Lycopene supplementation does not change productive performance but lowers egg yolk cholesterol and gene expression of some cholesterol-related proteins in laying hens.

1. This work examined the effects of purified lycopene (LYC) supplementation or a source of LYC as tomato powder (TP) on productive performance, egg yolk cholesterol levels as well as gene expression related to mechanism and regulation of cholesterol.2. One hundred and fifty laying hens (Lohman LSL, hybrid) were randomly divided into one of three treatments, with 10 replicates of five hens per cage, totalling 50 hens per treatment. The hens were fed either a standard diet (control) or a standard diet supplemented with 20 mg purified lycopene/kg diet (LYC) or an equal amount of lycopene-containing tomato powder (TP) for 12 weeks.3. Feed consumption, egg production, and feed efficiency remained similar among treatments (P ≥ 0.27). Supplementing lycopene, either as a purified form or in TP, increased the levels of serum and egg yolk lycopene and reduced serum and egg yolk cholesterol concentrations (P < 0.001). Supplementation in either form decreased gene expression for intestinal NPC1L1, MTP, ACAT2, hepatic SREBP1c, ACLY, and LXRα but increased hepatic ABCG5 and ABCG8 (P < 0.001).4. The results of the present work revealed that egg yolk cholesterol metabolism is regulated by the modulation of a group of genes, particularly with LYC supplementation.

Muscle structure and gene expression in pectoralis major muscle in response to deep pectoral myopathy induction in fast- and slow-growing commercial broilers.

1. The objective of this study was to determine muscle structure and gene expression in pectoralis major (p. major) muscle of broilers in response to deep pectoral myopathy (DPM) induction. 2. A total of 160 chickens from slow- and fast-growing broilers were raised under same conditions. Half of the broilers from each strain were encouraged to wing flap when they reached 2800 g body weight. Pectoralis minor (p. minor) muscle of the broilers was inspected for the occurrence of DPM and p. major samples were collected from broilers with or without DPM. The muscle fibre area and number, capillary number and the signalling pathways of vascular development (vascular endothelial growth factor A, VEGFA) and muscle contraction regulation (actin alpha 1, ACTA1; myosin light chain kinase 2, MYLK2 and ATPase Ca+2 transporting gene 1, ATP2A1) were studied in p. major muscle. 3. DPM induction increased fibre area of p. major muscle with a greater rate in the slow-growing strain compared with fast-growing line. Although the capillary number was higher in slow-growing compared with fast-growing broilers, in the case of DPM induction, the number of capillaries was similar between strains. 4. Expression of VEGFA, MYLK2 and ATP2A1 was greater in slow- than in fast-growing broilers. DPM induction increased expression of ACTA1, VEGFA and ATP2A1 in p. major muscle of broilers from both strains; however, MYLK2 expression was downregulated. 5. Changes in capillary density and expression of VEGFA found in the p. major muscle of broilers with DPM suggest increased blood flow to increase oxygen availability. The upregulation of ATP2A1 by DPM induction could be attributable to alterations in calcium ion transportation from the cytoplasm into the sarcoplasmic reticulum. 6. The results are evidence of changes in muscle structure and gene expression pathways in p. major muscle of broilers with DPM.

Organic chromium modifies the expression of orexin and glucose transporters of ovarian in heat-stressed laying hens.

In this study, the effect of the supplemental organic chromium (Cr) forms on the expression of ovarian orexin(hypocretin), glucose transporters (GLUTs), heat shock proteins (HSPs) andnuclear factor-kappaB (NF-κB)were investigated in laying hens (HS). Laying hens (n=1800; 16-wk-old; Lohmann LSL-Lite) were allocated to 6 random groups according to a 2 × 3 factorial trial scheme with two different environmental temperatures [Thermoneutral (TN groups; at either 22±2 °C 24 h/d)  and heat stress (HS groups; at 34±2 °C for 8 h/d, 08:00 to 17:00 h, followed by 22°C for 16 h for a period of 12 wks)], andhens reared under both environmental conditions were fed either a basal diet or the basal diet supplemented with 1.600 mg of chromium-picolinate (CrPic, 12.43% Cr) and 0.788 mg of chromium-histidinate (CrHis, 25.22% Cr) per kg of diet, delivering 200 µg elemental Cr per kg diet. HS groups showed decreased levels of orexin and GLUTs(GLUT1, GLUT4), and increased NFκB, HSP60, HSP70 and HSP90 levels compared to the TN groups in ovarian tissue of hens (P < 0.0001 for all).However, dietary chromium supplementation (CrPic-CrHis) increasedorexin and GLUTs levels and significantly reduced the NF-κB and HSPs levels making them closer to those of thermoneutral group (P < 0.0001).In conclusion, CrPic and CrHis showed supported the relief and treatment of stress complications.

