Metabolic Disorders Induced by Fructosedrinking Water Affect Angiotensin II-mediated Intestinal Contractility in Male Wistar Rats.

INTRODUCTION: The high-fructose diet in rats has been reported to cause metabolic disorders such as impaired fasting glucose levels, in-sulin resistance, dyslipidemia, and dysregulation of the renin-angiotensin system. This could lead to further complications, for instance, to the smooth muscle dysfunction. AIM: The present study aimed at developing fructose-induced metabolic perturbations in rats and the investigation of their impact on angiotensin II-induced smooth muscle intestinal motility. MATERIALS AND METHODS: Mature Wistar rats were randomly divided into two groups (9 rats per group): control group (drinking tap water) and fructose-drinking group (15% fructose, dissolved in tap water). At the end of the experimental period (11 weeks), the plasma levels of insulin, renin, angiotensin II and creatinine, as well as the lipid profile were assessed. Morphometric analysis and lipid index calculation were also performed. The contractile properties of ileum, colon and rectum were studied using stimulation with angiotensin II in the isolated tissue bath system. RESULTS: Our experiment showed that drinking 15% fructose solution induced dyslipidaemia accompanied by elevated lipid indexes as well as an increase in creatinine and renin plasma levels in the rats. CONCLUSIONS: Fructose drinking and consequently the developed metabolic disorders modified the Ang II-induced intestinal activity causing a gradual alteration in the distal direction with the rectum being the most strongly affected organ.

Metabolic disturbances in women with polycystic ovary syndrome.

The AIM of the study was to characterize the metabolic syndrome in lean and overweight women with polycystic ovary syndrome (PCOS). The study included 142 premenopausal women distributed into 2 subgroups according to the body mass index: Group 1 with normal weight (n = 39) and Group 2 with overweight (n = 103). The following parameters were measured: basal and oral glucose tolerance test (oGTT)-induced glucose, insulin and triglycerides (TG1), glycated hemoglobin, total, HDL- and LDL-cholesterol; HOMA index and 2 indices of atherogenic risk (total/HDL-cholesterol and atherogenic index) were calculated. The results were compared with those of 35 clinically healthy women allocated also to 2 subgroups: Group 3 with normal weight (n = 18) and Group 4 with overweight (n = 17). Group 1 differed from group 3 in significantly higher fasting, 120-minute insulin, 180-minute insulin during the oGTT, fasting and stimulated TG1, and atherogenic index. Group 2 did not differ from group 4 in the lipid parameters, but 60-minute, and 120-minute glucose, the area under the curve (AUC) of glucose, and stimulated insulin were significantly higher at similar levels of fasting insulin, homeostasis model assessment (HOMA) index and glucose-to-insulin ratio. Fasting glucose did not differ between the two subgroups of PCOS women, but 60-minute, and 120-minute glucose, AUC glu, fasting, 60-minute, and 180-minute insulin, AUC ins and HOMA index were significantly higher in group 2 where the lipid parameters were significantly unfavourable. Our data confirmed the presence of insulin resistance of various degree and an increased lipid atherogenic risk in PCOS while obesity appeared as an additional factor aggravating the metabolic disturbances.

Role of 24-hour monitoring in assessing blood pressure changes in polycystic ovary syndrome.

INTRODUCTION: Polycystic ovary syndrome (PCOS) is associated with higher risk of developing cardiovascular diseases including higher incidence of hypertension later in life. Absence of circadian blood pressure fluctuations is considered as a marker of pre-hypertensive state and correlates highly with target organ damage in hypertension. AIM: Characterization of the circadian blood pressure rhythms as well as comparison of the results from the clinical measurements and Holter-monitored blood pressure data in women with PCOS. MATERIALS AND METHODS: The study comprised 35 women (mean age 22.6 +/- 5.9 years, mean BMI 31.4 +/- 7.1 kg/m2) with proven diagnosis. 24-hour ambulatory Holter-monitoring using Oscar device (Sun Tech Medical Instruments, USA) was performed in parallel with clinical measurements of blood pressure. RESULTS: There were 25.7% of the subjects diagnosed with hypertension according to the criteria of ambulatory monitoring observing discrepancy with the criteria for normal clinically measured blood pressure in 7 cases (20%). The "white coat" effect was observed in 11.4%. Physiological nocturnal drop in the systolic pressure was not observed in 51.4% of the patients and in the diastolic pressure - in 22.9% of the cases. CONCLUSIONS: The results confirm the advantages and the importance of the 24-hour monitoring as a diagnostic and predictive method for assessment of blood pressure alterations even in the absence of overt hypertension. PCOS is characterized by higher incidence of unstable blood pressure that is an additional risk factor for further development of cardiovascular diseases in this relatively young age group.

Enzymatic toxins from snake venom: structural characterization and mechanism of catalysis.

Snake venoms are cocktails of enzymes and non-enzymatic proteins used for both the immobilization and digestion of prey. The most common snake venom enzymes include acetylcholinesterases, l-amino acid oxidases, serine proteinases, metalloproteinases and phospholipases A(2) . Higher catalytic efficiency, thermal stability and resistance to proteolysis make these enzymes attractive models for biochemists, enzymologists and structural biologists. Here, we review the structures of these enzymes and describe their structure-based mechanisms of catalysis and inhibition. Some of the enzymes exist as protein complexes in the venom. Thus we also discuss the functional role of non-enzymatic subunits and the pharmacological effects of such protein complexes. The structures of inhibitor-enzyme complexes provide ideal platforms for the design of potent inhibitors which are useful in the development of prototypes and lead compounds with potential therapeutic applications.