[Vascular irritability study of montirelin hydrate (NS-3) injection in rabbits]

A vascular irritability study of montirelin hydrate (NS-3) injection, a new drug for the treatment of disturbance of consciousness, was conducted in Japanese white rabbits. The concentration of montirelin hydrate was 4 mg/ml. Saline and 0.75% acetic acid were used as negative and positive control, respectively. In a part of the ear vein, 0.05 ml of each compound was allowed to remain for 3 min after intravenous injections once a day for 8 days. Inflammation in peri-venous region and thrombus were macroscopically observed in injection sites of rabbits with the montirelin hydrate injection group. However, no changes were seen with the negative control group. Histopathological examination revealed periphlebitis, desquamation of endothelial cells and thrombus in rabbits given montirelin hydrate injection or saline. But incidence and degree of periphlebitis caused by montirelin hydrate injection were higher than those caused by saline. On the other hand, the irritating changes caused by 0.75% acetic acid were severer than those by montirelin hydrate injection. These results show that montirelin hydrate injection has a very weak vascular irritability in the ear of rabbits.