Capsaicinoids improve egg production by regulating ovary nuclear transcription factors against heat stress in quail.

1. To examine the molecular mechanism of capsaicinoid supplementation from capsicum extract, laying Japanese quail (n = 180, 5 weeks old) were reared either at 22°C for 24 h/d (thermoneutral, TN) or at 34°C for 8 h/d (heat stress, HS) and fed on one of three diets containing 0, 25 or 50 mg of capsaicinoids per kilogram for 12 weeks (2 × 3 factorial arrangement). 2. The results revealed that exposure to HS decreased feed consumption by 10.7% and egg production by 13.6%, increased serum and ovary malondialdehyde (MDA) levels by 66.9% and 88.1%, respectively, and reduced ovary superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities by 28.3%, 48.7% and 43.8%, respectively. 3. There were magnifications in the ovary nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) levels by 42.4% and suppressions in nuclear factor (erythroid-derived 2)-like 2 (Nrf2), protein kinase B (Akt) and haem-oxygenase 1 (HO-1) levels by 29.2%, 38.2% and 30.7%, respectively, in heat-stressed quail. 4. With increasing supplemental capsaicinoids, there were linear increases in egg production, antioxidant enzyme activity, linear decreases in ovary MDA and NF-κB levels and linear increases in ovary Nrf2, Akt and HO-1 levels at a greater extent in quail reared under TN condition than those reared under HS condition. Two-way treatment interactions showed that the degree of restorations in all response variables was more notable under the HS environment than under the TN environment as supplemental capsaicinoid level was increased. 5. In conclusion, capsaicinoid supplementation alleviates oxidative stress through regulating the ovary nuclear transcription factors in heat-stressed quail.

Lycopene activates antioxidant enzymes and nuclear transcription factor systems in heat-stressed broilers.

This study was conducted to evaluate the effects of dietary lycopene supplementation on growth performance, antioxidant status, and muscle nuclear transcription factor [Kelch like-ECH-associated protein 1 (Keap1) and (erythroid-derived 2)-like 2 (Nrf2)] expressions in broiler chickens exposed to heat stress (HS). A total of 180 one-day-old male broiler chicks (Ross 308) were assigned randomly to one of 2×3 factorially arranged treatments: two housing temperatures (22°C for 24 h/d; thermoneutral, TN or 34°C for 8 h/d HS) and three dietary lycopene levels (0, 200, or 400 mg/kg). Each treatment consisted of three replicates of 10 birds. Birds were reared to 42 d of age. Heat stress caused reductions in feed intake and weight gain by 12.2 and 20.7% and increased feed efficiency by 10.8% (P<0.0001 for all). Increasing dietary lycopene level improved performance in both environments. Birds reared under the HS environment had lower serum and muscle lycopene concentration (0.34 vs. 0.50 µg/mL and 2.80 vs. 2.13 µg/g), activities of superoxide dismutase (151 vs. 126 U/mL and 131 vs. 155 U/mg protein), glutathione peroxidase (184 vs. 154 U/mL and 1.39 vs. 1.74 U/mg protein), and higher malondialdehyde (MDA) concentration (0.53 vs. 0.83 µg/mL and 0.78 vs. 0.45 µg/ mg protein) than birds reared under the TN environment. Changes in levels of lycopene and MDA and activities of enzymes in serum and muscle varied by the environmental temperature as dietary lycopene level increased. Moreover, increasing dietary lycopene level suppressed muscle Keap1 expression and enhanced muscle Nrf2 expression, which had increased by 150% and decreased by 40%, respectively in response to HS. In conclusion, lycopene supplementation alleviates adverse effects of HS on performance through modulating expressions of stress-related nuclear transcription factors.

Chromium-histidinate ameliorates productivity in heat-stressed Japanese quails through reducing oxidative stress and inhibiting heat-shock protein expression.

