Biotransformation enzymes and their induction by beta-naphthoflavone in adult sea bass (Dicentrarchus labrax)

In the present study we have determined for the first time the hepatic activities of several microsomal P-450 dependent monooxygenases including the testosterone hydroxylase and the Ah-receptor gene battery-related phase II enzymes [UDP-glucuronyl transferase (UDP-GT), DT-diaphorase, glutathione S-transferase, aldehyde dehydrogenases] in adult sea bass (300-400 g). We also investigated the effect of beta-naphtoflavone (beta-NF) on these enzymes to assess their potential as biomarkers of polycyclic aromatic hydrocarbon exposure. beta-NF. administered to fish with a single i.p. injection at various doses, resulted in an induction in the liver of the P-450 1A, as immunodetected by anti rat P-450 1A1 antibodies, P-450 1A-linked ethoxyresorufin-O-deethylase (EROD) and methoxyresorufin-O-demethylase (MEROD) activities. Among the phase II enzymes only the phenol UDP-GT was induced in liver by beta-NF. The time course of these inductions exhibited different patterns. EROD and MEROD activities reached a peak value 3 days post-injection and maintained values significantly above the corresponding control activities over the 30 days of the experiment, the phenol UDP-GT activity peaked at dap 8 and afterwards declined rapidly achieving the control value 18 days post-injection. A treatment of 80 mg kg(-1) beta-NF increased the immunodetectable P-450 1A apoprotein and EROD, but not MEROD, activity in extrahepatic tissues such as, gill, kidney and olfactory rosettes. Taken overall, the results indicate that MEROD. EROD and phenol UDP-GT activities may be useful biomarkers for the exposure of adult sea bass to polycyclic aromatic hydrocarbons. (C) 1998 Elsevier Science B.V. All rights reserved

Body Weights (g ± SEM) n = 8-10/group.

<p>Body Weights (g ± SEM) n = 8-10/group.</p

Snoring, hypertension and type 2 diabetes in obesity. Protection by physical activity

ABSTRACT Sleep-related breathing disorders are recognized as major health problems in obesity. They are involved in both hypertension and type 2 diabetes, through mechanism(s) possibly related to increased sympathetic tone. We studied the association of habitual snoring with diabetes, hypertension, weight cycling and physical activity in a large Italian database of treatment-seeking obese subjects. Clinical and behavioural data were assessed by standardized questionnaires. Consecutive data of 1890 obese patients were analysed (average BMI, 38.2 kg/m2, median age 46 years, 78% females), from 25 obesity Italian centres, with low prevalence of clinical manifestations of cardiovascular disease. Habitual snoring was reported in 56% of cases, and was associated with day-time sleepiness. The prevalence increased with obesity class and waist circumference, and was positively associated with weight cycling and weight gain since age 20 years, and smoking. Regular physical activity had a protective effect. Snoring was associated with diabetes and hypertension at univariate analysis, but in multivariate analysis an independent effect was only observed for hypertension. After adjustment for age, gender and BMI, physical activity maintained an independent, protective effect on both snoring (odds ratio 0.65, 95% confidence interval 0.49 – 0.84; P = 0.001), diabetes (0.50, 0.30 – 0.86; P = 0.011) and hypertension (0.71, 0.53 – 0.95; P = 0.023). We conclude that in treatment-seeking, obese subjects with low prevalence of cardiovascular disease, snoring independently increases the risk of hypertension, whereas physical activity exerts a protective on both snoring and complications. These data underline the importance of lifestyle interventions to limit the burden of obesity and associated diseases

Influence functions of two families of robust estimators under proportional scatter matrices

Robust estimation, Robust scatter matrices, Projection-pursuit, Proportional scatter models, Partial influence curves,