Role of zinc in female reproduction.

Zinc is a critical component in a number of conserved processes that regulate female germ cell growth, fertility, and pregnancy. During follicle development, a sufficient intracellular concentration of zinc in the oocyte maintains meiotic arrest at prophase I until the germ cell is ready to undergo maturation. An adequate supply of zinc is necessary for the oocyte to form a fertilization-competent egg as dietary zinc deficiency or chelation of zinc disrupts maturation and reduces the oocyte quality. Following sperm fusion to the egg to initiate the acrosomal reaction, a quick release of zinc, known as the zinc spark, induces egg activation in addition to facilitating zona pellucida hardening and reducing sperm motility to prevent polyspermy. Symmetric division, proliferation, and differentiation of the preimplantation embryo rely on zinc availability, both during the oocyte development and post-fertilization. Further, the fetal contribution to the placenta, fetal limb growth, and neural tube development are hindered in females challenged with zinc deficiency during pregnancy. In this review, we discuss the role of zinc in germ cell development, fertilization, and pregnancy with a focus on recent studies in mammalian females. We further detail the fundamental zinc-mediated reproductive processes that have only been explored in non-mammalian species and speculate on the role of zinc in similar mechanisms of female mammals. The evidence collected over the last decade highlights the necessity of zinc for normal fertility and healthy pregnancy outcomes, which suggests zinc supplementation should be considered for reproductive age women at risk of zinc deficiency.

Is rat a good model for assessment of particulate-based taste-masked formulations?

Recently there has been an increased interest to develop specialised dosage forms that are better suited to specific patient populations, such as paediatrics and geriatrics. In these patient populations the acceptability of the oral dosage form can be paramount to the products success. However, many Active Pharmaceutical Ingredients (APIs) are known to cause an aversive taste response. One way to increase the acceptability and to enhance the palatability of the formulation is to design coated taste-masked particulate-based dosage forms. The masking of poorly tasting drugs with physical barriers such as polymer coatings can be utilised to prevent the release of drug within the oral cavity, thus preventing a taste response. However, currently, there are few assessment tools and models available to test the efficiency of these particulate-based taste-masked formulations. The rat brief access taste aversion model has been shown to be useful in assessment of taste for liquid dosage forms. However, the applicability of the rat model for particulate-based taste masked formulations is yet to be assessed. It is not understood whether dissolution, solubility and thus exposure of the drug to taste receptors would be the same in rat and human. Therefore, rat saliva must be compared to human saliva to determine the likelihood that drug release would be similar within the oral cavity for both species. In this study rat saliva was characterised for parameters known to be important for drug dissolution, such as pH, buffer capacity, surface tension, and viscosity. Subsequently dissolution of model bitter tasting compounds, sildenafil citrate and efavirenz, in rat saliva was compared to dissolution in human saliva. For all parameters characterised and for the dissolution of both drugs in rat saliva, a substantial difference was observed when compared to human saliva. This discrepancy in saliva parameters and dissolution of model drugs suggests that preclinical taste evaluation of particulate-based taste-masked formulations suggests rat is not a good model for predicting taste of solid dosage forms or undissolved drug where dissolution is required. Alternative preclinical in vivo models in other species, or improved biorelevant in vitro models should be considered instead.

Eccentric resistance training and ß-hydroxy-ß-methylbutyrate free acid affects muscle PGC-1α expression and serum irisin, nesfatin-1 and resistin in rats.

