Poikilothermic organisms are exposed to frequent changes in environmental conditions and their survival depends on their ability to acclimate to such changes. Changes in ambient temperature and osmolarity cause fluctuations in the fluidity of cell membranes. Such fluctuations are considered to be critical to the initiation of the regulatory reactions that ultimately lead to acclimation. The mec...

Suspended planar lipid membranes (or black lipid membranes (BLMs)) are widely used for studying reconstituted ion channels, although they lack the chemical and mechanical stability needed for incorporation into high-throughput biosensors and biochips. Lipid polymerization enhances BLM stability but is incompatible with ion channel function when membrane fluidity is required. Here, we demonstrat...

In the present study, to determine a possible role of insulin in the regulation of membrane functions, we have examined the effects of insulin on the membrane fluidity of erythrocytes in patients with essential hypertension and normotensive subjects. Membrane fluidity of erythrocytes obtained from hypertensive and normotensive subjects were evaluated by means of an electron paramagnetic resonan...

Several barrier epithelia such as renal collecting duct, urinary bladder, and gastric mucosa maintain high osmotic pH and solute gradients between body compartments and the blood by means of apical membranes of exceptionally low permeabilities. Although the mechanisms underlying these low permeabilities have been only poorly defined, low fluidity of the apical membrane has been postulated. The ...

The role of membrane fluidity in determining red blood cell (RBC) deformability has been suggested by a number of studies. The present investigation evaluated alterations of RBC membrane fluidity, deformability and stability in the presence of four linear alcohols (methanol, ethanol, propanol and butanol) using ektacytometry and electron paramagnetic resonance (EPR) spectroscopy. All alcohols h...

Membrane fluidity in human erythrocytes was measured by a spin label method using an electron spin resonance spectrometer in healthy volunteers after ingestion of alcohol (1.5 ml of whisky/kg body weight). Fluidity in the lipid bilayer closer to the hydrophilic face decreased at 30 min and 90 min, and fluidity in the hydrophobic core decreased at 90 min after ingestion of alcohol. In the same e...

Relationships between the thermo-sensitive response and membrane lipid fluidity were studied using a ciliated protozoan, Paramecium multimicronucleatum. Paramecium elicits a transient membrane depolarization in response to a cooling stimulus (temperature drop). The depolarization amplitude was largest when the cooling stimulus was started from the culture temperature, whilst when cooling starte...

1. Human erythrocyte membrane cholesterol, fluidity and basal and calmodulin-stimulated calcium pump (Ca(2+)-Mg(2+)-ATPase) activities were compared in 24 patients with primary combined hyperlipidaemia and 20 age-matched normolipidaemic control subjects. 2. There was no correlation between serum and membrane cholesterol. Despite the differences in serum cholesterol levels between the two groups...

BACKGROUND The field of structural dynamics of cytoskeletons in living cells is gathering wide interest, since better understanding of cytoskeleton intracellular organization will provide us with not only insights into basic cell biology but may also enable development of new strategies in regenerative medicine and cancer therapy, fields in which cytoskeleton-dependent dynamics play a pivotal r...

The effects of various insecticides on the fluidity of mitochondrial membranes and cross-resistance were investigated in the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae) using strains that were both resistant and susceptible to avermectin. The resistant strain of P. xylostella, AV-R, developed 1078-fold resistance to avermetins with a high level of cross-resistance to t...