Inflammatory cytokine response to injury in the aging rabbit subglottis.

Abstract

OBJECTIVES: We performed a pilot study to determine whether there is an age-related change in inflammatory expression in the subglottic mucosa of rabbits in response to a one-time injury. METHODS: Twenty-seven rabbits of 3 different ages meant to represent infant, adolescent, and adult stages underwent a unilateral, subglottic soft tissue injury. The animal groups were allowed to heal for 3 different durations to reflect the early, middle, and late stages of inflammation. Animal subglottises were then analyzed for quantitative differences in thickness and expression of multiple inflammatory cytokines within the soft tissue relative to the uninjured side. RESULTS: The animals in the youngest age group demonstrated a thickened-tissue response to injury yet a lower level of inflammatory cytokines than did the older animals at the early and middle stages of healing. CONCLUSIONS: Pronounced tissue thickness was an unanticipated finding in the youngest age groups and suggests better regulatory control by older animals. Also, a developmental difference in the inflammatory response to injury is suggested by the data.