Dietetics, Nutrition and Biological Sciences
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Item Salience of emotional displays of danger and contagion in faces is enhanced when progesterone levels are raised(Elsevier, 2007-02) Conway, C. A.; Jones, B.; Debruine, L.; Welling, L.; Lawsmith, M.; Perrett, D. I.; Sharp, M. A.; Al-Dujaili, Emad A. S.Findings from previous studies of hormone-mediated behavior in women suggest that raised progesterone level increases the probability of behaviors that will reduce the likelihood of disruption to fetal development during pregnancy (e.g. increased avoidance of sources of contagion). Here, we tested women's (N = 52) sensitivity to potential cues to nearby sources of contagion (disgusted facial expressions with averted gaze) and nearby physical threat (fearful facial expressions with averted gaze) at two points in the menstrual cycle differing in progesterone level. Women demonstrated a greater tendency to perceive fearful and disgusted expressions with averted gaze as more intense than those with direct gaze when their progesterone level was relatively high. By contrast, change in progesterone level was not associated with any change in perceptions of happy expressions with direct and averted gaze, indicating that our findings for disgusted and fearful expressions were not due to a general response bias. Collectively, our findings suggest women are more sensitive to facial cues signalling nearby contagion and physical threat when raised progesterone level prepares the body for pregnancy.Item Development of a highly sensitive ELISA for aldosterone in mouse urine: Validation in physiological and pathophysiological states of aldosterone excess and depletion(2009-04) Al-Dujaili, Emad A. S.; Mullins, L. J.; Bailey, M. A.; Kenyon, C. J.Background: Clinical studies have established aldosterone as a critical physiological and pathophysiological factor in salt and water homeostasis, blood pressure control and in heart failure. Genetic and physiological studies of mice are used to model these processes. A sensitive and specific assay for aldosterone is therefore needed to monitor adrenocortical activity in murine studies of renal function and cardiovascular diseases. Methods: Antibodies against aldosterone were raised in sheep as previously described. HRP-Donkey-anti-sheep IgG enzyme tracer was produced in our laboratory using the Lightning-Link HRP technique. Aldosterone ELISA protocol was validated and optimised to achieve the best sensitivity. The assay was validated by analysing the urine of mice collected under various experimental conditions designed to stimulate or suppress aldosterone in the presence of other potentially interfering steroid hormones. Results: Cross-reactivity with the steroids most likely to interfere was minimal: corticosterone = 0.0028%, cortisol = 0.0006%, DOC = 0.0048% except for 5-dihydro-aldosterone = 1.65%. Minimum detection limit of this ELISA was 5.2 pmole/L (1.5 pg/mL). The validity of urinary aldosterone ELISA was confirmed by the excellent correlation between results obtained before and after solvent extraction and HPLC separation step (Y = 1.092X + 0.03, R2 = 0.995, n = 54). Accuracy studies, parallelism and imprecision data were determined and all found to be satisfactory. Using this assay, mean urinary aldosterone levels were (i) approximately 60-fold higher in females than males mice; (ii) increased 6-fold by dietary sodium restriction; (iii) increased 10-fold by ACTH infusion and (iv) reduced by >60% in Cyp11b1 null mice. Conclusion: We describe an ELISA for urinary aldosterone that is suitable for repeated non-invasive measurements in mice. Female aldosterone levels are higher than males. Unlike humans, most aldosterone in mouse urine is not conjugated. Increased levels were noted in response to dietary sodium restriction and ACTH treatment. The sensitivity of the assay is sufficient to detect suppressed levels in mouse models of congenital adrenal hyperplasia. 