Intermittent Exposure to Chlorpyrifos Differentially Impacts Neuroreflex Control of Cardiorespiratory Function in Rats.

Intermittent Exposure to Chlorpyrifos Differentially Impacts Neuroreflex Control of Cardiorespiratory Function in Rats. Cardiovasc Toxicol. 2019 May 16;: Authors: Batista TJ, Minassa VS, Aitken AV, Jara BT, Felippe ISA, Beijamini V, Paton JFR, Dos Santos L, Sampaio KN Abstract Previous studies showed that chlorpyrifos (CPF) acute exposure impaired cardiorespiratory reflexes. Evidence also indicates that continuous exposure to organophosphorus compounds impairs cardiovascular function. However, the effect of intermittent exposure to CPF, as may be experienced in the real world, on tonic and reflex cardiorespiratory function remains unexplored. Wistar rats were injected with saline or CPF for 4 weeks (3 times/week) or 12 weeks (once/week) at the doses of 7 mg/kg and 10 mg/kg. After exposure, blood pressure (BP), heart rate (HR), respiratory rate (fR), tidal volume (VT), and minute volume (VE) were recorded. Systolic BP and pulse interval (PI) variability, HR spectrum, spontaneous baroreflex and chemoreflex function were also evaluated. Plasma butyrylcholinesterase and brainstem acetylcholinesterase activities were quantified. Enzymatic activity of the CPF animals was reduced after both treatment periods. Baseline BP, HR, and fR, as well as systolic BP and PI variability indices, did not change, after CPF treatment. VT and VE were elevated in CPF animals. CPF exposure increased the very low-frequency component of the HR spectrum. Ba...
Source: Cardiovascular Toxicology - Category: Cardiology Authors: Tags: Cardiovasc Toxicol Source Type: research