The guinea pig as an animal model for studying perinatal changes in microvascular function

Introduction: Microvascular dysfunction, characterized by inappropriate vasodilatation and high blood flow in the peripheral microcirculation, is linked to physiologic instability and poor outcome in neonates. Specifically, preterm neonates have significantly higher levels of baseline microvascular blood flow than term neonates at 24 h postnatal age. Because of similarities between human and guinea pig endocrine profiles and maturity at birth, we hypothesized that preterm guinea pig neonates would provide a suitable model for studying the mechanisms underlying transitional microvascular function. Results: Guinea pigs that were delivered preterm showed immaturity and had markedly reduced viability. Baseline microvascular blood flow was significantly higher in preterm animals than in term animals. No effect of intrauterine growth restriction or birth weight on baseline microvascular blood flow was observed in either preterm or term animals. Discussion: These results are consistent with recent clinical findings and support the use of the guinea pig as a suitable model for future studies of the mechanisms underlying perinatal microvascular behavior. Methods: Guinea pigs were delivered either prematurely or at term. Laser Doppler flowmetry was used to study microvascular blood flow at 23 h postnatal age.