The hypothalamus controls metabolism and feeding behaviour via several signals with other tissues. Exercise and supplements can change hypothalamic signalling pathways, so the present study investigated the influence of eccentric resistance training and ß-hydroxy-ß-methylbutyrate free acid supplementation on PGC-1α expression, serum irisin, nesfatin-1 and resistin concentrations. Thirty-two male rats (8 weeks old, 200±17 g body mass) were randomly allocated to control, ß-hydroxy-ß-methylbutyrate free acid supplementation (HMB), eccentric resistance training (ERT), and ß-hydroxy-ß-methylbutyrate free acid supplementation plus eccentric resistance training (HMB+ERT) groups. Training groups undertook eccentric resistance training (6 weeks, 3 times a week) and supplement groups consumed ß-hydroxy-ß-methylbutyrate free acid (HMB-FA) orally (76 mg kg-1 day-1). Twenty-four hours after the last training session, serum and triceps brachii muscle samples were collected and sent to the laboratory for analysis. Two-way ANOVA and Pearson correlation were employed (significance level: P<0.05). The results showed that eccentric resistance training increases skeletal muscle PGC-1α gene expression, as well as serum levels of irisin and nesfatin-1 (P=0.001). Eccentric resistance training decreased the serum concentration of resistin (P=0.001). HMB-FA supplementation increased skeletal muscle PGC-1α gene expression (P=0.002), as well as the serum concentration of irisin and nesfatin-1 (P=0.001), but decreased the serum concentration of resistin (P=0.001). Significant correlations were observed between PGC-1α gene expression and serum concentrations of irisin, nesfatin-1 and resistin. HMB-FA supplementation with eccentric resistance training may induce crosstalk between peptide release from other tissues and increases maximal muscle strength. The combination of the two interventions had a more substantial effect than each in isolation.

Maternal Dietary Supplementation with Oligofructose-Enriched Inulin in Gestating/Lactating Rats Preserves Maternal Bone and Improves Bone Microarchitecture in Their Offspring.

Nutrition during pregnancy and lactation could exert a key role not only on maternal bone, but also could influence the skeletal development of the offspring. This study was performed in rats to assess the relationship between maternal dietary intake of prebiotic oligofructose-enriched inulin and its role in bone turnover during gestation and lactation, as well as its effect on offspring peak bone mass/architecture during early adulthood. Rat dams were fed either with standard rodent diet (CC group), calcium-fortified diet (Ca group), or prebiotic oligofructose-enriched inulin supplemented diet (Pre group), during the second half of gestation and lactation. Bone mineral density (BMD) and content (BMC), as well as micro-structure of dams and offspring at different stages were analysed. Dams in the Pre group had significantly higher trabecular thickness (Tb.Th), trabecular bone volume fraction (BV/TV) and smaller specific bone surface (BS/BV) of the tibia in comparison with CC dams. The Pre group offspring during early adulthood had an increase of the lumbar vertebra BMD when compared with offspring of CC and Ca groups. The Pre group offspring also showed significant increase versus CC in cancellous and cortical structural parameters of the lumbar vertebra 4 such as Tb.Th, cortical BMD and decreased BS/BV. The results indicate that oligofructose-enriched inulin supplementation can be considered as a plausible nutritional option for protecting against maternal bone loss during gestation and lactation preventing bone fragility and for optimizing peak bone mass and architecture of the offspring in order to increase bone strength.

Rat aorta as a pharmacological tool for in vitro and in vivo studies.

Rat aorta assay provides a low cost and rapid platform, especially for preclinical in vivo models. The signaling pathways of the analog on the vessels could be evaluated separately on the endothelium or smooth muscle cells by rings of the rat aorta in vitro. The rat aorta is used for angiogenesis modeling to integrate the benefits of the both in vivo and in vitro models. These explain the importance and usage of rat aorta in researches. Furthermore, about 4503 articles have been published with the key word "rat aorta" in title or abstract from 1955 until the end of 2013 in Medline. In this review, these articles were organized into two main categories: in vivo and in vitro studies. The in vitro section focused on the rat aorta model, as a tool for evaluate the mechanism of vasodilation, vasoconstriction and angiogenesis. In the in vivo section, the most important usage of this tissue was evaluated. Also, the vasotonic signaling pathways in the vessel are explained briefly and some rat aorta applications in vitro and in vivo have been discussed.

