Cardiac autonomic regulation after lung exposure to carbon nanotubes

• Published in: Human & experimental toxicology 2009-06, Vol.28 (6-7), p.369-375
• Main Authors: Legramante, JM, Valentini, F., Magrini, A., Palleschi, G., Sacco, S., Iavicoli, I., Pallante, M., Moscone, D., Galante, A., Bergamaschi, E., Bergamaschi, A., Pietroiusti, A.
• Format: Article
• Language: English
• Subjects: Animals; Baroreflex; Carbon; Cardiovascular system; Female; Health risk assessment; Heart - physiology; Human exposure; Lung - drug effects; Male; Nanotubes; Nanotubes, Carbon; Occupational health; Rats; Rats, Inbred WKY; Respiratory system; Toxicology
• ISSN: 0960-3271; 1477-0903
• DOI: 10.1177/0960327109105150

The ultrafine (UF) component of airborne pollution may impair cardiovascular autonomic control, a high-risk condition for cardiovascular adverse events. Since engineered nanoparticles, such as single-walled carbon nanotubes (SWCNTs) share physicochemical properties with UF, they might have similar adverse effects. Aim of the study was to evaluate arterial baroreflex function (BRF) at baseline, 24 h after the first instillation, immediately before the second one, and 2 weeks later, in adult Wystar-Kyoto conscious rats undergoing two intratracheal instillations of SWCNT (eight rats) or phosphate buffer saline (PBS) (five rats) at 2-week interval. During each session, 30-min continuous recording of arterial pressure and pulse interval was performed by a telemetered catheter implanted in the abdominal aorta of the rats. BRF was studied by the sequence technique. SWCNTs dispersed in PBS (1 mg/ml) were administered immediately after sonication (1 μg/g body weight). A significant decrease in the number of baroreflex sequences (from 498 ± 27.1 at baseline to 287 ± 40.2 at the recording performed after 4 weeks; P < 0.05) was observed in SWCNT-instilled rats, whereas no significant change was detected in controls. These data suggest that SWCNTs may alter the BRF, thus affecting the autonomic cardiovascular control regulation.