An experiment was conducted to evaluate the effects of a histidine complex of chromium (chromium histidinate, CrHis) on egg production, lipid peroxidation and the expression of hepatic nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and heat-shock proteins (HSPs) in Japanese quails (Coturnix coturnix japonica) exposed to heat stress (HS). A total of 180 5-week-old female quails were reared either at 22°C for 24 h/d (thermoneutral, TN) or 34°C for 8 h/d (heat stress, HS) for 12 weeks. Birds in both environments were randomly given one of three diets: basal diet and basal diet supplemented with 400 or 800 µg of elemental Cr as CrHis per kg of diet. Blood, egg yolk and liver samples collected at the end of the trial were analysed to determine concentrations of cholesterol and malondialdehyde (MDA) and expressions of transcription and heat-shock proteins. Exposure to HS caused reductions in feed intake (-8.1%) and egg production (-15.8%), elevations in serum (14.8%) and egg-yolk (29.0%) cholesterol concentrations, decreases in serum (113%) and egg-yolk (73.0%) MDA concentrations and increases in the expressions of hepatic NF-κB (52.3%) and HSPs (averaging 53.6%). The effects of increasing supplemental CrHis on the response variables were more notable in the HS environment than in the TN environment. There were considerable improvements in feed intake and egg production, decreases in serum and egg-yolk cholesterol concentrations and suppressions in the expressions of hepatic nuclear protein and HSPs in response to increasing supplemental CrHis concentration in the diet of quails reared under the HS environment. In conclusion, supplemental CrHis improves productivity through alleviating oxidative stress and modulating the expressions of hepatic NF-κB and HSPs in heat-stressed quails.

Epigallocatechin-3-gallate exerts protective effects against heat stress through modulating stress-responsive transcription factors in poultry.

1. The aim of the study was to describe the effect of Epigallocatechin-3-gallate (EGCG), a polyphenol derived from green tea, on activator protein-1 (AP-1) components (phospho-c-Jun and c-Fos), cyclooxygenase-2 (COX-2) and heat shock proteins (HSPs) in the liver of heat-stressed quails. 2. A total of 180 5-week-old female Japanese quails were reared either at 22°C for 24 h/d (thermoneutral, TN) or 34°C for 8 h/d (heat stress, HS) for 12 weeks. Birds in both environments were randomly given 1 of 3 diets: basal diet and basal diet with 200 or 400 mg of EGCG added per kilogram of diet. 3. The hepatic c-Jun, c-Fos, COX-2 and HSPs gene expression for quails reared under the HS environment was greater than those reared under the TN environment. Supplemental EGCG decreased hepatic expression of these proteins at a greater extent under HS than TN. 4. In conclusion, suppression of AP-1 COX-2 and HSPs may partly account for the inhibitory effect of EGCG in heat-stressed quail.

Chromium histidinate protects against heat stress by modulating the expression of hepatic nuclear transcription factors in quail.

1. This experiment was conducted to evaluate the effects of supplemental chromium histidinate (CrHis) on performance and expressions of hepatic nuclear factors kappaB, an enhancer (NF-κB) and an inhibitor (IκBα) of activated B cells in heat-stressed Japanese quail (Coturnix coturnix japonica). 2. A total of 180, 10-d-old Japanese quail were allocated randomly into 6 groups in a 2 × 3 factorial arrangement. Birds were reared either at 22°C for 24 h/d (thermoneutral, TN) or 34°C for 8 h/d (heat stress, HS) for 32 d and fed on one of three diets supplemented with 0, 400 or 800 µg of CrHis per kg of diet. Each group consisted of 10 cages, each containing three quail. Data (performance variables and hepatic NF-κB and IκBα) were analysed using 2-way ANOVA. 3. Heat stress caused reductions in cumulative feed intake (FI) by 5·7%, weight gain (WG) by 13·0%, final body weight (FBW) by 10·3%, carcase weight by 12·6% and carcase efficiency by 2·3% and an increase in feed conversion ratio (FCR, feed consumed, g:weight gained, g) by 8·4%. As supplemental CrHis level increased up to 800 µg/kg, there were linear increases in cumulative FI (from 602 to 609 g), WG (from 134 to 138 g), FBW (from 167 to 171 g), cold carcase weight (from 110 to 114 g) and cold carcase efficiency (from 65·5 to 66·4%) and a decrease in FE (from 4·51 to 4·42). The environmental temperature by CrHis level interaction effect on performance parameters was insignificant. Hepatic NF-κB p65 concentration was higher and hepatic IκBα concentration was lower in quail exposed to HS than in quail kept at TN temperature. Increasing supplemental CrHis level linearly inhibited hepatic NF-κB p65 expression from 134·4 to 105·3% and linearly enhanced hepatic IκBα expression from 73·4 to 99·6%. The decrease in hepatic NF-κB expression and the increase in hepatic IκB expression were more notable in the TN environment than in the HS environment. 4. In conclusion, heat stress depressed performance variables and augmented lipid peroxidation and supplemental CrHis alleviated oxidative stress through modulating expressions of stress-related hepatic nuclear transcription factors (NF-κB and IκBα).

Resveratrol protects quail hepatocytes against heat stress: modulation of the Nrf2 transcription factor and heat shock proteins.