Safety assessment and behavioral effects of Solanum guaraniticum leaf extract in rats

ABSTRACT Solanum guaraniticum is a medicinal plant traditionally used to treat gastric and liver diseases. However, there is no documented evidence corroborating its safety. The present study evaluated the potential toxicity of S. guaraniticum leaf extract after acute administration in rats. Single doses of the extract (1.250, 2.500, and 5.000 mg/kg) were administered by gavage, and the rats were then monitored for 48 h and/or 14 days. Mortality, acute signs of toxicity, and general activity in the open field test were assessed as well as hematological and biochemical parameters, enzymatic activity (δ-aminolevulinate dehydratase and acetylcholinesterase), and oxidative stress parameters (lipid peroxidation level, non-protein thiol content, tissue catalase activity, and serum ferrous reducing power). Phytochemical analysis was also performed by HPLC. The results showed that extract administration produced no deaths (LD50 > 5,000 mg/kg), and no significant adverse effects regarding food consumption, body weight gain, gross pathology, or other parameters. However, the open field tests showed a decrease in spontaneous activity (crossing and rearing) mainly at 48 h after treatment. The results suggest that S. guaraniticum extract is not acutely toxic, but causes alterations in central nervous system activity.

RESUMO Solanum guaraniticum é uma planta medicinal tradicionalmente usada para tratar doenças gástricas e hepáticas. Porém, não há evidências documentadas sobre sua segurança. O presente estudo avaliou a toxicidade do extrato das folhas de S. guaraniticum após administração aguda em ratos. Doses únicas do extrato (1.250, 2.500 and 5.000 mg/kg) foram administradas por gavagem e os animais foram monitorados por 48 h ou 14 dias. Mortalidade, sinais de toxicidade aguda e atividade geral, através do teste de campo aberto, foram analisados, assim como parâmetros hematológicos e bioquímicos, atividades enzimáticas (δ-aminolevulinato desidratase e acetilcolinesterase) e parâmetros de estresse oxidativo (nível de peroxidação lipídica, conteúdo de tióis não protéicos, atividade da catalase em tecidos e poder redutor em soro). A análise fitoquímica também foi realizada por HPLC. Os resultados mostraram que a administração do extrato não provoca mortes (LD50>5.000 mg/kg) ou efeitos adversos significativos com relação ao consumo de comida, ganho de peso corporal, análise patológica, entre outros. Entretanto, o teste de campo aberto mostrou uma diminuição na atividade espontânea geral (cruzamentos e levantadas), principalmente em 48 h após o tratamento. Portanto, nossos resultados sugerem que o extrato de S. guaraniticum não é agudamente tóxico, mas causa alterações na atividade do sistema nervoso central.

Influência de dieta imunomoduladora na cicatrização cutânea em ratos / Influence of immunonutritional supplementation on skin wound healing in rats

INTRODUÇÃO: O processo de cicatrização é imediato e dinâmico, com o objetivo de restaurar a continuidade anatômica e funcional, e devem existir condições para esse processo, o que inclui um estado nutricional adequado. Dentre as fórmulas de suplementação existentes, as imunomoduladoras têm sido implicadas na melhora do processo cicatricial e das condições clínicas dos pacientes tratados. Foi avaliada a influência da dieta imunomoduladora (Impact®) sobre diferentes variáveis do processo de cicatrização cutânea. MÉTODO: Ratos adultos e nutridos foram divididos aleatoriamente em quatro grupos, a serem suplementados com a dieta em estudo e com a dieta controle. Dois grupos receberam as respectivas dietas apenas pré-operatoriamente e os outros dois grupos as receberam no perioperatório. Os ratos foram submetidos a três tipos de lesões cutâneas. Foram avaliados os seguintes aspectos: evolução dos pesos, evolução das áreas cruentas, tensiometria das feridas incisionais, taxas de reepitelização e parâmetros histológicos. RESULTADOS: Não houve diferença na evolução dos pesos. Houve melhores índices de fechamento de feridas excisionais nos grupos suplementados com Impact®, a partir do quinto dia de pós-operatório (p=0,02). Os grupos suplementados com a dieta em estudo obtiveram melhores resultados em tensiometria (p = 0,03), taxas de reepitelização (0,04), contagem diferencial de células (p<0,001) e quantidade de colágeno total (p<0,001). CONCLUSÕES: A dieta em estudo (Impact®) promove melhores taxas de fechamento de feridas cruentas, reepitelização mais rápida, cicatrizes com maior resistência tênsil e maiores quantidades de colágeno total nas feridas. Não houve diferença em nenhum dos parâmetros analisados em comparação dos grupos suplementados com Impact® pré e perioperatoriamente.

