Hello everyone,
I’d appreciate your input on an issue we’re facing in our rat myocardial infarction (MI) model.
We perform LAD ligation followed by 30 minutes of ischemia and 120 minutes of reperfusion. However, none of the animals survive the full reperfusion period. We observe persistent hemodynamic instability and spontaneous breathing efforts, despite using a new, functioning ventilator. We’ve tried settings of 1.0 ml/100 g BW at 60 BPM and 1.2 ml/100 g at 56 BPM. Core temperature is maintained via heating pad with rectal monitoring.
One factor that concerns me: all animals are non-pedigreed, inbred rats, bred in our facility without introducing new genetic material for over 5 years.
Could inbreeding be a contributing factor to this instability and poor survival? Has anyone encountered similar outcomes in aged inbred colonies or have suggestions for troubleshooting?
Thanks in advance for your thoughts!
Thank you for raising this, it's a valid concern worth exploring. Inbreeding can significantly impact the physiological resilience and variability in animal models. In a rat MI model, reduced genetic diversity may lead to compromised cardiovascular function, impaired stress response, and increased susceptibility to arrhythmias or heart failure post-MI. This could partly explain the observed haemodynamic instability and poor survival rates.
I’d suggest reviewing the colony's breeding history and comparing with outbred or hybrid strains, if possible. Introducing some genetic variability could help improve model reliability and better mimic human disease outcomes.
Has anyone compared survival or haemodynamic profiles between different rat strains in similar MI settings?
Y malaysia