamate transporters. Here, we report the immunocytochemical localization of DNPI and compare it with that of VGluT1 in the adult rat brain. Both DNPI and VGluT1 immunoreactivities were found mostly in neuropil, presumably in axon terminals, throughout the brain. In the telencephalic regions, intense DNPI immunoreactivity was observed in the glomeruli of the olfactory bulb, layer IV of the neocortex, granular layer of the dentate gyrus, presubiculum, and postsubiculum. In contrast, VGluT1 immunoreactivity was intense in the olfactory tubercle, layers I-III of the neocortex, piriform cortex, entorhinal cortex, hippocampus, dentate gyrus, and subiculum. In the thalamic nuclei, DNPI-immunoreactive terminal-like profiles were much larger than VGluT1-immunoreactive ones, suggesting that DNPI immunoreactivity was subcortical in origin. DNPI immunoreactivity was much more intense than VGluT1 immunoreactivity in many brainstem and spinal cord regions, except the pontine nuclei, interpeduncular nucleus, cochlear nuclei, and external cuneate nucleus. In the molecular layer of the cerebellar cortex, climbing-like fibers showed intense DNPI immunoreactivity, whereas neuropil contained dense VGluT1-immnoreactive deposits. Both DNPI and VGluT1 immunoreactivities were observed as mossy fiber terminal-like profiles in the cerebellar granular layer. DNPI and VGluT1 immunoreactivities appeared associated with synaptic vesicles in the axon terminals forming asymmetric synapses in several regions examined electron microscopically. The present results indicate that DNPI and VGluT1 are used by different neural components in most, if not all, brain regions, suggesting the complementary functions of DNPI and VGluT1.

Re-examination of the thalamostriatal projections in the rat with retrograde tracers.

Topographical arrangements of thalamostriatal projection neurons was examined in the rat by the retrograde tract-tracing method. After injecting Fluoro-Gold (FG) and/or cholera toxin beta-subunit (CTB) in different regions of the caudate-putamen (CPu), distribution of retrogradely labeled neurons was observed in the thalamus. The main findings were as follows: (1) Retrogradely labeled neurons were seen in the midline-intralaminar thalamic nuclei in all rats examined in the present study. Neurons in the ventral lateral and posterior thalamic nuclear groups were also labeled in the rats which were injected with the tracer into the dorsal part of Cpu, but not in the rats which were injected with the tracer into the nucleus accumbens (Acb) and its adjavent regions in the ventromedial part of the Cpu. (2) Topographical organization was observed in the projections from the midline-intralaminar thalamic nuclei to the CPu. After the tracer injection into the dorsal part of the CPu or the ventral part of the CPu (including the Acb), labeled neurons in the midline-intralaminar thalamic nuclei were distributed predominantly in the lateral part of the intralaminar nuclei or the midline nuclei, respectively. On the other hand, after the tracer injection into the medial or the lateral part of the CPu, labeled neurons in the midline-intralaminar nuclei were distributed mainly in the dorsal or the ventral part of these nuclei, respectively. (3) Topographical organization was also observed in the thalamostriatal projections from the ventral and Pos. After the tracer injection into the rostral part of the CPu, labeled neurons were distributed mainly in the rostral part of the ventral nuclear group. On the other hand, after the tracer injection into the caudal part of the CPu, labeled neurons were distributed mainly in the caudal part of the ventral nuclear group, as well as in the posterior nuclear group.

Neonatal development of projections from the basolateral amygdala to prefrontal, striatal, and thalamic structures in the rat.

Recently, an animal model for neurodevelopmental disorders has been developed. In this model, the effects of an early neonatal (postnatal day 7 [Pd 7]) basolateral amygdala lesion are compared with the effects of a lesion later in life (Pd 21). The reported data indicate that amygdala damage at a specific point early in life results in enduring behavioral disturbances that become more manifest after puberty, for example, only an early lesion resulted in a disruption of the prepulse inhibition, which is also observed in people suffering from schizophrenia. Accordingly, it was postulated that the early damage may affect the neuroanatomic and neurochemical organization and functioning of other brain structures. This was studied by use of the anterograde tracers biotinylated dextran amine and Phaseolus vulgaris-leucoagglutinin. At neonatal days 7, 9, 11, 13, and 26, amygdaloid fibers were in particular present in the mediodorsal thalamus (MDT), nucleus accumbens (Acb), and prefrontal cortex (PFC). The development of the topography of the amygdaloid innervation, however, differed markedly for the MDT and Acb compared with the PFC. For the MDT and Acb, no major changes in innervation were observed between Pd 7 and Pd 26, whereas the innervation of the PFC reorganized from a neonatal diffuse (Pd 7 and 9) to a restricted pattern (Pd 11, 13, and 26). In addition, the innervation changed to an adult-like bilaminar pattern. These data provide information on the circuitry that may be involved in the aberrant neurodevelopment of neonatally amygdala-lesioned rats, which have been proposed as an animal model for neurodevelopmental psychopathological disorders.