In the present study, the effects of dietary resveratrol on the induction of heat shock proteins, transcription factors and antioxidative enzyme system in liver of quails under heat stress were investigated. A total of 180 (55-day-old) female Japanese quails (Coturnix coturnix japonica) were reared either at 22 °C for 24 h/day (thermoneutral, TN) or 34 °C for 8 h/day (heat stress, HS; 09:00-17:00 hours) for 12 weeks. Birds in both environments were randomly fed one of three diets: basal diet and basal diet added with either 200 or 400 mg of resveratrol per kg of diet. The results showed that exposure to high ambient temperature induced decreases in feed intake, egg production, and hepatic superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities but increases in hepatic malondialdehyde (MDA) concentrations (p < 0.001). Liver Hsp70, Hsp90 and NF-κB expression was greater while Nrf2 expression was lower for quails reared under the heat stress than for those reared under the TN environment (p < 0.0001). There were linear increases in feed intake, egg production, hepatic SOD, CAT, and GSH-Px activities as well as Nrf2 expression, but linear decreases in hepatic MDA concentrations and Hsp70, Hsp90, and NF-κB expressions with increasing supplemental resveratrol level (p < 0.0001). Two-way treatment interactions revealed that the degree of restorations in all response variables was more notable under the high ambient temperature than that of the TN environment as dietary resveratrol concentration was increased. The results of the present study suggest that supplemental resveratrol reduces oxidative stress in heat-stressed quails through modulating the hepatic heat shock proteins and nuclear transcription factors.

Effects of dietary resveratrol supplementation on egg production and antioxidant status.

Resveratrol, a polyphenol derived from red grapes, berries, and peanuts, exerts antiinflammatory, antioxidant, and immunomodulatory effects. The objective of this study was to investigate the effects of dietary resveratrol supplementation on performance and serum and egg yolk antioxidant status in quail (Coturnix coturnix japonica). A total of 150 five-week-old quails were allocated randomly to 1 of 3 dietary treatments: basal diet and basal diet supplemented with 200 or 400 mg of resveratrol/kg of diet. Each diet was offered to 10 cages of 5 birds in each from 4 to 16 wk of age. Serum and egg samples were collected at the beginning and end the experimental period to be evaluated for malondialdehyde (MDA), vitamin A, and vitamin E. Data were subjected to analysis of covariance using the MIXED procedure. There was no treatment effect on feed intake, egg production, or egg quality parameters related to shell, yolk, and albumen. There were no effects of resveratrol supplementation on serum and egg yolk vitamin A concentrations. The quails supplemented with resveratrol had a lower serum MDA concentration (0.56 vs. 0.88 mg/L, P<0.03) and a higher serum vitamin E concentration (5.72 vs. 3.56 mg/L, P<0.008) than those not supplemented with resveratrol. Moreover, there was a linear decrease in serum MDA concentration (P<0.02) and a linear increase in serum vitamin E concentration (P<0.01) as supplemental resveratrol level increased. The treatment groups had less egg yolk MDA concentration than the control group (0.21 vs. 0.15 microg/g, P<0.002). Egg yolk MDA concentration decreased linearly in response to increasing dietary resveratrol level (P<0.0003). In conclusion, inclusion of resveratrol up to 400 mg/kg into quail diets enhanced antioxidant status of birds and eggs. Further studies should investigate the carryover effects of dietary resveratrol supplementation on product quality with respect to shelf life, antioxidant stability, and its nutritive value for human consumption.

Epigallocatechin-3-gallate prevents lipid peroxidation and enhances antioxidant defense system via modulating hepatic nuclear transcription factors in heat-stressed quails.

