A novel hypertensive crisis rat model established by excessive norepinephrine infusion and the potential therapeutic effects of Rho-kinase inhibitors on it.

Hypertension crisis is a severe disease and needs emergency treatment in clinic. It is an important task to discover novel drugs which could lower the blood pressure steadily and quickly. However, animal models for screening anti-hypertensive crisis agents are unsatisfactory. The present study aimed to establish a new hypertensive crisis rat model and then explore the therapeutic effects of three Rho-kinase inhibitors including Fasudil, DL0805-1 and DL0805-2 on such a disease model. The hypertensive crisis symptoms were developed on male Wistar rats by subcutaneously injecting small doses of norepinephrine (NE) for 10 days in the initial stage. A sudden increase in blood pressure (BP) was then induced by excessive NE infusion. Compounds to be tested were intravenously injected into the rats immediately when the rapidly increased systolic blood pressure appeared. The results have shown that after small dose administration with NE, the rats could obtain acute BP increase to a high level without sudden death when a large dose of NE was injected. Fasudil, DL0805-1 and DL0805-2 could lower the blood pressure quickly in a dose dependent manner and improve the survival rate. The compounds also prevent the animals from organ damage. In conclusion, we established a novel hypertensive crisis animal model which could evaluate agents within a short time. In this model, we found that three Rho-kinase inhibitors have potential therapeutic effects on hypertensive crisis. This work might contribute to the discovery and development of new anti-hypertensive crisis drugs.