INTRODUCTION: The wound healing process is immediate and dynamic in order to restore anatomical and functional continuity, and there must be conditions for this process, which include a normal nutritional state. Among the existing supplemental formulas, immuno-enhancing diets have been proposed to improve the wound healing process and patients' clinical conditions. The influence of an immunomodulating diet (Impact®) on different variables of the skin healing process was evaluated. METHOD: Healthy adult rats were randomly divided into four groups of diet supplementation or control. Two groups received their diets only pre-operatively while the other two groups received theirs perioperatively. Rats were subjected to three types of skin lesions. We evaluated the following aspects: changes in weight, development of raw areas, tensiometry of incisional wounds, re-epithelialization rates, and histological parameters. RESULTS: There was no difference in weight changes. There was better closing rates of excisional wounds in groups supplemented with Impact® beginning on the fifth day after surgery (p = 0.02). The groups receiving the dietary supplements obtained the best results in tensiometry (p = 0.03), re-epithelialization rates (p = 0.04), differential cell counts (p < 0.001), and total amount of collagen (p < 0.001). CONCLUSIONS: The study diet (Impact®) promoted better closure rates of raw wounds, faster re-epithelialization, scars with a greater tensile strength, and greater amounts of total collagen in wounds. There was no difference in any of the parameters analyzed compared with the groups supplemented with Impact® pre- and perioperatively.

Avaliação histomorfométrica do efeito do extrato aquoso de urucum (norbixina) no processo de cicatrização de feridas cutâneas em ratos / Histomorphometric evaluation of the effects of the aqueous extract of annatto (norbixin) on wound skin healing in rats

A norbixina é um carotenóide dicarboxílico hidrofílico presente no pericarpo das sementes do urucuzeiro (Bixa orellana L.). O urucum é comumente utilizado na indústria alimentícia e cosmética como corante natural. O objetivo deste trabalho foi avaliar o processo de reparo cicatricial de feridas cutâneas abertas de ratos tratadas com extrato aquoso de urucum contendo 2,5% de norbixina através de análise histomorfométrica. Para tanto, realizou-se feridas cutâneas no dorso de 32 ratos Wistar machos. Estas foram tratadas com extrato de urucum (grupo experimental, n = 16) e solução salina 0,9% (grupo controle, n = 16). Aos 3, 7, 14 e 21 dias após realização do procedimento cirúrgico, os animais foram sacrificados. Os preparados histológicos obtidos foram submetidos à técnica de coloração pela Hematoxilina-Eosina (H.E.) para contagem de células inflamatórias e de fibroblastos; corados pelo azul de toluidina 1% para contagem dos mastócitos e com picrossirius-red para avaliação das fibras colágenas totais. As imagens histológicas destas lâminas foram capturadas por câmera digital acoplada ao microscópio óptico, sob foco fixo e clareza de campo, obtendo-se 10 campos por lâmina com aumento final de 400X. As fotomicrografias foram avaliadas através do software ImageJ. Os resultados obtidos foram submetidos ao teste t de student sendo o valor de p considerado significativo para p< 0,05. O tratamento tópico com extrato de urucum utilizado aumentou o infiltrado inflamatório durante o 3º, 14º e 21º dia pós-operatório. O grupo tratado apresentou maior densidade vascular quando comparado ao controle a partir do 7º e menor quantidade de fibroblastos até o 14º dia pós-cirúrgico. Conclui-se que o extrato de urucum contendo 2,5% de norbixina não é inócuo aos tecidos cutâneos e possui efeitos pró-inflamatórios e pró-angiogênicos durante o processo de reparo tecidual cutâneo em ratos, interferindo no processo fisiológico de cicatrização.