Epigallocatechin-3-gallate (EGCG), a polyphenol derived from green tea, exerts antioxidant effects. Oxidative stress is one of the consequences of heat stress (HS), which also depresses performance in poultry. This experiment was conducted to elucidate the action mode of EGCG in alleviation of oxidative stress in heat-stressed quail (Coturnix coturnix japonica). A total of 180 five-week-old female Japanese quails were reared either at 22°C for 24 h/d (thermoneutral, TN) or 34°C for 8 h/d (HS) for 12 wk. Birds in both environments were randomly fed 1 of 3 diets: basal diet and basal diet added with 200 or 400 mg of EGCG/kg of diet. Each of the 2×3 factorially arranged groups was replicated in 10 cages, each containing 3 quails. Performance variables [feed intake (FI) and egg production (EP)], oxidative stress biomarkers [malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px)] and hepatic transcription factors [nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2)] were analyzed using 2-way ANOVA. Exposure to HS caused reductions in FI by 9.7% and EP by 14.4%, increased hepatic MDA level by 84.8%, and decreased hepatic SOD, CAT, and GSH-Px activities by 25.8, 52.3, and 45.5%, respectively (P<0.0001 for all). The hepatic NF-κB expression was greater (156 vs. 82%) and Nrf2 expression was lower (84 vs. 118%) for quails reared under the HS environment than for those reared under the TN environment (P<0.0001 for both). In response to increasing supplemental EGCG level, there were linear increases in FI from 29.6 to 30.9 g/d and EP from 84.3 to 90.1%/d, linear decreases in hepatic MDA level from 2.82 to 1.72 nmol/g and Nrf2 expression from 77.5 to 123.3%, and linear increases in hepatic SOD (146.4 to 182.2), CAT (36.2 to 47.1), and GSH-Px (13.5 to 18.5) activities (U/mg of protein) and NF-κB expression (149.7 to 87.3%) (P<0.0001 for all). Two-way treatment interactions revealed that the degree of restorations in all response variables was more notable under the HS environment than under the TN environment as supplemental EGCG level was increased. Moreover, levels of oxidative biomarkers were strongly correlated with expressions of hepatic nuclear transcription factors. In conclusion, supplemental EGCG alleviates oxidative stress through modulating the hepatic nuclear transcription factors in heat-stressed quails.

Pathological, biochemical and haematological investigations on the protective effect of alpha-lipoic acid in experimental aflatoxin toxicosis in chicks.

1. The purpose of this study was to investigate the protective effect of alpha-lipoic acid (LA) on aflatoxin (AF) toxicosis in chicks. 2. Groups of 10 Ross PM3 chicks were given, for 21 d, no AF (C), 60 mg/kg/bwt of alpha-lipoic acid (LA), 150 ppb of aflatoxin (AF1), 150 ppb of aflatoxin plus 60 mg/kg/bwt of alpha-lipoic acid (AF1 + LA), 300 ppb of aflatoxin (AF2), and 300 ppb of aflatoxin plus 60 mg/kg/bwt of alpha-lipoic acid (AF2 + LA). Before the animals were killed, blood samples were drawn for haematological analysis, and then tissue samples were collected for histopathological investigation. Immunohistochemical staining was performed against inducible nitric oxide synthase (iNOS) and nitrotyrosine on liver samples. Apoptotic cell death in liver was assessed by in situ TUNEL assay. The malondialdehyde (MDA) and reduced glutathione (GSH) concentrations in liver and kidney were also determined. 3. Hydropic degeneration and occasional necrosis, bile duct hyperplasia and periportal fibrosis were observed in the livers of AF-treated groups. The severity of these changes was reduced in LA-supplemented AF groups. Occasionally, thymic cortical atrophy, lymphoid depletion in spleen and bursa of Fabricius, and degeneration in the kidney tubule epitheliums were detected in AF groups. The severity of these degenerative changes was slightly reduced in LA supplemented groups. 4. There was moderate to strong iNOS and nitrotyrosine immunoreactivity in the livers of AF groups, while decreased immunoreactivity was observed against both antibodies in the LA supplemented groups. Apoptotic cells were numerous in the AF groups, while greatly reduced in LA supplemented groups. 5. In the liver and kidney of AF-treated groups given 300 ppb of aflatoxin, MDA concentrations were increased as GSH decreased, compared to the control group. LA supplementation of AF-treated birds improved the results compared to the AF only groups, however a statistical difference was observed only in liver tissues between AF2 + LA and AF2 groups. Haematological variables showed no differences among the groups. 6. In conclusion, supplementation of feed with the antioxidant LA, might ameliorate the degenerative effects caused by aflatoxin due to lipid peroxidation.

The effects of vitamin C and E supplementation on heat shock protein 70 response of ovary and brain in heat-stressed quail.

1. The effects of vitamin C (L-ascorbic acid) and vitamin E (alpha-tocopherol acetate) supplementation on egg production and heat shock protein 70 (Hsp70) response of ovary and brain in the Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature were evaluated. 2. The birds (n = 540; 55 d old) were randomly assigned to 18 groups consisting of 3 replicates of 10 birds each in a 2 x 3 x 3 factorial arrangement of treatments. Birds were kept in wire cages in a temperature-controlled room at either 22 degrees C (thermo-neutral, TN) or 34 degrees C (heat stress, HS) for 8 h/d (09:00 to 17:00 h; until the end of the study) and fed on a basal diet or the basal diet supplemented with either three levels of vitamin C (0, 250 and 500 mg of L-ascorbic acid/kg of diet) or three levels of vitamin E (0, 250 and 500 mg of dl-alpha-tocopheryl acetate/kg of diet). 3. Feed intake and egg production were not affected by vitamin C and E supplementation under thermo-neutral conditions. However, feed intake and egg production were increased with the vitamin C or E supplementation either singly or in combination in heat-stressed quail. When vitamin was added, feed intake and egg production of quails under TN were different from those raised under HS. However, in the absence of supplemental vitamins, feed intake and egg production at TN and HS were no different. 4. Heat exposure increased serum corticosterone levels and Hsp70 expression. Serum corticosterone level was significantly decreased by vitamin C or E supplementation in HS groups for quail. Ovary and brain Hsp70 expression linearly decreased as dietary vitamin C or vitamin E supplementation increased in heat-stressed groups. However, Hsp70 expression of ovary and brain was not affected by vitamin C or E supplementation under thermo-neutral conditions. 5. The present study showed that a combination of dietary vitamin C (500 mg) and E supplementation (500 mg) may alleviate some heat stress effects of heat shock proteins of ovary and brain and egg production of Japanese quail.