Alteration of body composition in rats: effect of organic chromium and L-carnitine.

A growth trial was carried out to test the effect of organic, trivalent chromium and L-carnitine on the body composition of growing rats. At the same time, an evaluation of different measurement methods (weight of epididymal fat pad, adipocyte morphometry, total body electrical conductivity) was performed. Outbred Wistar rats of 30 days of age were fed diets of different (0, 10 and 20%) protein level. The diets were supplemented with 4 mg/kg Cr as chromium nicotinate, and 100 mg/kg L-carnitine. The experimental feeding lasted 15 days, after a 5-day-long adjustment period. It was found that Cr addition increased feed intake. Both treatments caused changes in body composition, increasing fat and protein deposition. Organic chromium had no effect at either protein level, while L-carnitine improved the protein retention only at an optimum (20%) protein supply. No statistically significant correlation was found between total body electrical conductivity (TOBEC) and body composition, which could be attributed to the great individual differences. A close correlation was found among total body fat percentage, weight of epididymal fat pad and the adipocyte surface. The data suggest that there is an interaction between dietary protein supply and the effect of repartitioning agents.

The effect of lecithin supplementation on the biochemical profile and morphological changes in the liver of rats fed different animal fats.

Sixty-four Wistar rats were divided into 8 equal groups and kept for 36 days in individual boxes. Three of the groups were given full synthetic diets containing various animal fats: beef tallow, pork fat or fish oil. A control group was fed the diets without the fat. The other four groups were fed the same diets with lecithin supplementation. At the end of experiment, sections taken from the liver were stained with haematoxylin eosin and Sudan III to indicate fat infiltration. Liver enzyme levels, total bilirubin, albumin and two products of lipid metabolism were measured in serum from all the animals. The addition of lecithin to the diets did not influence the level of enzymes in the serum except in rats fed the diet containing beef tallow. A relationship between the type of diet, lecithin supplementation and the total cholesterol concentration in serum was observed. The concentration of HDL-cholesterol was only influenced by lecithin supplementation and that of triglycerides by the type of fat in the diet. The addition of lecithin to the diet was associated with proliferation of Kupffer cells, and an increased number of binuclear cells. Fatty degeneration of hepatocytes was less pronounced in all groups following lecithin supplementation. Lecithin supplementation of the diet did not elicit any pathological lesions and may be considered as a hepatocyte protector. This favourable effect of lecithin was most marked in the group of rats fed the fish oil.

Cortical facilitatory action on centralis lateralis thalamic activity during the development of carrageenin-produced inflammation

In order to understand the neuronal mechanisms involved in acute and chronic pain, we studied the thalamic and cortical control action, which allows the suppression of the neuronal responses to noxious stimulation. As an experimental pain model we used carrageenin injected in the paw of male Wistar rats. The tonic facilitatory cortical control on centralis lateralis thalamic nuclei (CL) activity is described at different times after carrgeenin-produced inflammation. Simultaneous extracellular unit recordings were carried out at CL and medial prefrontal cortex (PCx) cells in anesthetized male Wistar rats. The PCx control was tested by blocking in a transient and reversible manner, using the cortical spreading depression (CSD). Carrageenin injection (1 percent; 0.2 ml) into the plantar surface of the right hind paw, and the influence of Lidocaine (2 percent; 0.2 ml) applied in the inflamed paw, was tested on unit activity in PCx and CL cells. Thalamic cells recorded in acute and subacute stages (24-72 h aftercarrageenin administration) were activated by tactile, light pressure and joint movement stimulation yielded before the injection. After carrageenin, the thalamic cells displayed spontaneous high frequency burst discharges, also presenting a progressive and significant increase (p < 0.001, ANOVA test) of their spontaneous firing when rate when compared with control cell activity. Lidocaine reduced the enhanced activity induced by carrageenin in thalamic neurones (p < 0.001, Student t test). In PCx neurones were also recorded in acute and subacute stages. Cortical cells from acute and subacute group were activated by nociceptive and non-nociceptives stimulation. In acute stage, cortical cells increased their firing rate after carrageenin and we could not observe modifications upon their firing rate due to Lidocaine. The CSD blocked all cortical activity in acute subacute stages. During the CSDs, overall thalamic activity was suppressed in neurones from acute (91 percent) and subacute (87 percent) stages. The blockage was observed when the propagated weve produced by CSD arrived into the medial prefrontal cortex. the CSD also suppressed the PCx and the CL noxious responses evoked by pressure in the receptive field. This study show the tonic facilitatory control of the PCx upon intralaminar thalamic noxious responses, during acute and subsacute stages of carrageenin produced inflammation. In the literature, it has been proposed that the CL thalamic...