Desensitization of A1 Adenosine Receptors
It is well known that exposure of sensitive cells to receptor agonists can cause a progressive reduction in their capacity to respond to this and related agonists. This phenomenon has been observed with cells expressing receptors from different superfamilies, and has been termed desensitization, refractoriness,tolerance, or tachyphylaxis . The mechanisms responsible for this phenomenon have been studied extensively in cells that synthesize cyclic AMP in response to beta-adrenergic agonists. Exposure of such cells to isoproterenol or similar drugs may result in receptor uncoupling, receptor sequestration, and ultimately, in downregulation of receptors, resulting in a decline in the actual number of receptors .
KeywordsAdenosine Histamine Caffeine Catecholamine Sine
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