Effects of letrozole on hippocampal and cortical catecholaminergic neurotransmitter levels, neural cell adhesion molecule expression and spatial learning and memory in female rats.

We have investigated effects of letrozole, an aromatase inhibitor, on spatial learning and memory, expression of neural cell adhesion molecules (NCAM) and catecholaminergic neurotransmitters in the hippocampus and cortex of female rats. In the intact model, adult Sprague-Dawley rats were divided into four groups (n=8). Control received saline alone. Letrozole was administered to the animals in the second and third groups by daily oral gavage at 0.2 and 1 mg/kg doses, respectively, for 6 weeks. Another group of letrozole-treated rats was allowed to recover for 2 weeks. In the second model, 24 rats were ovariectomized (ovx) and the first group served as control. The second group received letrozole (1 mg/kg) for 6 weeks. Ovx rats in the third group were given letrozole (1 microg/kg) plus estradiol (E(2)) (10 microg/rat). At the end, all rats were tested in a spatial version of the Morris water maze. Then they were decapitated and the brains rapidly removed. Catecholamine concentrations were determined by high performance liquid chromatography with electrochemical detection. NCAM 180, 140 and 120 isoforms were detected by Western blotting. Uterine weights were significantly reduced by letrozole in a dose-dependent manner (P<0.01) which returned to control values following 2 weeks of recovery (P<0.05). Serum E(2) levels followed a similar course (P<0.01). Although improvement in spatial learning performance of letrozole-treated rats was not statistically significant, the high-dose letrozole-treated group remained significantly longer in the target quadrant compared with the control (P<0.05). Administration of letrozole to ovx animals significantly reduced the latency (P<0.001) and increased the probe trial performance compared with ovx controls (P<0.05). Letrozole increased expression of NCAM 180 and NCAM 140 in both hippocampus and cortex of intact rats. In the cortex samples of ovx animals, NCAM 180 was overall lower than the intact control values (P<0.05). Noradrenaline, dopamine and their metabolites were decreased in the hippocampus of the letrozole-treated group (P<0.01). Letrozole had differential effects on noradrenaline and dopamine content in the cortex. It appears that inhibition of estrogen synthesis in the brain may have beneficial effects on spatial memory. We suggest that structural changes such as NCAM expression and catecholaminergic neurotransmitters in the hippocampus and prefrontal cortex may be the neural basis for estrogen-dependent alterations in cognitive functions.

The effects of tomato powder supplementation on performance and lipid peroxidation in quail.

Recent studies have suggested a protective role for lycopene, an antioxidant carotenoid, in the prevention of stress including environmental stress. Tomatoes and tomato products are the major dietary source of lycopene. The objective of the present study was to investigate the effect of dietary tomato powder supplementation on the performance and lipid peroxidation of meat in Japanese quail (Coturnix coturnix japonica) exposed to a high ambient temperature of 34 degrees C. A total of 180 ten-day-old male quails were randomly allocated into 6 groups consisting of 10 replicates of 3 birds. Birds were kept in wire cages in a temperature-controlled room at either 22 degrees C (thermoneutral) or 34 degrees C (heat stress) for 8 h/ d (0900 to 1700 h during the study). Birds were fed either a basal diet or the basal diet supplemented with 2.5 or 5.0% of tomato powder. Tomato powder supplementation linearly increased feed intake, live weight gain, and feed conversion (P = 0.01) under heat stress conditions but did not show the same effect at thermoneutral conditions (P > 0.05). Heat stress significantly increased malondialdehyde concentration and decreased vitamin concentrations in the serum, liver, and muscles of quail. Serum lycopene and vitamin C, E, and A (P = 0.01) concentrations increased linearly in birds at all groups. Malondialdehyde levels in serum, liver (P = 0.001), and muscles linearly decreased in all birds of both thermoneutral and heat stress groups as dietary tomato powder supplementation increased. The results of the study indicate that tomato powder modulates the oxidation-antioxidation system of the muscles in Japanese quail exposed to high ambient temperature.