Norbixin is a dicarboxylic water-soluble carotenoid present in the pericarp of the achiote (Bixa orellana L.) seed. Annatto is commonly used by the food and cosmetic industries as a natural pigment. The aim of this study was to evaluate the healing process of open dermal wounds of rats treated with an aqueous solution of annatto containing 2.5% of norbixin carried out by histomorphometric analysis. For this end, cutaneous wounds were made on the back of 32 male Wistar rats. The wounds were treated with annatto solution (experimental group, n = 16) and saline solution 0.9% (control group, n = 16). At 3, 7, 14 and 21 days after the surgical procedure, the animals were sacrificed. After histological preparation, the histological material was submitted to the staining technique with hematoxylin-eosin for the counting of inflammatory cells and fibroblasts, with toluidine blue 1% for mast cell counting and with picrosirius red for the total collagen fibers. The images of those histological slides were captured by a digital camera connected to an optical microscope, with fixed focal length and clear field; 10 fields were captured from each slide with final zoom of 400X. The photomicrographs were analyzed by the ImageJ software. The results were submitted to the Student's t-test and the value of p < 0.05 was considered as relevant. The topical treatment with the annatto solution increased the inflammatory infiltrate during the 3rd, 14th and 21st days after surgery. The experimental group presented increased vascular density compared to the control group after the 7th day and a smaller amount of fibroblasts up to the 14th day after surgery. We concluded that the annatto solution containing 2.5% of norbixin is not innocuous to skin tissues and has proinflammatory and proangiogenic effects during the process of skin wound healing in rats, interfering in the physiological healing process.

Sexual metabolic differences in the rat limbic brain.

BACKGROUND: There is actually limited evidence about the influence of estrogens on neuronal energy metabolism or functional cerebral asymmetry. In order to evaluate this relationship, eight male and sixteen female adult Wistar rats, divided into estrus and diestrus phase, were used to measure basal neuronal metabolic activity in some of the structures involved in the Papez circuit, using cytochrome c oxidase (C.O.) histochemistry. METHOD: We used C.O. histochemistry because cytochrome oxidase activity can be considered as a reliable endogenous marker of neuronal activity. RESULTS: We found higher C.O. activity levels in diestrus as compared to estrus and male groups in the prefrontal cortex and thalamus. Conversely, neuronal oxidative metabolism was significantly higher in estrus than in diestrus and male groups in the dorsal and ventral hippocampus (CA1 and CA3) and in the mammillary bodies. However, no hemispheric functional lateralization was found in estrus, diestrus or male groups by C.O. activity. CONCLUSIONS: These results suggest a modulatory effect of estrogens on neuronal oxidative metabolism.

Excess of methyl donor in the perinatal period reduces postnatal leptin secretion in rat and interacts with the effect of protein content in diet.

Methionine, folic acid, betaine and choline interact in the one-carbon metabolism which provides methyl groups for methylation reactions. An optimal intake of these nutrients during pregnancy is required for successful completion of fetal development and evidence is growing that they could be involved in metabolic long-term programming. However, the biological pathways involved in the action of these nutrients are still poorly known. This study investigated the interaction between methyl donors and protein content in maternal diet during the preconceptual, pregnancy and lactation periods and the consequences on the rat offspring in the short and long term. Methyl donor supplementation reduced leptin secretion in offspring, whereas insulin levels were mostly affected by protein restriction. The joint effect of protein restriction and methyl donor excess strongly impaired postnatal growth in both gender and long term weight gain in male offspring only, without affecting food intake. In addition, rats born from protein restricted and methyl donor supplemented dams gained less weight when fed a hypercaloric diet. Methylation of the leptin gene promoter in adipose tissue was increased in methyl donor supplemented groups but not affected by protein restriction only. These results suggest that maternal methyl donor supplementation may influence energy homeostasis in a gender-dependent manner, without affecting food intake. Moreover, we showed that macronutrients and micronutrients in maternal diet interact to influence the programming of the offspring.

Antioxidative activity and protective effect of probiotics against high-fat diet-induced sperm damage in rats.

