Combinatorial effect of nicotine and black tea on heart rate variability: Useful or harmful?

The effect of nicotine on heart rate variability (HRV) is controversial. Autonomic nervous system is the main regulator of heart rhythm, and heart rate variability is an appropriate index to assessment of the effects of the autonomic system on heart. In this study, the combination effect of nicotine and black tea consumption on sympatho-vagal balance and heart rate variability was investigated in rats. Male Wistar rats were randomized into four groups as control, tea (2.5 g/100 cc, daily), nicotine (2 mg/kg/d) and tea plus nicotine groups which treated for 28 days, and in the 29th day, their electrocardiograms (lead II) were recorded. The mean of high-frequency power (HF) in tea, nicotine and tea plus nicotine groups was significantly more than control group (P < .05), and low-frequency power/high-frequency power (LF/HF) ratio in the nicotine and tea + nicotine groups was significantly less than control group (P < .05). LF values did not differ significantly among groups. Mean of standard deviation of normal RR intervals (SDNN) and square root of the mean squared differences of successive RR intervals (RMSSD) increased significantly in tea, nicotine and tea + nicotine groups in comparison with control group (P < .05) Overall, 4-week administration of black tea, nicotine or their combination with dosages used in this study can increase the heart rate variability and improve the sympatho-vagal balance in rat.

Low-intensity endurance exercise plus nandrolone decanoate modulates cardiac adiponectin and its receptors.

Vast adverse effects of anabolic-androgenic steroids (AASs) on athletes' cardiovascular systems have been reported. However, there is still a lack of adequate information regarding the pathways and mechanisms involved. We tested the hypothesis that adiponectin and its receptors in the heart may be affected by long-term use of AASs alongside exercising. Male Wistar rats were randomized into the control (CTL), exercise (EX), nandrolone (Nan), arachis (Arach) group which treated with arachis as vehicle, trained vehicle (EX+Arach) and trained nandrolone (EX+Nan) groups that were treated for 8 weeks. One day after the end of the protocol, animals were sacrificed and their hearts were frozen. TNF-α and adiponectin proteins of hearts were evaluated quantitatively by ELISA kits, and Western blot analysis was used for measuring adiponectin receptor protein expression. TNF-α protein increased significantly in the EX+Nan group (P<.05 vs CTL group). The AdipoR1 protein was significantly higher in the presence of nandrolone alongside exercise (P<.05 vs Nan and EX+Arach groups, P<.01 vs CTL and Arach groups). In addition, AdipoR2 protein enhanced in the EX+Nan group when compared with the other groups (P<.05 vs EX and EX+Arach groups, P<.01 vs CTL, Arach and Nan groups). Chronic nandrolone plus mild endurance exercise may be associated with imbalance in pro-/anti-inflammatory cytokines and may induce a positive modulatory effect on cardiac adiporeceptors in rat. Further studies are required before these findings can be generalized to humans.

Effect of Quercus infectoria and Rosa damascena on lipid profile and atherosclerotic plaque formation in rabbit model of hyperlipidemia.

Hyperlipidemia is the cause of many complications in the human societies. In this study, the effect of methanol extracts of Quercus infectoria (QI) galls and Rosa damascena (RD) Mill flower were studied on lipid profile and atherosclerotic plaques formation in hyperlipidemic rabbits. Thirty-six New Zeland white rabbits randomly divided into 6 groups as control (I), hyperlipidemic (II), hyperlipidemic+QI (III), hyperlipidemic+RD (IV), +Atorvastolin (V) and hyperlipidemic+Orlistat (VI) and were fed with high fat diet (0.5% cholesterol and 16% hydrogenated vegetable oil) for 45 days. At the end of the study period, lipid profile and plaque formation were assessed. Total Cholesterol (TC), Low Density Lipoprotein (LDL) and Triglyceride (TG) levels were significantly increased in hyperlipidemic group compared with control group (p < 0.001). Methanol extract consumption of Quercus infectoria significantly decreased plasma levels of TC, TG and LDL (p < 0.001). It also decreased plaques formation in semi lunar valve and thoracic aorta. Rosa damascena mill flower methanol extract moderately decreased the levels of TC, TG, LDL and plaques formation but it was not significant. HDL levels and weight of animals did not show significant difference among groups. Based on the doses used in this study, our finding indicated that QI but no RD methanol extract has anti atherogenic and hypolipidemic activities.

Canine visceral leishmaniasis in boyer ahmad district, kohgiluyeh & boyer ahmad province, southwest of iran.

BACKGROUND: Mediterranean type of visceral leishmaniasis (VL) is present in different parts of Iran. Several studies have identified dogs as the main reservoirs of the VL caused by Leishmania infantum in Iran and other Mediterranean regions. This study aimed to determine the seroprevalence of canine visceral leishmaniasis as animal reservoir host for human visceral leishmaniasis in Boyer Ahmad district in southwest of Iran. METHODS: A seroepidemiological study was carried out to determine the seroprevalence of canine visceral leishmaniasis (CVL) among ownership dogs by using direct agglutination test (DAT) in 23 of 182 villages of Boyer Ahmad district, during August 2009 to August 2010. One hundred and seventy serum samples from ownership dogs were selected by multi-stage cluster sampling in villages of Boyer Ahmad district. All samples were tested by DAT and anti-Leishmania antibodies titers at ≥ 1:320 was considered as positive. RESULTS: Of the 170 serum samples, 10% were positive by DAT at titers of 1:320 and higher. No statistical significant difference was found between male (10.7%) and female (8.3%) seroprevalence. The highest seroprevalence rate (15.1%) was observed among the ownership dogs of four to seven years age. Altogether, seventeen (25.4%) of the seropositive dogs had clinical signs and symptoms. CONCLUSION: It seems that Boyer Ahmad district is an endemic area for canine visceral leishmaniasis in Iran.