Related Experiment Videos
[Microcirculation in the brain: viewpoint of autoregulation]
1Faculty of Pharmaceutical Sci., Medicinal Informatics and Research Unit, Fukuoka University, Japan.
Nihon Yakurigaku Zasshi. Folia Pharmacologica Japonica
|July 21, 1999
Summary
Cerebral blood flow autoregulation prevents dangerous pressure changes. Neurogenic factors and specific inhibitors abolish autoregulation breakthrough, suggesting a role in maintaining stable brain blood flow.
Area of Science:
- Neuroscience
- Physiology
- Cerebrovascular Regulation
Context:
- Cerebral blood flow (CBF) is tightly autoregulated to maintain stable perfusion.
- Breakthrough of autoregulation occurs when systemic blood pressure exceeds physiological limits, leading to increased CBF and decreased cerebrovascular resistance (CVR).
- Neurogenic factors and various endogenous substances significantly influence cerebral autoregulation.
Purpose:
- To investigate the mechanisms underlying the breakthrough of cerebral blood flow autoregulation.
- To identify neurogenic and pharmacological factors that modulate the autoregulatory response to hypertension.
- To elucidate the roles of vasodilators and vasoconstrictors in maintaining cerebral vascular tone.
Summary:
- The breakthrough of autoregulation is abolished by nitric oxide (NO) synthesis inhibitors, angiotensin converting enzyme inhibitors, prostanoids, sympathetic denervation, and sinoaortic denervation.
- This abolishment may result from increased cerebral vessel tolerance to hypertension or inhibited release of vasodilators like NO and prostanoids.
- Brain microvessel tone is regulated by cholinergic innervation, GABAergic and glutamatergic systems, and mediators such as NO, bradykinin, and PGs for dilation; and by norepinephrinergics, serotonergic, GABAergic, thromboxane, PGF2α, and angiotensin systems for constriction.
Impact:
- Understanding these mechanisms is crucial for preventing cerebral ischemia and hyperemia.
- Identifies key pathways involved in maintaining stable cerebral perfusion under varying blood pressures.
- Provides insights into potential therapeutic targets for cerebrovascular disorders.