ISSN:
1365-2133
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
When epidermis from the uninvolved skin of psoriatic patients was incubated for 5 min in Hank's medium containing adrenaline and theophyllinc, the cychc AMP level consistently increased 20-30 times over the level observed when adrenaline was not added to the medium. On the other hand, when epidermis from the involved skin of psoriatic patients was incubated under the same experimental conditions, the cyclic AMP level increased only 2–5 times. Even when thcophylline, an inhibitor of specific cyclic AMP-phosphodiesterase, was omitted from the medium, a clearly demonstrable difference in sensitivity to adrenaline was evident in normal appearing and lesional psoriatic epidermis. These results indicate a faulty adenyl cyclase system in the involved epidermis of psoriatic lesions rather than a defective degradation process by the specific phosphodiesterase. Since the Km for adrenaline activation of adenyl cyclase was approximately the same in both the uninvolved and the involved epidermis and since the cyclic AMP increase by adrenaline was abolished by the addition of propranolol, the basic nature of the β-receptor (specifically the binding affinity to adrenaline) in the involved epidermis does not appear to be defective. On the other hand, the finding that the Value, for adrenaline activation is 10–20 times higher in the uninvoled than in the involved epidermis suggests that the poor response in the involved epidermis may be due to fewer available binding sites for adrenaline in the psoriatic lesion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2133.1975.tb03140.x
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