2009 Elsevier Inc. All rights reserved.Item Glucocorticoid receptor haploinsufficiency causes hypertension and attenuates hypothalamic-pituitary-adrenal axis and blood pressure adaptions to high-fat diet(2008-11) Michailidou, Z.; Carter, R. N.; Marshall, E.; Sutherland, H. G.; Brownstein, D. G.; Owen, E.; Cockett, K.; Kelly, V.; Ramage, L.; Al-Dujaili, Emad A. S.; Ross, M.; Maraki, I.; Newton, K.; Holmes, M. C.; Seckl, J.; Morton, N. M.; Kenyon, C. J.; Chapman, K. E.Glucocorticoid hormones are critical to respond and adapt to stress. Genetic variations in the glucocorticoid receptor (GR) gene alter hypothalamic-pituitary-adrenal (HPA) axis activity and associate with hypertension and susceptibility to metabolic disease. Here we test the hypothesis that reduced GR density alters blood pressure and glucose and lipid homeostasis and limits adaption to obesogenic diet. Heterozygous GR _geo/+ mice were generated from embryonic stem (ES) cells with a gene trap integration of a _-galactosidase-neomycin phosphotransferase (_geo) cassette into the GR gene creating a transcriptionally inactive GR fusion protein. Although GR_geo/+ mice have 50% less functional GR, they have normal lipid and glucose homeostasis due to compensatory HPA axis activation but are hypertensive due to activation of the renin-angiotensin- aldosterone system (RAAS). When challenged with a high-fat diet, weight gain, adiposity, and glucose intolerance were similarly increased in control and GR_geo/+ mice, suggesting preserved control of intermediary metabolism and energy balance. However, whereas a high-fat diet caused HPA activation and increased blood pressure in control mice, these adaptions were attenuated or abolished in GR_geo/+ mice. Thus, reduced GR density balanced by HPA activation leaves glucocorticoid functions unaffected but mineralocorticoid functions increased, causing hypertension. Importantly, reduced GR limits HPA and blood pressure adaptions to obesogenic diet. FASEB.Item Men report stronger attraction to femininity in women's faces when their testosterone levels are high(2008-11) Welling, L.; Jones, B.; Debruine, L.; Smith, F.; Feinberg, D.; Little, A.; Al-Dujaili, Emad A. S.Many studies have shown that women's judgments of men's attractiveness are affected by changes in levels of sex hormones. However, no studies have tested for associations between changes in levels of sex hormones and men's judgments of women's attractiveness. To investigate this issue, we compared men's attractiveness judgments of feminized and masculinized women's and men's faces in test sessions where salivary testosterone was high and test sessions where salivary testosterone was relatively low. Men reported stronger attraction to femininity in women's faces in test sessions where salivary testosterone was high than in test sessions where salivary testosterone was low. This effect was found to be specific to judgments of opposite-sex faces. The strength of men's reported attraction to femininity in men's faces did not differ between high and low testosterone test sessions, suggesting that the effect of testosterone that we observed for judgments of women's faces was not due to a general response bias. Collectively, these findings suggest that changes in testosterone levels contribute to the strength of men's reported attraction to femininity in women's faces and complement previous findings showing that testosterone modulates men's interest in sexual stimuli. 2008.Item Physiological and pathophysiological applications of sensitive ELISA methods for urinary deoxycorticosterone and corticosterone in rodents(Elsevier, 2009-11-04) Al-Dujaili, Emad A. S.; Mullins, L. J.; Bailey, M.; Andrew, R.; Kenyon, C. J.Deoxycorticosterone (DOC: a weak mineralocorticoid) is the precursor to corticosterone (B: the major glucocorticoid in rodents) and aldosterone (the major mineralocorticoid). The genes Cyp11b1 and Cyp11b2 that encode the enzymes responsible for DOC to B (11_-hydroxylase) and DOC to aldosterone (aldosterone synthase) conversions are located on the same chromosome. The aim of this study was to develop sensitive and specific ELISA methods to quantify urinary DOC and B concentrations to assess the physiological and genetic control of the Cyp11b1/b2 locus. Antibodies raised in rabbits against DOC and B and horse radish peroxidase-goat anti-rabbit IgG enzyme tracer were used to develop the assays. Urine samples collected from mice held in metabolic cages were extracted with dichloromethane and reconstituted in assay buffer. The assays were validated for specificity, sensitivity, parallelism, accuracy and imprecision. Cross-reactivities with major interfering steroids were minimal: DOC assay (progesterone =0.735% and corticosterone =0.045%), and for B assay (aldosterone = 0.14%,11-dehydro-B = 0.006%, cortisol =0.016% and DOC = 0.04%) and minimum detection limit for DOC ELISA was 2.2 pg/mL (6.6 pmol/L), and for B ELISA was 6.2 pg/mL (17.9 pmol/L). The validity of urinary DOC and B ELISAs were confirmed by the excellent correlation between the results obtained before and after solvent extraction and HPLC (DOC ELISA: Y = 1.092X - 0.012, R2 = 0.988; B ELISA: Y= 1.047X - 0.226, R2=0.996). Accuracy studies, parallelism and imprecision