In this study, antioxidant capability and protective effect of probiotics on reproductive damage induced by diet oxidative stress were investigated. Thirty male Sprague-Dawley rats were randomly divided into three groups with 10 rats in each group. The control group consumed a normal standard diet (5% fat, w/w). The other two treatment groups were fed with a high-fat diet (20% fat, w/w), and a high-fat diet supplemented with 2% probiotics (w/w), respectively. At the end of the experimental period, that is, after 6 weeks, rats were killed. Activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), contents of nitric oxide (NO) free radical and malondialdehyde (MDA) in serum and sperm suspension were examined. Sperm parameters including sperm concentration, viability, motility and DNA integrity were analyzed. The results showed that high-fat diet could induce oxidative stress, shown as significant increases in lipid peroxidation, NO free radical, significant decrease in activities of SOD, GSH-Px, significant reduction in sperm concentration, viability and motility, and damage in sperm DNA (P < 0.05), compared with the control group. These alterations were significantly reversed in the probiotics-supplemented group and had no significant difference in antioxidant capability, lipid peroxidation and sperm parameters compared with the control group. The percentage of sperm with DNA damage was significantly lower than the high-fat diet group and still higher than the control group, which means that probiotics could attenuate sperm damage to some extent. The present results indicated that dietary probiotics had antioxidant activity and the protective effect against sperm damage induced by high-fat diet to some extent.

Effects of cyclic heat stress or vitamin C supplementation during cyclic heat stress on HSP70, inflammatory cytokines, and the antioxidant defense system in Sprague Dawley rats.

A total of 21 male SD rats were divided into three groups to investigate the effects of consecutive cyclic heat stress or vitamin C under heat stress on heat shock protein (HSP) 70, inflammatory cytokines, and antioxidant systems. The heat stress (HS) and vitamin C supplementation during heat stress (HS+VC) groups were exposed to cyclic heat stress (23 to 38 to 23°C) for 2 h on each of seven consecutive days. The HS+VC group had free access to water containing 0.5% vitamin C throughout the experiment. Hepatic HSP70 mRNA in the HS group was significantly (P<0.05) higher than that in the control (CON) or HS+VC group. The mRNA levels of tumor necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS) in the HS group were greater (P<0.05) than those in the CON group. The HS+VC group showed significantly (P<0.05) lower mRNA levels of hepatic interleukin-6 and TNF-α than the HS group. However, thymic HSP70 and inflammatory cytokines were unaffected by treatments. In the hepatic antioxidant system, the mRNA and activity of glutathione peroxidase (GPX) were greater (P<0.05) in the HS than in the CON group, whereas the HS+VC group showed markedly (P<0.05) lower GPX mRNA and activity than the HS group. However, superoxide dismutase, glutathione S-transferase, and malondialdehyde were unaffected by treatments. In conclusion, cyclic heat stress activated hepatic HSP70, TNF-α, iNOS, and GPX genes, whereas vitamin C during heat stress ameliorated heat stress-induced cellular responses in rats.

Neuron differentiation-related genes are up-regulated in the hypothalamus of odorant-inhaling rats subjected to acute restraint stress.

To elucidate some physiopsychological effects of a pleasant odor, we analyzed gene expression profiles in the hypothalamus of rats which, under a restraint-stressed condition, inhaled (R)-(-)-linalool. Consequently, 697 probe sets showed significant expression changes in the odorant-inhaling rats subjected to 2 h of restraint stress (false discovery rate < 0.05). We observed up-regulation of 594 among them, including genes related to neuron differentiation and transcriptional regulatory factors. Another important result was that inhalation of (R)-(-)-linalool returned the expression of 49 restraint-regulated genes to a normal condition. In contrast, the inhalation also further up-regulated the expression of 16 restraint-up-regulated genes that included those encoding heat shock proteins as factors to induce some biological responses against stresses. In the present study we thus found the substantial example that, in the hypothalamus involved in feeding behaviors, an inhaled pleasant odor acts to regulate the gene expression related to the functions of neuronal developments to cope with stresses.

Fecal dehydroepiandrosterone (DHEA) immunoreactivity as a noninvasive index of circulating DHEA activity in young male laboratory rats.

Evidence suggests that dehydroepiandrosterone (DHEA) plays a key role in stress and coping responses. Fecal sampling permits assessment of hormone-behavior interactions reliably and effectively, but no previous study has compared circadian- or stress-dependent alterations between serum DHEA and its fecal metabolites. In the current study, young (28 d of age) male rats were assigned to either an experimental (n = 6) or control (n = 6) group. Rats in the experimental group were exposed to a forced swim test to assess their behavioral and physiologic response to an environmental stressor; blood samples were drawn before the test (baseline), immediately after the test, and at 2 later time points. Only fecal samples were collected from control animals. Fecal DHEA and corticosterone metabolites were monitored in all animals for 24 h. DHEA metabolites in control rats exhibited significant diurnal variation, showing a similar temporal pattern as that of corticosterone metabolites. In addition, fecal and serum DHEA levels were highly correlated. Significant peaks in both DHEA and corticosterone metabolite levels were detected. These data suggest that measures of fecal DHEA can provide a complementary, noninvasive method of assessing adrenal gland function in rats.

