Effects of physical exercise on baroreflex sensitivity and renal sympathetic nerve activity in chronic nicotine-treated rats

Sports activities and cardiovascular system change

Sports activity is generally considered to be beneficial to health. The World Health Organization (WHO) recommends physical activity as part of a healthy lifestyle. Sports activities significantly affect the cardiovascular system. A number of studies show that they significantly reduce the risk of cardiovascular disease as well as decrease cardiovascular mortality. This review discusses changes in various cardiovascular parameters in athletes - vagotonia/bradycardia, hypertrophy of heart, ECG changes, blood pressure, and variability of cardiovascular parameters. Because of its relationship to the cardiovascular system, VO2max, which is widely used as an indicator of cardiorespiratory fitness, is also discussed. The review concludes with a discussion of reactive oxygen species (ROS) and oxidative stress, particularly in relation to changes in the cardiovascular system in athletes. The review appropriately summarizes the above issues and points out some new implications.

Sympathetic and angiotensinergic activity in spontaneously hypertensive rats treated with 3-amino-1,2,4-triazole

Previous studies from our laboratory have shown that the pressor response to intracerebroventricular (icv) administered ANG II in normotensive rats or spontaneously hypertensive rats (SHRs) is attenuated by increased central H2O2 concentration, produced either by direct H2O2 icv injection or by increased endogenous H2O2 centrally in response to local catalase inhibition with 3-amino-1,2,4-triazole (ATZ). In the present study, we evaluated the effects of ATZ administered peripherally on arterial pressure and sympathetic and angiotensinergic activity in SHRs. Male SHRs weighing 280-330 g were used. Mean arterial pressure (MAP) and heart rate (HR) were recorded in conscious freely moving SHRs. Acute intravenous injection of ATZ (300 mg/kg of body weight) did not modify MAP and HR during the next 4 h, however, the treatment with ATZ (300 mg/kg of body weight twice per day) for 3 days reduced MAP (144 ± 6, vs. saline, 183 ± 13 mmHg), without changing HR. Intravenous hexamethonium (ganglionic blocker) produced a smaller decrease in MAP 4 h after ATZ (-25 ± 3, vs saline -38 ± 4 mmHg). Losartan (angiotensinergic AT1 receptor blocker) produced a significant depressor response 4 h after ATZ (-22 ± 4, vs. saline: -2 ± 4 mmHg) and in 3-day ATZ treated SHRs (-25 ± 5, vs. saline: -9 ± 4 mmHg). The results suggest that the treatment with ATZ reduces sympathetic activity in SHRs and simultaneously increases angiotensinergic activity.

Characterization and Summarization of the Impact of Electronic Cigarettes on the Cardiovascular System: A Systematic Review and Meta-Analysis

Electronic cigarettes may increase the risk of long-term cardiovascular morbidity. To protect the heart, awareness should be raised of the risks and limits of E-cigarette aerosol exposure. Thus, this systematic review and meta-analysis assessed the cardiovascular risk of e-smoking. This systematic review was conducted by using the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. We searched PubMed, Embase, Scopus, Web of Science, and Science Direct databases in December 2022 to identify studies investigating e-cigarettes' impact on the heart. The study was supported by meta-analysis and qualitative review. Out of the initial 493 papers, only 15 met the inclusion criteria and were included in the study. The cumulative number of participants in the myocardial infarction (MI) group was 85,420, and in the sympathetic groups in whom the systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP), and heart rate (HR) were measured, were 332 cigarette smokers. The control group included the "never use," "non-smokers," and "never smoke." The pooled analysis showed a significant difference between the e-cigarette smokers and the control group regarding the risk of developing MI in former smokers (OR= 0.12; 95% CI: 0.01-1.72, P = 0.12) and never smoked (OR= 0.02; 95% CI: 0.00-0.44, P = 0.01) favoring the control group. The pooled analysis of the included studies showed a significant difference between the e-cigarette smokers with nicotine and the control group regarding the mean difference (MD) of the SBP (MD = 2.89; 95% CI: 1.94-3.84; P < 0.001), the DBP (MD = 3.10; 95% CI: 0.42-5.78; P = 0.02), the MBP (MD = 7.05; 95% CI: 2.70-1.40; P = 0.001), and HF (MD = 3.13; 95% CI: 0.96-5.29; P = 0.005) favoring the control group. We conclude that using e-cigarettes has a detrimental effect on cardiac health. The risk of severe cardiac conditions increases with e-cigarettes. Thus, vaping can do more harm than good. Consequently, the misleading notion that e-cigarettes are less harmful should be challenged.