Glucose-6 phosphate dehydrogenase deficiency decreases the vascular response to angiotensin II.
BACKGROUND
Glucose-6-phosphate dehydrogenase (G6PD) regulates production of the reduced form of NADPH through the pentose phosphate pathway. G6PD may therefore affect superoxide anion production via vascular NADPH oxidase, which is key in mediating the vascular response to angiotensin II (Ang II). We determined the hypertensive and vascular hypertrophic response to Ang II in G6PD-deficient mice.


RESULTS
Ang II (0.7 mg/kg per day) was infused via subcutaneous osmotic pumps for 6 days in male hemizygote G6PD mutant (G6PD(mut)) and wild-type (WT) C3H mice. (1) Compared with WT, G6PD(mut) mouse aorta had 10% to 20% of G6PD activity and 50% less NADPH. (2) Basal systolic blood pressure was not significantly different in G6PD(mut) mice (WT 88+/-4 mm Hg versus G6PD(mut) 95+/-4 mm Hg), but Ang II increased blood pressure to a lower level in G6PD(mut) mice (WT 139+/-4 mm Hg versus G6PD(mut) 123+/-5 mm Hg; P<0.05). (3) Ang II increased aortic medial thickness less in G6PD(mut) mice (WT 71+/-2 mum versus G6PD(mut) 62+/-1 mum; P<0.01). (4) 3-o-Nitrotyrosine staining and dihydroethidium oxidation in the aorta was increased by Ang II less in G6PD(mut) mice. (5) Smooth muscle cells isolated from G6PD(mut) mice showed less Ang II-induced phosphorylation of Akt and p42/44 ERK.


CONCLUSIONS
G6PD deficiency may reduce vascular superoxide anion production by limiting production of the substrate for NADPH oxidase, thereby inhibiting oxidant-mediated Ang II-induced signaling pathways that contribute to hypertension and smooth muscle hypertrophy.
Matsui
Reiko
R
Vascular Biology Unit, Whitaker Cardiovascular Institute and Evans Department of Medicine, Boston University School of Medicine, Boston, Mass 02118-2393, USA. rmatsui@bu.edu
Xu
Shanqin
S
Maitland
Karlene A
KA
Hayes
Antoinette
A
Leopold
Jane A
JA
Handy
Diane E
DE
Loscalzo
Joseph
J
Cohen
Richard A
RA
D000804:Angiotensin II / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000473:pathology; D001808:Blood Vessels / Q000187:drug effects* / Q000503:physiopathology; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000503:physiopathology*; D006973:Hypertension / Q000209:etiology; D006984:Hypertrophy / Q000209:etiology; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism
D013481:Superoxides; D000804:Angiotensin II; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1