data were determined and all found to be satisfactory. The methods were used in a series of metabolic cage studies which demonstrated that: (i) females produce more DOC and corticosterone than males; (ii) DOC and corticosterone respond to ACTH treatment but not dietary sodium restriction; (iii) DOC:B ratios in Cyp11b1 null mice were >200 fold greater than wild type.Item Effects of advice on dietary intake and/or physical activity on body composition, blood lipids and insulin resistance following a low-fat, sucrose-containing, high-carbohydrate, energy-restricted diet(Informa Healthcare, 2007-08) Kirkwood, Lesley; Al-Dujaili, Emad A. S.; Drummond, SandraAim To determine the effect of dietary advice in conjunction with advice to increase physical activity on the body composition, blood lipid and insulin profiles in overweight women. Design A 12-week randomized controlled intervention study. Subjects were assigned to one of four groups: (1) no advice, (2) low-fat, high-carbohydrate (including sucrose) energy-reduced diet, (3) 60 min/day brisk walking, and (4) diet and activity advice as previous. Subjects Sixty-nine overweight women (mean age 41 years). Measurements Dietary compliance was assessed by 4-day diet diaries. Activity levels were assessed by Caltrac™ accelerator monitors. Anthropometric changes were recorded at baseline, 6 and 12 weeks. Fasting blood samples measuring glucose, insulin, and blood lipids were recorded at baseline and 12 weeks. Results Group 4 achieved greatest weight loss of 4.2 kg and greatest reduction in waist circumference of 6.5 cm. Groups 2 and 4 decreased the percentage energy from fat by 5.2%. Group 3 increased the percentage energy from fat by 4.0%. Group 4 significantly reduced total cholesterol by 0.45 mmol/l and low-density lipoprotein-cholesterol by 0.53 mmol/l. Conclusion A low-fat, high-carbohydrate, sucrose-containing diet combined with increased physical exercise resulted in greater health benefits than diet or physical activity advice alone.Item The effect of polyphenol-rich dark chocolate on fasting capillary whole blood glucose, total cholesterol, blood pressure and glucocorticoids in healthy overweight and obese subjects(Cambridge University Press, 2009-10-13) Almoosawi, Suzana; Fyfe, Lorna; Ho, Clement; Al-Dujaili, Emad A. S.Numerous studies indicate that polyphenol-rich chocolate reduces fasting blood glucose, blood pressure (BP) and total cholesterol in healthy individuals and hypertensives with or without glucose intolerance. The aim of the present study was to investigate the effect of two doses of polyphenol-rich dark chocolate (DC) on fasting capillary whole blood glucose, total cholesterol and BP and to examine whether improvements in these parameters are associated with changes in adrenocorticoid excretion in overweight and obese individuals. The study used a randomised, single-blind, cross-over design where fourteen overweight and obese subjects were randomised to either take 20 g DC with 500 mg polyphenols then 20 g DC with 1000 mg polyphenols or vice-versa. Participants followed each diet for 2 weeks separated by a 1-week washout period. It was observed that the 500 mg polyphenol dose was equally effective in reducing fasting blood glucose levels, systolic BP (SBP) and diastolic BP (DBP) as the 1000 mg polyphenol dose suggesting that a saturation effect might occur with increasing dose of polyphenols. There was also a trend towards a reduction in urinary free cortisone levels with both groups although it did not reach statistical significance. No changes in anthropometrical measurements were seen. We suggest that more research is required to investigate the mechanism(s) by which polyphenol-rich foods influence health.Item Transcriptional and physiological responses to chronic ACTH treatment by the mouse kidney(2009-11-17) Dunbar, D. R.; Khaled, H.; Evans, L. C.; Al-Dujaili, Emad A. S.; Mullins, L. J.; Mullins, J. J.; Kenyon, C. J.; Bailey, M. A.We investigated the effects on urinary steroid and electrolyte excretion and renal gene expression of chronic infusions of ACTH in the mouse. ACTH caused a sustained increase in corticosteroid excretion; aldosterone excretion was only transiently elevated. There was an increase in the excretion of deoxycorticosterone, a weak mineralocorticoid, to levels of physiological significance. Nevertheless, we observed neither antinatriuresis nor kaliuresis in ACTH-treated mice and plasma renin activity was not suppressed. We identified no changes in expression of mineralocorticoid target genes. Water turnover was increased in chronic ACTH-treated mice, as was hematocrit and