Application of animal models in experimental medicine on the basis of pulmonary hypertension

Pulmonary hypertension (PH) is a rare disorder with a severe course. Despite significant progress in diagnosis and therapy, PH is an incurable disease with a high mortality rate. Current pharmacotherapy improves the patient's quality of life and prolongs his/her longevity, but it does not completely reverse pathological and haemodynamic changes. This might result from the multifactorial pathomechanism of the disease, which includes multiple signaling pathways. There is a need to develop novel therapies. In order to achieve this purpose, preclinical experiments are made, for instance, on animal models. Identification of potentially effective substances for further evaluation in clinical trials is determined by a variety of factors, including the selection of an appropriate test model. An ideal animal model that fully reflects the human form of pulmonary hypertension has not been identified, as yet. Generally, studies are conducted on classical models, including the chronic hypoxia model (CH) and monocrotaline model (MCT). This study presents selected animal models of pulmonary hypertension, which are used in efficiency tests on potentially new drugs as well as a mechanism of action of PH inductors and both haemodynamic and histopathological changes, characteristic for each model. The technique and conditions for the induction of pulmonary hypertension are discussed for selected methods. The authors emphasized interspecific differences in experimental animals. The article also summarizes potential benefits and limitations of animal models of pulmonary hypertension in preclinical studies, with consideration given to the repeatability and predictability of results, the cost of experiments, the toxicity of PH inductors and the comparability between haemodynamic and histopathological changes, induced in animals, and changes in the clinical picture of pulmonary hypertension in humans.