Invasive rats alter woody seedling composition on seabird-dominated islands in New Zealand.

Invasive rats (Rattus rattus, R. norvegicus, R. exulans) have large impacts on island habitats through both direct and indirect effects on plants. Rats affect vegetation by extirpating burrowing seabirds through consumption of eggs, chicks, and adults. These seabirds serve as ecosystem engineers, affecting plant communities by burying and trampling seeds and seedlings, and by altering microclimate. Rats also directly affect plant communities by consuming seeds and seedlings. We studied the direct and indirect impacts of rats on the seedlings of woody plants on 21 islands in northern New Zealand. We compared seedling densities and richness on islands which differed in status with respect to rats: nine islands where rats never invaded, seven islands where rats were present at the time of our study, and five islands where rats were either eradicated or where populations were likely to be small as a result of repeated eradications and re-invasions. In addition, we compared plots from a subset of the 21 islands with different burrow densities to examine the effects of burrowing seabirds on plants while controlling for other factors that differ between islands. We categorized plant communities by species composition and seedling density in a cluster analysis. We found that burrow densities explained more variation in seedling communities than rat status. In areas with high seabird burrow density seedling densities were low, especially for the smallest seedlings. Species richness and diversity of seedlings, but not seedling density, were most influenced by changes in microclimate induced by seabirds. Islands where rats had been eradicated or that had low rat populations had the lowest diversity and richness of seedlings (and adults), but the highest seedling density. Seedling communities on these islands were dominated by Pseudopanax lessonii and Coprosma macrocarpa. This indicates lasting effects of rats that may prevent islands from returning to pre-invasion states.

[Application of rat's praxiology evaluation to researches on the mechanism of acupuncture in the treatment of some diseases].

The present paper reviews recent progress about the application of rat's praxiology evaluation in studies on the mechanism of acupuncture in the treatment of some diseases from 1) motor functional impairment evaluation; 2) cognition impairment evaluation; 3) animal mood score, and 4) pain behavior evaluation. By using different praxiology evaluation methods, the acupuncture curative effect has been confirmed repeatedly in different pathological models. The animal experimental study plays an important role in understanding the mechanisms of acupuncture in the treatment of some common diseases in clinic. However, due to the multiplicity of diseases, and specificity of various phases of a disease, extensive and specific behavior evaluation methods are relatively fewer, some current method terms are still obscure and manual of operations is deficient. Therefore, further improvement of the current behavior evaluation methods and developing more methods with stronger and specific functions aiming at different experiments (disease models) are definitely necessary.

Food-intake-regulating-neuropeptides are expressed and regulated through pregnancy and following food restriction in rat placenta.

BACKGROUND: Neuropeptide Y (NPY), agouti related peptide (AgRP), cocaine and amphetamine-regulated transcript (CART) and melanocortins, the products of the proopiomelanocortin (POMC), are hypothalamic peptides involved in feeding regulation and energy homeostasis. Recent evidence has demonstrated their expression in rat and human placenta. METHODS: In the current study, we have investigated the expression of those neuropeptides in the rat placenta by real-time PCR using a model of maternal food restriction. RESULTS: Our results showed that placental-derived neuropeptides were regulated through pregnancy and following food restriction. CONCLUSION: These data could indicate that placental-derived neuropeptides represent a local regulatory circuit that may fine-tune control of energy balance during pregnancy.

A two-generational reproductive toxicity study of zinc in rats.