hypertonicity: volume contraction is consistent with high levels of glucocorticoid. ACTH-treated mice exhibited other signs of glucocorticoid excess, such as enhanced weight gain and involution of the thymus. We identified novel ACTH-induced changes in i) genes involved in vitamin D (Cyp27b1, Cyp24a1, Gc) and calcium metabolism (Sgk, Calb1, Trpv5) associated with calciuria and phosphaturia; ii) genes that would be predicted to desensitize the kidney to glucocorticoid action (Nr3c1, Hsd11b1, Fkbp5) and iii) genes encoding transporters of enzymes systems associated with xenobiotic metabolism and oxidative stress. Although there is evidence that ACTH-induced hypertension is a function of physiological cross talk between glucocorticoids and mineralocorticoids, the present study suggest that the major changes in electrolyte and fluid homeostasis and renal function are attributable to glucocorticoids. The calcium and organic anion metabolism pathways that are affected by ACTH may explain some of the known adverse effects associated with glucocorticoid excess.Item Raised salivary testosterone in women is associated with increased attraction to masculine faces(Elsevier, 2007-08) Welling, L.; Jones, B.; Debruine, L.; Conway, C. A.; Lawsmith, M.; Little, A.; Feinberg, D.; Sharp, M. A.; Al-Dujaili, Emad A. S.Women's preferences for masculinity in men's faces, voices and behavioral displays change during the menstrual cycle and are strongest around ovulation. While previous findings suggest that change in progesterone level is an important hormonal mechanism for such variation, it is likely that changes in the levels of other hormones will also contribute to cyclic variation in masculinity preferences. Here we compared women's preferences for masculine faces at two points in the menstrual cycle where women differed in salivary testosterone, but not in salivary progesterone or estrogen. Preferences for masculinity were strongest when women's testosterone levels were relatively high. Our findings complement those from previous studies that show systematic variation in masculinity preferences during the menstrual cycle and suggest that change in testosterone level may play an important role in cyclic shifts in women's preferences for masculine traits.Item Effect of meal fat content on salivary testosterone and cortisol levels in healthy female volunteers(2005) Al-Dujaili, Emad A. S.; Bryant, M. L.The aim of this study was to determine if a change in the amount of fat consumed in the diet influenced female salivary postprandial testosterone and cortisol concentrations and whether any changes affected circadian rhythm. The study was conducted on 9 healthy female subjects aged 21-45 years (BMI mean=22.51.61) and has been approved by the University College Ethical Committee. Over 3 non-consecutive days, each subject consumed 2 meals, lunch and evening dinner, containing either, high fat (40-45% of total energy), low fat (20-25% of total energy), or the subjects usual daily meals. Saliva samples were collected at 11 predetermined times during the challenge days. Testosterone and cortisol levels in each sample were measured by specific and sensitive ELISA methods following ether extraction of saliva samples. Paired t-tests and repeated measures ANOVA were used for statistical analyses. On high fat diet, testosterone levels post lunch rose from a mean of 155 to 307 pg/ml.Testosterone results were significantly higher on the high fat diet compared to usual daily diet (p=0.018 at 30 minutes post-lunch, and p=0.006 at 1 hour post-lunch). Testosterone levels on low and high fat diets differed significantly 30 minutes post-lunch (p <0.05) and 5 minutes pre-dinner (p=0.03). There was a slight rise, though not significant, in testosterone level post dinner (From a mean of 136 to 189 pg/ml, p=0.22) on high fat content compared with a drop on low fat meal (from a mean of 212 pg/ml to 78 pg/ml). Cortisol levels on the low fat meal differed significantly from the high fat meal at1 hour and 2 hours post lunch (p<0.05 and p<0.01 respectively) and 2 hours post-dinner (p=0.041). Mean cortisol level on high fat meal rose from a mean of 3.34 to 4.935 ng/ml post lunch, with a smaller increase after evening meal (from 2.402 to 3.641 ng/ml). The findings of this study indicate that the amount of fat consumed in a meal, can influence postprandial levels of salivary testosterone and cortisol and their circadian rhythm profile. Such an effect on steroid hormones might have an impact on the person's daily activities and general health and wellbeing.
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