Relability of Animal Models In Biomedical Research: A Word of Caution

      Man had purely relied on observation to study complex physiologic principles for long with hardly any intervention possible. But ever since scientists started using animal models as human replicas, it has been possible to employ a lot of interventional and experimental strategies. Spontaneously hypertensive rat (SHR) is considered as one of the best and most widely used models of human hypertension. We have shown that acidosis induces a contraction in aortas from SHR and normotensive Wistar-Kyoto (WKY) rats. Since acidosis is not an uncommon condition in the setting of diabetes mellitus and chronic renal failure, which are often co-morbid with hypertension, this change in the behavior of arterial contractility was of immense interest. These findings in rodent animal model compelled us to investigate further the underlying mechanisms and the intracellular signaling pathways involved in contraction. However, much to our surprise, when the similar experiments were repeated on human (both normotensive as well as hypertensive) internal mammary artery, acidosis caused relaxation of vessels. Although SHR is a valuable model of hypertension, its findings were not reproducible in humans. Personal experience and review of literature shows lot of discrepancies between the data generated from humans and animals. However, it is a usual practice that the results obtained from animal models are extrapolated on humans. In this presentation, this issue will be focused, that while animal models are essential for the research and development, a critical caution needs to be practiced in interpreting the results. Uncritical reliance on the results of animal experimentation can be dangerously misleading and has resulted in damages to human health in several cases. This presentation will also discuss the role of certain confounding factors in using animal models.