Validation of a new automatic smoking machine to study the effects of cigarette smoke in newborn lambs

Abstract

The aim of this study was to describe the characteristics and validate the use of a new, custom-built automatic smoking machine (ASM), primarily designed to study the effects of an environmental tobacco smoke surrogate (ETS surrogate) exposure in animals of various sizes, including large animals. The equipment includes a programmable ASM coupled to a vented whole body chamber, where animals can be exposed to both mainstream and sidestream smoke. The user-friendly interface allows for full programming of puff volume (1-60 mL), time interval between two puffs (1-60 s) and between two cigarettes (1-60 min). Eight newborn lambs were exposed to either 10 (4 lambs, C10 group) or 20 (4 lambs, C20 group) cigarettes, 8 h per day for 15 days. Four additional control, lambs were exposed to air (C0 group). Weight gain was identical in all three groups of lambs. Urinary cotinine/creatinine ratio increased with the number of cigarettes smoked (C0: 11 + 7 ng/mg; C10: 961 + 539 ng/mg; C20: 1821 + 312 ng/mg), with levels in the C10 and C20 groups in keeping with values published in infants exposed to ETS. Overall, results show that our new ASM is especially well suited for ETS surrogate exposure in nonrestrained, non-anaesthetized large animals such as sheep.

Reponse to Pfister R, Gyger M, Bugnon P, et al. Editorial ethical guidelines: what about the evaluation of the benefits to humans?

“…Authors, as acknowledged by Pfister et al, 4 are not publishing an entire programme of work but original data of novelty and incremental value to their field. Indeed, as indicated by Praud et al, 5 the wider context and implications of their publication in this journal were part of ethical review and the original paper clearly gives the societal and medical context for sudden infant death syndrome 3 and postnatal exposure.…”

“…Indeed, IAVE used the Laboratory Animals policy as the framework for its own initial proposals in 2008. For the review of the manuscript of Duvareille et al, 3 two independent peer reviews supporting publication were obtained and one of those reviews was undertaken by an expert in the contemporary application of UK regulations and ethical review.…”

Relevance of animal research on the effects of postnatal exposure to environmental tobacco smoke

“…As our recent publication on environmental tobacco smoke (ETS) exposure in lambs 2 was directly mentioned to exemplify their ethical issues, we are pleased to provide further information to relieve their concerns.…”

“…In our study under question, 2 we believe we made significant efforts to optimize animal utilization and wellbeing in the spirit of the 3Rs of Russell and Burch: 3 (1) Reduction: all lambs used in the ASM validation study reported in our publication 2 were simultaneously involved in another study on the effect of environmental smoke exposure on laryngeal chemoreflexes; 4 thus, lambs did not incur further procedure beyond those needed for the latter study. (2) Refinement: experimental exposure under close surveillance of our personnel, during daytime only, to detect any problem and ensure the animals' wellbeing; exposure of two animals together (animal enrichment) in a Plexiglas chamber fulfilling the CCAC rules for sheep, use of radiotelemetry to allow the study of freely moving lambs.…”

“…As a paediatric pulmonologist involved daily in the care of infants suffering from ETS consequences, as well as in the follow-up of ALTE infants and parents of all SIDS victims referred to our hospital, the senior author (JPP) has been actively engaged against ETS exposure for 30 years now. Furthermore, no co-authors of our publication 2 have any relationship of any kind whatsoever with the tobacco industry.…”