A. Enz, P. Iwangoff, A. Chappuis
1978
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0
Influential Citations
8
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Quality indicators
Journal
Gerontology
Abstract
Dihydroergotoxine mesylate (DHET; active substance of Hydergine) was shown to be a stronger inhibitor of the low-Km than of the high-Km phosphodiestrase (PE) in cat and rat brain homogenates. The inhibition due to DHET was greater when a purified low-Km PE preparation originating from a sonicated pellet (100,000 g) of rat brain tissue was used. The drug alters the kinetic properties of the enzyme, producing a lowering of the negative cooperativity effect. This kind of PE inhibition is of particular importance at normal cellular cAMP levels, but does not interfere with cAMP production by hormonal stimulation.