Rat brain membrane-bound delta opioid receptor: Loss and reactivation of binding on dialysis and aging at low temperature

Abstract

<span style="font-size:14.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">A change in the environment of rat brain membranes by dialysis from phosphate buffered saline (PBS) to 10 m<i style="mso-bidi-font-style:normal">M</i> potassium phosphate (<i style="mso-bidi-font-style:normal">p</i>H 7.2) led to a 35% loss in delta opioid receptor binding. while alteration of membrane structure on freezing at -20°C for 55 days led to 85% loss of receptor binding. The dialysate. 200 m<i style="mso-bidi-font-style:normal">M</i> KCI and NaCI restored receptor binding lost on dialysis. This K⁺ and Na⁺ restabilisation of the receptor can be through cation-<span style="font-size:14.0pt; font-family:" arial="" unicode="" ms";mso-fareast-font-family:"times="" new="" roman";="" mso-bidi-font-family:"times="" roman";mso-ansi-language:en-in;mso-fareast-language:="" en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">π<span style="font-size:14.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:ar-sa"="" lang="EN-IN"> bonding. interactions that are Suited the lipid bilayer. In membranes stored at -20°C, the loss or binding is attributed to increased membrane fluidity by phospholipase A₂ action on membrane phospholipids. resulting in an increase of free fatty acids. K⁺ but not Na⁺ restabilization of these membrane receptors may be due to the ability or K⁺ 10 decrease membrane fluidity.</span></span></span>