Muscarinic cholinergic binding sites on rat lymphocytes.
Costa-LG; Kaylor-G; Murphy-SD
Immunopharmacology 1988 Nov-Dec; 16(3):139-149
A more comprehensive pharmacological characterization was sought of muscarinic cholinergic binding sites in rat lymphocytes. Male Sprague-Dawley-rats were used for the isolation of spleen lymphocytes on a histopaque gradient. The lymphocytes were then incubated in Hank's buffer with tritium labeled quinuclidinyl- benzilate (3H-QNB). The binding of 3H-QNB was linear with increasing protein concentrations and was saturable. Several cholinergic muscarinic drugs were able to inhibit 3H-QNB, as determined through an extensive pharmacological analysis of the binding sites. Muscarinic antagonists were more potent than agonists. Lipophilic drugs were more potent than hydrophilic drugs. 3H-QNB binding was also inhibited by several noncholinergic drugs. These drugs behaved similarly in rat brain membranes, while a third group of noncholinergic drugs and neurotransmitters remained inactive. Circulating lymphocytes and lymphocyte membranes from rats gave the same results. The authors suggest that lymphocytes possess muscarinic receptors which share several, but not all, of the characteristics of the same receptors in brain and other tissues. The status of the muscarinic receptors in solid tissues can be monitored by measuring these binding sites.
NIOSH-Publication; NIOSH-Grant; Grants-other; Laboratory-animals; Blood-cells; Drug-interaction; Neurotransmitters; Cholinergic-receptors; In-vitro-studies
Environmental Health University of Washington Dept of Environ Hlth, SC-34 Seattle, WA 98195
Other Occupational Concerns; Grants-other
University of Washington, Seattle, Washington