Related Experiment Videos
Experimental studies with isradipine in stroke
Abstract:
The effects of isradipine in a rat model of embolic stroke [permanent occlusion of the left middle cerebral artery (MCA)] are reviewed. Isradipine, when present or given up to 4 hours after the onset of stroke, reduces the infarct size, determined by magnetic resonance imaging (MRI) 24 hours, and by histology 5 days, after MCA occlusion. These cytoprotective effects seem to be permanent and are paralleled by an improvement in the neurological deficit. Isradipine has proved to be the most potent and effective calcium antagonist for reducing the infarct size compared with other representatives of this class of drugs such as nimodipine, nicardipine and flunarizine. Isradipine is cytoprotective after a stroke when used as an antihypertensive: at doses which normalise high blood pressure in spontaneously hypertensive rats, isradipine reduces by more than 60% the infarct size caused by a subsequent stroke. Since the lowering of blood pressure, e.g. by a calcium antagonist that does not cross the blood-brain barrier, is ineffective in reducing the infarct size, normalisation of blood pressure alone cannot account for the reductions in infarct size observed with isradipine. The antihypertensive drug isradipine seems rather to offer the additional benefit of attenuating the consequences of an eventual stroke. If clinically confirmed, this will be of considerable therapeutic importance. Evidence is presented that isradipine has at least 2 mechanisms within the brain that might be responsible for cytoprotection in stroke.(ABSTRACT TRUNCATED AT 250 WORDS)
Insights
Isradipine effectively reduces stroke-related brain damage and neurological deficits in rats when administered shortly after an embolic stroke. This calcium channel blocker demonstrates potent cytoprotective effects, outperforming other drugs in reducing infarct size.
Area of Science:
- Neuroscience
- Pharmacology
- Cardiovascular Research
Background:
- Stroke remains a leading cause of disability and mortality worldwide.
- Effective treatments for acute ischemic stroke are limited, necessitating research into novel therapeutic agents.
- Calcium channel blockers are being investigated for their potential neuroprotective properties.
Purpose of the Study:
- To evaluate the efficacy of isradipine in reducing infarct size and improving neurological deficits in a rat model of embolic stroke.
- To compare the neuroprotective effects of isradipine with other calcium channel blockers.
- To explore the mechanisms underlying isradipine's cytoprotective effects in stroke.
Main Methods:
- Induction of permanent middle cerebral artery (MCA) occlusion in a rat model to simulate embolic stroke.
- Administration of isradipine at various time points (onset to 4 hours post-stroke).
- Assessment of infarct size using magnetic resonance imaging (MRI) and histology; evaluation of neurological deficits.
Main Results:
- Isradipine significantly reduced infarct size when administered up to 4 hours after MCA occlusion.
- Isradipine demonstrated superior efficacy in reducing infarct size compared to nimodipine, nicardipine, and flunarizine.
- Isradipine treatment led to a parallel improvement in neurological deficits.
- Isradipine, used as an antihypertensive, reduced infarct size by over 60% in spontaneously hypertensive rats, suggesting mechanisms beyond blood pressure normalization.
Conclusions:
- Isradipine exhibits potent cytoprotective effects in an embolic stroke model, reducing infarct size and improving neurological outcomes.
- Isradipine is a highly effective calcium channel blocker for stroke treatment, surpassing other agents in preclinical studies.
- The neuroprotective mechanisms of isradipine in stroke warrant further investigation, with potential clinical implications for stroke management.