(1) CO can induce an chemical modification of histidine residue of KCa channels, changing their open probabiliy. See our paper on J.B.C. 272: 8222, 1997.
(2) Increased HO-1 expression in diabetes has been shown in STZ-induced diabetic rats (Diabetes 47:1318, 1998). Diminished HO-1 expression was found in diabetic in retinal pigment epithelium cells (Curr Eye Res. 16: 380,1997). It looks like that HO-1 change in diabetes is a general phenomenon but has tissue-specific patterns.