Related Experiment Video

Updated: Jul 16, 2026

Induction of Eryptosis in Red Blood Cells Using a Calcium Ionophore
09:15

Induction of Eryptosis in Red Blood Cells Using a Calcium Ionophore

Published on: January 21, 2020

The haemolytic effect of verapamil on erythrocytes exposed to varying osmolarity

T J Watts1, R D Handy

  • 1School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, United Kingdom. timwatts1984@yahoo.co.uk

Toxicology in Vitro : an International Journal Published in Association with BIBRA
|April 3, 2007
PubMed

The haemolytic effect of verapamil on red blood cells (RBCs) exposed to varying osmolarity was investigated. The experimental approach used a modified red cell haemolysis assay with concentrations of verapamil ranging from 50-1500 microM compared to drug free controls. The time-course of haemolytic effects was also investigated. We also briefly determined the haemolytic effects of verapamil in Ca2+-free conditions (with added EGTA). In conditions representing decreasing osmolarity (dilution from 140-0 mM NaCl) there was a significant increase in erythrocyte haemolysis that was also dependent on verapamil concentration (ANOVA, p<0.05). The red cells also showed a significantly increased rate of haemolysis over 5 h with increasing verapamil concentration (ANOVA, p<0.05). The degree of RBC hypotonic haemolysis was significantly increased in a Ca2+-free medium (+EGTA) compared to normal saline and this effect was exacerbated by additions of verapamil (ANOVA, p<0.05). Overall the data suggested that verapamil can cause haemolysis of RBCs in a predictable time- and concentration-dependent manner, and that verapamil increases the fragility of the erythrocytes further during hypotonic osmotic stress and Ca2+-free conditions. The mechanism of verapamil-dependent haemolysis could be directly related to the observed biphasic concentration-effect and could consequently involve several ion transport pathways.

More Related Videos

Measuring Deformability and Red Cell Heterogeneity in Blood by Ektacytometry09:12

Measuring Deformability and Red Cell Heterogeneity in Blood by Ektacytometry

Published on: January 12, 2018

Monitoring the Effect of Osmotic Stress on Secretory Vesicles and Exocytosis08:08

Monitoring the Effect of Osmotic Stress on Secretory Vesicles and Exocytosis

Published on: February 19, 2018

Related Concept Videos

Osmosis and Osmotic Pressure of Solutions02:40

Osmosis and Osmotic Pressure of Solutions

A number of natural and synthetic materials exhibit selective permeation, meaning that only molecules or ions of a certain size, shape, polarity, charge, and so forth, are capable of passing through (permeating) the material. Biological cell membranes provide elegant examples of selective permeation in nature, while dialysis tubing used to remove metabolic wastes from blood is a more simplistic technological example. Regardless of how they may be fabricated, these materials are generally...
Factors Influencing Microbial Growth: Osmolarity01:28

Factors Influencing Microbial Growth: Osmolarity

Osmolarity is the measure of solute concentration in a solution. It plays a critical role in determining water availability for organisms. Water moves across semipermeable membranes through osmosis, flowing from regions of lower solute concentration (more dilute) to regions of higher solute concentration (more concentrated).In high-solute environments, microbial cells lose water, leading to dehydration and inhibited growth. The extent to which water is available to microbes in such environments...
Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers01:20

Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers

Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation.
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Osmosis00:47

Osmosis

Approximately 60% to 95% of the weight of living organisms is attributed to water. Therefore, maintaining appropriate water balance within cells is of paramount importance. Osmosis is the movement of water across a semipermeable membrane, such as a cell’s plasma membrane. In living organisms, water plays a crucial role as a solvent—a molecule that dissolves other molecules.Diffusion Versus OsmosisBoth diffusion and osmosis are types of passive transport—cellular transport that does not require...
Potentiometry: Membrane Electrodes01:15

Potentiometry: Membrane Electrodes

Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at the...
Factors Affecting Erythropoiesis01:24

Factors Affecting Erythropoiesis

The cardiovascular system regulates the number of erythrocytes in the bloodstream to ensure optimal oxygen transport. It also prevents over-proliferation of these cells, which helps to maintain blood viscosity and flow rate.
Several factors influence the erythrocyte production rate, with tissue oxygen level being among the most critical. Intense exercise or high altitudes can cause tissue hypoxia, which triggers the kidneys to release more erythropoietin (EPO) into the bloodstream.
EPO then...