Related Experiment Video
Updated: Mar 15, 2026

Enrichment of Mammalian Tissues and Xenopus Oocytes with Cholesterol
Published on: March 25, 2020
Distinct mechanisms underlying cholesterol protection against alcohol-induced BK channel inhibition and resulting
Shivantika Bisen1, Olga Seleverstov1, Jitendra Belani2
1Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA.
Abstract:
Alcohol (ethanol) at concentrations reached in blood following moderate to heavy drinking (30-80mM) reduces cerebral artery diameter via inhibition of voltage- and calcium-gated potassium channels of large conductance (BK) in cerebral artery smooth muscle. These channels consist of channel-forming α and regulatory β1 subunits. A high-cholesterol diet protects against ethanol-induced constriction via accumulation of cholesterol within the vasculature. The molecular mechanisms of this protection remain unknown. In the present work, we demonstrate that in vitro cholesterol enrichment of rat middle cerebral arteries significantly increased cholesterol within arterial tissues and blunted constriction by 50mM of ethanol. Ethanol-induced BK channel inhibition in inside-out patches excised from freshly isolated cerebral artery myocytes was also abolished by cholesterol enrichment. Enrichment of arteries with enantiomeric cholesterol (ent-cholesterol) also blunted BK channel inhibition and cerebral artery constriction in response to ethanol. The similar protection of cholesterol and ent-cholesterol against ethanol action indicates that this protection does not require protein site(s) that specifically sense natural cholesterol. Cholesterol-driven protection against ethanol-induced BK channel inhibition and vasoconstriction was replicated in myocytes and middle cerebral arteries of C57BL/6 mice. BK β1 subunits are known to regulate vascular diameter and its modification by ethanol. However, blunting of an ethanol effect by in vitro cholesterol enrichment was observed in arteries and myocyte membrane patches from BK β1 (KCNMB1) knockout mice. Thus, BK β1 subunits are not needed for cholesterol protection against ethanol effect on BK channel function and cerebral artery diameter.
Related Concept Videos
Cholesterol: Significance and Regulation
Considering cholesterol and...
Indirect-Acting Cholinergic Agonists: Mechanism of Action
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex,...
Lipid-Lowering Drugs: Statins and Miscellaneous Agents
Protection of Alcohols
Protection
It defines a protecting group as the masking agent to make the more reactive species inert to a given set of conditions. This concept is depicted via the illustration of liquid flow through different outlets in an assembly of pipes. The analogy helps to understand the role...
Antihypertensive Drugs: Action of Calcium Channel Blockers
Protecting Groups for Aldehydes and Ketones: Introduction