A two-generation reproductive toxicity study of zinc chloride (ZnCl(2)) was conducted in rats. F(o) male and female rats were administered 0.00 (control), 7.50 (low), 15.00 (mid) and 30.00 (high) mg/kg/day of ZnCl(2). Selected F(1) male and female rats were exposed to the same doses received by their parents (F(o)). Exposure of F(0) parental rats to ZnCl(2) showed significant reduction in fertility, viability (days 0 and 4), and the body weight of F(1) pups from the high-dose group but caused no effects on litter size, weaning index, and sex ratio. Similarly, the continued exposure of F(1) parental rats to ZnCl(2) also reduced fertility, liter size, viability (day 0), and the body weight of F(2) pups within the high-dose group but caused no effects on weaning index and sex ratio. Exposure of ZnCl(2) to F(0) and F(1) parental males resulted in a significant reduction in their body weights, and the F(0) and F(1) parental females did not show any significant difference in their body weights compared to their control groups. However, the postpartum dam weights of both F(0) and F(1) female rats were significantly reduced compared to their controls. Exposure of ZnCl(2) to F(o) and F(1) generation parental rats did not produce any significant change of their clinical signs as well as their clinical pathology parameters, except the alkaline phosphotase (ALK) level, which showed an upward trend in both sexes of both generations. Exposure of ZnCl(2) to F(0) rats resulted in a reduction of brain, liver, kidney, spleen and seminal vesicles weights of males and in the spleen and uterus of females. Similarly, exposure of F(1) rats to ZnCl(2) also resulted in reduction of brain, liver, kidney, adrenal, spleen, prostate and seminal vesicles weights of males and in spleen and uterus of females. ZnCl(2) exposure resulted in grossly observed gastro-intestianla (GI) tract, lymphoreticular/hematopoietic, and reproductive tract lesions in parental rats in both generations. Reduced body fat was also recorded in F(1) parental rats.

Rodenticide grain bait ingredient acceptance by Norway rats (Rattus norvegicus), California ground squirrels (Spermophilus beecheyi) and pocket gophers (Thomomys bottae).

Vertebrate pest control in California is often accomplished through the use of rodenticide grain baits. These grain baits are composed of steam-rolled oats (SRO), a toxicant, an indicator dye and an oil combination. A series of tests were performed to determine the effects of various dye and oil formulations on acceptance of grain bait by Norway rats [Rattus norvegicus (Berk)], California ground squirrels [Spermophilus beecheyi (Richardson)] and pocket gophers (Thomomys bottae Eyd & Gerv). Seven different dyes, four oil formulations and clean (untreated) oats were tested for acceptance. The addition of the selected oils and dyes to grain resulted in no significant differences in consumption. This indicates that there is a wide variety of dyes that could be used in the formulation of rodenticides. These alternatives could aid in proper pesticide use, the deterrence of bait consumption by birds and possibly in ingredient adhesion to the finished bait.

The effects of L-arginine and L-NAME supplementation on redox-regulation and thermogenesis in interscapular brown adipose tissue.

Changes in inducible nitric oxide synthase (iNOS) protein levels and its relationship with the hyperplasia and uncoupling protein 1 (UCP1) levels were examined in interscapular brown adipose tissue (IBAT) of adult rat males receiving L-arginine (L-Arg; 2.25%) or N-nitro-L-arginine methyl ester (L-NAME; 0.01%) as a drinking liquid and maintained at low (4+/-1 degrees C) or room (22+/-1 degrees C) temperature for 45 days. Cold generally diminished both iNOS immunopositivity and protein level in IBAT, as well as the rate of apoptosis. Among groups acclimated to cold, higher iNOS immunopositivity and protein levels were detected only in the L-Arg-treated group. Furthermore, chronic L-Arg treatment increased IBAT mass and UCP1 protein content, while L-NAME had an opposite effect, decreasing both IBAT mass and UCP1 protein level, as compared to the control maintained at 4+/-1 degrees C. These data suggest that nitric oxide (NO) produced by iNOS could also contribute to overall NO-associated regulation of thermogenesis in IBAT. Namely, that iNOS, i.e. NO, in correlation with enhanced thermogenesis, additionally induced IBAT hyperplasia and UCP1 level compared to that induced by low temperature. Cooperative action of decreased apoptosis accompanied by increased tissue hyperplasia and UCP1 level, observed in IBAT of cold-acclimated rats, would be a way of meeting the metabolic requirements for increased thermogenesis.