Vasodilation Effects and Action Mechanisms of TMB-8 on Basilar Artery in Rabbits

Effects of Intracellular Calcium Reduction by Dantrolene on Prevention/Treatment of Ischemic Stroke

BACKGROUND: It has been suggested that cerebral blood vessels and brain cells might depend more on intracellular calcium than extracellular calcium to modulate intracellular free calcium concentrations, [Ca(2+)](i). METHODS AND RESULTS: A potent intracellular calcium antagonist, dantrolene, was used to prevent the ischemic stroke induced in the rat model. It was found that treatment of rats with dantrolene at -1 hour and +1 hour after 60 minutes of ischemic insult prevented by the formation of cortical necrosis 98% and 85%, respectively. Further, the [Ca(2+)](i) of embryonic aorta cells was markedly reduced, and cAMP of the same cultured cells were significantly increased by dantrolene treatment. CONCLUSIONS: These results indicate that ischemic stroke is preventable by dantrolene through reduction of [Ca(2+)](i) and increase of cAMP.

Antagonism of interleukin-1 (IL-1)-induced uveitis with synthetic IL-1 blockers

Because of the discovery of potent interleukin-1 (IL-1) blocking effects by CK-103A (4,6-dihydropyridazino[4,5-c]pyridazin-5 (1H)-ones) on rat uveitis induced by IL-1, numerous derivatives of CK-103A have been synthesized and their efficacies on the same animal model studied. The uveitis was induced by injection of 1 ng IL-1/10 microliters intravitreally. The inflammation reached peak at 12 hr after the injection of IL-1. The prevention/blockade of IL-1-induced uveitis was measured at this peak inflammation time point. It was found that 8 out of 12 CK-analogs studied produced an effective blockade of IL-1-induced uveitis. Most of them were at least equipotent or even more potent than prednisolone in blocking IL-1-induced uveitis. It is concluded that most dihydropyridazinopyridazin derivatives are effective anti-uveitis compounds. Some could be found to be safe and useful for the treatment of this dreadful disease.