RESUMEN
Studies on the platelet alpha-adrenoceptor subtypes were carried out in 19 subjects with treated diabetes mellitus and 15 normal age and sex-matched controls. By utilising selective antagonists, it was noted that all the normal human platelets exhibited the alpha-2 adrenoceptor. 7 diabetics (37%) expressed both the alpha-1 and alpha-2 adrenoceptors and diabetic complications along with hypertension were most common in this group. Another 7 diabetics (37%) expressed the alpha-2 receptor only and diabetic complications were minimum in this group. Interestingly, 5 diabetics (26%) did not express either the alpha-1 or alpha-2 receptor and these patients occupied an intermediate position with regard to diabetic complications. Thus, it was concluded that platelet alpha-1 adrenoceptors perhaps indicated a poor prognosis in diabetes mellitus, opening up future scope for work in this area.