Endothelial cell dysfunction in mice after transgenic knockout of type 2, but not type 1, 11beta-hydroxysteroid dehydrogenase.
BACKGROUND
11beta-Hydroxysteroid dehydrogenase (11betaHSD) isozymes catalyze the interconversion of active and inactive glucocorticoids, allowing local regulation of corticosteroid receptor activation. Both are present in the vessel wall; here, using mice with selective inactivation of 11betaHSD isozymes, we test the hypothesis that 11betaHSDs influence vascular function.


RESULTS
Thoracic aortas were obtained from weight-matched male wild-type (MF1x129 cross(+/+)), 11betaHSD1(-/-), and 11betaHSD2(-/-) mice. mRNA for both isozymes was detected in wild-type aortas by RT-PCR. 11betaHSD activity in aortic homogenates (48.81+/-4.65% conversion) was reduced in both 11betaHSD1(-/-) (6.36+/-2.47% conversion; P<0.0002) and 11betaHSD2(-/-) (24.71+/-3.69; P=0.002) mice. Functional responses were unaffected in aortic rings isolated from 11betaHSD1(-/-) mice. In contrast, aortas from 11betaHSD2(-/-) mice demonstrated selectively enhanced constriction to norepinephrine (E(max) 4.28+/-0.56 versus 1.72+/-0.47 mN/mm; P=0.004) attributable to impaired endothelium-derived nitric oxide activity. Relaxation responses to endothelium-dependent and -independent vasodilators were also impaired. To control for chronic renal mineralocorticoid excess, MF1 mice were treated with fludrocortisone (16 weeks) but did not reproduce the functional changes observed in 11betaHSD2(-/-) mice.


CONCLUSIONS
Although both 11betaHSD isozymes are present in the vascular wall, reactivation of glucocorticoids by 11betaHSD1 does not influence aortic function. Mice with 11betaHSD2 knockout, however, have endothelial dysfunction causing enhanced norepinephrine-mediated contraction. This appears to be independent of renal sodium retention and may contribute to hypertension in 11betaHSD2 deficiency.
Hadoke
P W
PW
Endocrinology, Endothelial Cell Biology, and Molecular Physiology groups, University of Edinburgh, Edinburgh, UK. phadoke@srv0.med.ed.ac.uk
Christy
C
C
Kotelevtsev
Y V
YV
Williams
B C
BC
Kenyon
C J
CJ
Seckl
J R
JR
Mullins
J J
JJ
Walker
B R
BR
D042842:11-beta-Hydroxysteroid Dehydrogenases; D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000201:enzymology / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D005438:Fludrocortisone / Q000494:pharmacology; D006913:Hydroxysteroid Dehydrogenases / Q000172:deficiency* / Q000235:genetics; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000172:deficiency / Q000235:genetics; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D008901:Mineralocorticoids / Q000494:pharmacology; D008981:Molsidomine / Q000031:analogs & derivatives* / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012701:Serotonin / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology; D015430:Weight Gain / Q000187:drug effects
D007527:Isoenzymes; D008901:Mineralocorticoids; D012333:RNA, Messenger; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D012701:Serotonin; C002385:linsidomine; D011189:Potassium Chloride; D008981:Molsidomine; D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases; D000109:Acetylcholine; D005438:Fludrocortisone; D009638:Norepinephrine