Epigallocatechin-3-gallate supplementation can improve antioxidant status in stressed quail.

1. Heat stress causes oxidative stress, which decreases plasma antioxidants in poultry. Epigallocatechin gallate (EGCG), the most abundant polyphenol in green tea, is a powerful antioxidant against lipid peroxidation. This experiment was conducted to evaluate the effects of dietary EGCG supplementation on performance, carcase characteristics, concentrations of malondialdehyde, lipid peroxidation indicator, vitamins C, E, A, cholesterol, triglyceride, and glucose in Japanese quail (Coturnix coturnix japonica) exposed to a high ambient temperature of 34 degrees C. 2. One hundred and eighty Japanese quails (10 d old) were assigned at random to 6 treatment groups consisting of 10 replicates of three birds. Birds were kept in cages in a temperature-controlled room at either 22 degrees C (thermo-neutral) or 34 degrees C (heat stress) for 8 h/d. Birds were fed either a basal diet or the diet supplemented with 200 or 400 mg of EGCG/kg of diet. 3. EGCG supplementation linearly increased feed intake, live weight gain, feed efficiency, cold carcase weight and yield under heat stress conditions but did not show the same effect at thermoneutral conditions. Serum vitamin C, E, and A concentrations increased in birds reared at high temperature while non-significant changes occurred in thermo-neutral groups. Malondialdehyde concentrations in serum and liver decreased in all birds of both thermo-neutral and heat stressed groups as dietary EGCG supplementation increased. Heat stress-induced increase in serum cholesterol, triglycerides and glucose concentrations were linearly reversed by EGCG supplementation. 4. The results indicate that EGCG supplementation improved the live performance and antioxidant status of heat-stressed Japanese quail.

Effects of the supplemental chromium form on performance and metabolic profile in laying hens exposed to heat stress.

This experiment was conducted to compare the effect of the supplemental chromium (Cr) form on performance, egg quality, and metabolic profile in laying hens exposed to heat stress (HS). Laying hens (n = 1800; 16-wk-old; Lohmann LSL-Lite) were kept in cages in temperature-controlled rooms at either 22 ± 2°C for 24 h/d (thermoneutral, TN) or 34 ± 2°C for 8 h/d, from 08:00 to 17:00 h, followed by 22°C for 16 h (HS) for 12 wks. Hens reared under both environmental conditions were fed 1 of 3 diets: a basal diet and the basal diet supplemented with either 1.600 mg of chromium-picolinate (CrPic, 12.43% Cr) or 0.788 mg of chromium-histidinate (CrHis, 25.22% Cr) per kg of diet, delivering 200 µg elemental Cr per kg diet. Data were analyzed by 2-way ANOVA. Exposure to HS caused decreases in feed intake (P < 0.0001), egg production (P < 0.0001), egg weight (P < 0.0001), eggshell weight (P < 0.0009), eggshell thickness (P < 0.0001), eggshell strength (P < 0.0001), and Haugh unit (P < 0.0001), deterioration in feed conversion ratio (P < 0.0001), increases in serum glucose and cholesterol concentrations (P < 0.0001 for both), decreases in serum and egg yolk Cr concentrations (P < 0.0001 for both), and decreases in serum Na (P < 0.002) and K (P < 0.01) concentrations. Both Cr sources were equally effective in alleviating performance variables under the HS condition. However, neither Cr sources alleviated deteriorations in egg quality parameters and serum electrolytes. Both Cr sources decreased serum glucose and cholesterol concentrations and increased serum and egg yolk Cr concentrations under the HS condition. In conclusion, HS adversely affected laying performance, egg quality, and metabolic profile. Both CrPic and CrHis partially alleviated the adverse effect of HS on these parameters. Inclusion of either Cr source could be a part of nutritional management strategies to overcome the adverse effects of HS performance and metabolic profile in laying hens.

Effects of the supplemental chromium form on performance and oxidative stress in broilers exposed to heat stress.

