We thank Inoue and Takano (2017) for their interest in our article ‘Influence of inflammation and nitric oxide upon platelet aggregation following deposition of diesel exhaust particles in the airways’ (Smyth et al., 2017). They refer to our focus upon the effects of diesel exhaust particles (DEPs) upon platelet aggregation and highlight additional effects of DEP and diesel extract upon the coagulation system. Our focus on platelet aggregation was appropriate in our paper since the in vivo model used is driven by aggregation of platelets and their subsequent entrapment in the pulmonary vasculature, rather than the multifaceted models of thrombosis and coagulation employed elsewhere (Tymvios et al., 2008). Our paper therefore allows us to mechanistically link airways administration of DEP with subsequent platelet activation, which may explain the links between DEP exposure and the incidence of platelet driven cardiovascular events such as myocardial infarction. We agree with Inoue and Takano (2017) that there are additional and overlapping impacts of DEP upon other components of the cardiovascular system such as coagulation and, as shown in their 2006 publication (Inoue et al., 2006), these effects are likely to be particularly important against a background of lung inflammation.
An additional interesting point in the work of Inoue et al. (2006) is their use of DEP extracts and components to examine their impacts upon respiratory and cardiovascular health. This contrasts with our own approach in which we apply intact DEP with physicochemical properties that to some extent mimic those found in ambient air (Solomon et al., 2013). The use of physiological buffers for DEP suspension in our studies minimizes biological impacts by anything other than DEP.
In summary, our article and that of Inoue et al. (2006) provide complementary data sets suggesting that DEP has multiple impacts on cardiovascular health and that DEP is likely to act via a range of mechanisms to increase the risk of multiple cardiovascular events.
Conflict of interest
The authors declare no conflicts of interest.
Acknowledgements
M.E. and T.D.T were supported by a British Heart Foundation Project Grant (PG/10/80/28605).
Smyth, E. , Solomon, A. , Birrell, M. A. , Smallwood, M. J. , Winyard, P. G. , Tetley, T. D. , and Emerson, M. (2017) Response to ‘Effects of diesel exhaust particles on coagulation’. British Journal of Pharmacology, 174: 4200. doi: 10.1111/bph.14032.
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