Effects of sidestream cigarette smoke exposure on baroreflex components in spontaneously hypertensive rats

Abstract

We evaluated short-term effects of sidestream cigarette smoke (SSCS) exposure on baroreflex function in spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKY) normotensive rats. Rats were exposed to SSCS during three weeks, 180 min, five days per week, in a concentration of carbon monoxide (CO) between 100 and 300 ppm. We observed that SSCS exposure increased tachycardic peak and heart rate range while it attenuated bradycardic reflex in WKY. In respect to SHR, SSCS also increased tachycardic peak. Taken together, our data suggests that three weeks of exposure to SSCS affects the sympathetic and parasympathetic component of the baroreflex in normotensive WKY while it tended to affect the sympathetic component in SHR.

Cardiovascular Responses Induced by Catalase Inhibitior into the Fourth Cerebral Ventricle Is Changed in Wistar Rats Exposed to Sidestream Cigarette Smoke

“…The intravenous sodium nitroprusside decreases arterial blood pressure and activates the sympathetic nervous system, leading to the tachycardic reflex. (21,24,28) The difference between the results from this study and the other reported in Wistar rats regarding autonomic cardiac responses to SSCS is possible due to the difference between WKY and Wistar rats, since WKY rats come from normotensive strains of SHR. (27) The novelty of this study is the protocol of the analysis of cardiovascular responses induced y catalase inhibition into the 4 th cerebral ventricle.…”

“…Control animals maintained at the same place and same conditions as the SSCS group but exposed to fresh air. (19)(20)(21) …”

“…Cannulas were fixed to the skull with dental cement and one metal screw. (22,23) One day before the experiments, rats were anesthetized with ketamine (50 mg/kg i.p.) and xylazine (50 mg/kg i.m.)…”

Tabagismo: o que tem sido abordado em periódicos brasileiros

“…At the end of the period, the exposed group showed higher incidences of concentric and eccentric myocardial hypertrophy shown at the echocardiography. Another study designed to evaluate the cardiovascular impact of a less prolonged exposure (3 weeks) of mice to pollution showed no differences in the studied variables (blood pressure, heart rate, heart rate variability and baroreflex response to nitroprusside stimulus) between the exposed and non-exposed group 52 . Justo et al 53 evaluated in young rats, whether the use of stimulant drugs such as methylphenidate (MPH), could facilitate the nicotine addiction, as suggested by some studies in humans.…”

What Has Taught Almost Half A Century of Research on the Relationship Between Passive Smoking and Cardiovascular System?

“…Therefore, an unpromising future will affect all those individuals exposed, against their will, to the harmful effects of passive smoking and, consequently, all the forces in the field of health, policy and the socioeconomic structures should defeat the contemporary plague of cigarette smoking in all its forms. Indeed, the harm caused by smoking is demonstrated by studies either clinically or related experimentally in exposed animals [62][63][64][65].…”