This experiment was conducted to investigate effects of the organic complex form of supplemental chromium (Cr) on performance, oxidative stress markers, and serum profile in broilers exposed to heat stress (HS). A total of 1,200 10-day-old boilers (Ross-308) was divided into one of the 6 treatments (2 environmental temperatures x 3 diets with different Cr forms). The birds were kept in temperature-controlled rooms at either 22 ± 2°C 24 h/d (thermoneutral, TN group) or 34 ± 2°C for 8 h/d, 08:00 to 17:00 h, followed by 22°C for 16 h (HS group) and fed either a basal diet (C) or the basal diet supplemented with Cr (200 µg/kg) through 1.600 mg of CrPic (12.43% Cr) and 0.788 mg of CrHis (25.22% Cr). Feed intake and body weight were recorded weekly. After cervical dislocation, liver samples were harvested to analyze Cr concentration and glucose transporter-2,4 (GLUT-2,4) expression. The breast meat also was sampled for the concentration of Cr and expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa B (NF-κB). Data were analyzed by 2-way ANOVA. Heat stress caused depressions in feed intake (12.1%) and weight gain (21.1%) as well as elevations in feed conversion (11.2%) and abdominal fat (32.8%). It was also associated with depletion of Cr reserves and increases in serum concentrations of glucose, cholesterol, creatine, and enzymes. Exposure to HS was accompanied by suppression of the expressions of Nrf2 and GLUT-2 in muscle and GLUT-4 in the liver and amplification of the expression of NF-κB in muscle. Both Cr sources partially alleviated detrimental effects of HS on performance and metabolic profile. The efficacy of Cr as CrHis was more notable than Cr as CrPic, which could be attributed to higher bioavailability. In conclusion, CrHis can be added into the diet of broilers during hot seasons to overcome deteriorations in performance and wellbeing related to oxidative stress.

The importance of proteinuria as a determinant of mortality following percutaneous coronary revascularization in diabetics.

OBJECTIVES: The aims of this study were to compare mortality and clinical events following percutaneous coronary intervention (PCI) between nondiabetics and diabetics with and without proteinuria. BACKGROUND: Diabetics have increased rates of late myocardial infarction, repeat revascularization and mortality when compared with nondiabetics following PCI. Proteinuria is a marker for diabetic nephropathy and potentially a surrogate marker for advanced atherosclerosis. It is unknown if proteinuria is a predictor of outcome in diabetics following PCI. METHODS: We performed an observational study of 2,784 patients who underwent PCI at the Cleveland Clinic between January 1993 and December 1995. There were 2,247 nondiabetics and 537 diabetics with urinalysis and follow-up data available (proteinuria n = 217, nonproteinuria n = 320). The diabetic proteinuria group was further prospectively stratified into low concentration (n = 182) and high concentration (n = 35). The end points were all-cause mortality and the composite end point of death, nonfatal myocardial infarction (MI) and need for revascularization. RESULTS: The mean follow-up time was 20.2 months. The two-year mortality rate was 7.3% and 13.5% for nondiabetics and diabetics, respectively (p < 0.001). The two-year mortality rate was 9.1% and 20.3% for the nonproteinuria and proteinuria groups, respectively (p < 0.001). There was a graded increase in mortality comparing the diabetic group. The two-year mortality rate was 9.1%, 16.2% and 43.1% for the nonproteinuria, low concentration and high concentration groups, respectively (p < 0.001). The difference in survival between the nondiabetic and nonproteinuric diabetics was not significant (p = 0.8). CONCLUSIONS: The presence of proteinuria is the key determinant of risk following PCI for diabetics. Diabetics without evidence of proteinuria have similar survival compared with nondiabetics.

Melatonin inhibits neural apoptosis induced by homocysteine in hippocampus of rats via inhibition of cytochrome c translocation and caspase-3 activation and by regulating pro- and anti-apoptotic protein levels.

In the present study, we examined the molecular mechanism by which homocysteine causes neuronal cell apoptosis. We further investigated the mechanisms of melatonin's ability to reduce homocysteine-induced apoptosis. Consistent with its antioxidant properties, melatonin reduced homocysteine-induced lipid peroxidation and stimulated glutathione peroxidase enzyme activity in hippocampus of rats with hyperhomocysteinemia. Furthermore, melatonin treatment diminished cytochrome c release from mitochondria and reduced caspase 3 and caspase 9 activation induced by hyperhomocysteinemia. Chronic hyperhomocysteinemia also led to poly(ADP-ribose) polymerase cleavage and subsequently DNA fragmentation. Treatment with melatonin markedly inhibited poly(ADP-ribose) polymerase cleavage and reduced DNA damage. Hyperhomocysteinemia caused an elevation of pro-apoptotic Bax levels while reducing anti-apoptotic protein, Bcl-2, levels. Daily administration of melatonin up-regulated Bcl-2 and down-regulated Bax levels. We propose that, in addition to its antioxidant properties, melatonin has the ability to protect neuronal cells against apoptosis mediated homocysteine neurotoxicity by modulating apoptosis-regulatory proteins in the hippocampus of rats.