Cardiac autonomic regulation after lung exposure to carbon nanotubes.
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 microg/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.
Legramante
J M
JM
Department of Internal Medicine, Tor Vergata University Rome, Italy.
Valentini
F
F
Magrini
A
A
Palleschi
G
G
Sacco
S
S
Iavicoli
I
I
Pallante
M
M
Moscone
D
D
Galante
A
A
Bergamaschi
E
E
Bergamaschi
A
A
Pietroiusti
A
A
D000818:Animals; D017704:Baroreflex; D005260:Female; D006321:Heart / Q000502:physiology*; D008168:Lung / Q000187:drug effects*; D008297:Male; D037742:Nanotubes, Carbon; D051381:Rats; D011921:Rats, Inbred WKY
D037742:Nanotubes, Carbon