Effect of 1 alpha,25-dihydroxy vitamin D3 and vitamin E on insulin-induced glucose uptake in rat adipocytes.

Article Details

Citation

Huang Y, Ishizuka T, Miura A, Kajita K, Ishizawa M, Kimura M, Yamamoto Y, Kawai Y, Morita H, Uno Y, Yasuda K

Effect of 1 alpha,25-dihydroxy vitamin D3 and vitamin E on insulin-induced glucose uptake in rat adipocytes.

Diabetes Res Clin Pract. 2002 Mar;55(3):175-83.

PubMed ID
11850093 [ View in PubMed
]
Abstract

Vitamin E, an antioxidant, improves insulin sensitivity through the suppression of conventional PKC in vascular smooth muscle cells. It has been reported that vitamin E reduces platelet aggregation through the suppression of PKC alpha and beta (Diabetes 47 (1998) 1494). On the other hand, 1 alpha,25-dihydroxy vitamin D3 (1,25D3) activates conventional PKC and may subsequently cause insulin resistance. Against this background, we examined the effect of vitamin E and 1,25D3 on PKC beta and PKC zeta/lambda activities in vitro and 10 nM insulin-induced glucose uptake in rat adipocytes. In vitro PKC beta activity of adipocytes was slightly decreased by the addition of 1 microM vitamin E, but not PKC zeta/lambda activity. In contrast, a 10-1000 nM 1,25D3 dose responsively activated PKC beta activity of adipocytes (ED 50%, 10 nM), but not PKC zeta/lambda activity. Pretreatment with 1 microM vitamin E for 60 min did not improve the insulin-induced glucose uptake. On the other hand, pretreatment with a 10-1000 nM 1,25D3 dose responsively suppressed insulin-induced glucose uptake. Moreover, 1,25D3 increased membrane-associated PKC beta immunoreactivity for 60 min, but no additional increase in membrane-associated PKC beta immunoreactivity during treatment with insulin was observed. These results suggest that 1,25D3 reduces insulin-induced glucose uptake via activation of PKC beta, but not vitamin E in rat adipocytes.

DrugBank Data that Cites this Article

Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
alpha-Tocopherol succinateProtein kinase C alpha typeProteinHumans
Unknown
Not AvailableDetails
alpha-Tocopherol succinateProtein kinase C beta typeProteinHumans
Unknown
Not AvailableDetails
D-alpha-Tocopherol acetateProtein kinase C alpha typeProteinHumans
Unknown
Not AvailableDetails
D-alpha-Tocopherol acetateProtein kinase C beta typeProteinHumans
Unknown
Not AvailableDetails
Vitamin EProtein kinase C alpha typeProteinHumans
Unknown
Not AvailableDetails
Vitamin EProtein kinase C beta typeProteinHumans
Unknown
Not AvailableDetails