title: Acute changes in pulmonary function following microinstillation inhalation exposure to soman in nonatropenized guinea pigs.
abstract: Barometric whole-body plethysmography (WBP) was used to examine pulmonary functions at 4 and 24 hours postexposure to soman (GD) in guinea pigs without therapeutics to improve survival. Endotracheal aerosolization by microinstillation was used to administer GD (280, 561, and 841 mg/m(3)) or saline to anesthetized guinea pigs. Significant increases in respiratory frequency (RF), tidal volume (TV), and minute volume (MV) were observed with 841 mg/m(3) GD at 4 hours and that were reduced at 24 hours postexposure. A dose-dependent increase in peak inspiration flow and peak expiration flow was present at 4-hour post-GD exposure that was reduced at 24 hours. Time of inspiration and expiration were decreased in all doses of GD exposure at 4 and 24 hours, with significant inhibition at 841 mg/m(3). End-expiratory pause (EEP) increased at 280 and 561 mg/m(3), but decreased in animals exposed 841 mg/m(3) at 24 hours postexposure. Pseudo-lung resistance (Penh) and pause followed similar patterns and increased at 4 hours, but decreased at 24 hours postexposure to 841 mg/m(3) of GD compared to control. These studies indicate GD exposure induces dose-dependent changes in pulmonary function that are significant at 841 mg/m(3) at 4 hours and remains 24 hours postexposure. Furthermore, at 4 hours, GD induces bronchoconstriction possibly due to copious airway secretion and ongoing lung injury in addition to cholinergic effects, while at 24 hours GD induces bronchodilation a possible consequence of initial compensatory mechanisms.
authors.affiliation: US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, USA.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Perkins
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Pierre
authors.forename: Peter
authors.initials: P
authors.lastname: Rezk
authors.forename: Jian
authors.initials: J
authors.lastname: Song
authors.forename: Samuel
authors.initials: S
authors.lastname: Oguntayo
authors.forename: Alfred M
authors.initials: AM
authors.lastname: Sciuto
authors.forename: Bhupendra P
authors.initials: BP
authors.lastname: Doctor
authors.forename: Madhusoodana P
authors.initials: MP
authors.lastname: Nambiar
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002619:Chemical Warfare Agents / Q000633:toxicity*; D006168:Guinea Pigs; D008168:Lung / Q000187:drug effects* / Q000502:physiology; D010991:Plethysmography; D012129:Respiratory Function Tests; D012999:Soman / Q000633:toxicity*
chemical_list: D002619:Chemical Warfare Agents; D012999:Soman