Acute air particulate matter exposure triggers vascular dysfunction in senescent rats.

KURTZ, MELISA L; FERRARO, SEBASTÍAN; ROSSON, MARÍA INÉS ; ALVAREZ, LAURA; TASAT, DÉBORAH

Ciudad de Buenos Aires

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS- LXII REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA (SAIC); 2017

Epidemiological evidence supports an important association between air particulate matter (PM) exposure and cardiovascular risk. Acute 10 µg/m3 increase elevates cardiovascular mortality by 1%. Cardiovascular detrimental consequences due to PM could be explained by PM translocation from the respiratory epithelium towards circulation and next initiate cardiovascular toxicity. The aim of this study was to determine if pulmonary exposure to a PM surrogate, such as residual oil fly ash (ROFA), affects systemic vascular function. Objective: Evaluate vascular changes, lung, heart and aorta histology, blood smears and inflammatory serum cytokines after acute exposure to ROFA. M&M: Senescent (17 months old) female BDIX rats were divided in two groups and exposed by intranasal instillation to saline solution (Control) or ROFA 1mg//kg BW (ROFA). Euthanasia was performed 24h post-exposure and the respiratory tract, heart and aorta were excised, formalin fixed and process for routine histology. Previous to fixation a section of the aorta was placed in Krebs solution and cut into 3-4 mm wide rings. Rings vessel were suspended in a water-jacketed organ bath and the contractile response evaluated by cumulative noradrenaline (NA) addition (10-9 to 4x10-6 M) or Acetilcholine 10-6M (Ach). Complete blood count (CBC) was performed in blood smears. Serum TNFa, IL-6 and IL-10 levels were analyzed by ELISA. Results: Acute ROFA exposure induced histological changes in lungs and hearts and markedly systemic PMN augmentation when compared to Controls but no changes in cytokine levels between groups. Functionally, the maximal contractile response to NA increased in arteries from ROFA-exposed compared to Controls (39.4%, p