T. Michimata et al., NITRIC OXIDE-DEPENDENT SOLUBLE GUANYLATE-CYCLASE ACTIVITY IS DECREASED IN PLATELETS FROM MALE NIDDM PATIENTS, Life sciences, 59(17), 1996, pp. 1463-1471
Citations number
33
Categorie Soggetti
Biology,"Medicine, Research & Experimental","Pharmacology & Pharmacy
To elucidate the underlying mechanisms of platelet dysfunction in diab
etes mellitus, we examined the activity of soluble guanylate cyclase (
sGC), a key enzyme in the nitric oxide (NO)-related signalling pathway
, in platelets from NIDDM (non-insulin dependent diabetes mellitus) pa
tients. The sGC activity was determined by measuring the amount of cyc
lic GMP produced in platelet cytosol. In the first study, we investiga
ted the platelet sGC activity in untreated NIDDM patients without diab
etic complications. In the male NIDDM patients, sodium nitroprusside (
SNP) caused a significantly lower sGC response than that in age-matche
d control male subjects, while the enzyme activity of female diabetics
did not differ from that in the controls. Secondly, we investigated e
ffects of diabetic-associated factors on the enzyme activity in the ma
le NIDDM patients. There was no difference in the SNP-stimulated sGC a
ctivity in platelets from male diabetics between with and without reti
nopathy. In the male diabetic patients with retinopathy, however, the
platelet sGC activity was slightly increased by treatment with insulin
. Interestingly, the changes in enzyme activity did not correlate with
plasma glycosylated hemoglobin Ale levels in diabetic patients. The i
mpairment of the NO-related signalling pathway may contribute to the p
latelet dysfunction observed in patients with diabetes mellitus.