Measurement of COX-2 expression level in mesenteric resistance arteries isolated from young and old LZ and ZDF rats using immunolabelling (A) and Western-blot analysis (B).

<p>Mean ± SEM is presented (n = 10 per group). #P<0.01, ZDF versus LZ. *P<0.01, old versus young rats.</p

Rat body weight, glycaemia and mean arterial blood pressure (MAP) were measured in 3- and 12-month old LZ and ZDF rats.

<p>Mean±SEM is presented (n = 12 rats per group).</p>*<p>P<0.05, ZDF versus LZ of the same age.</p>#<p>P<0.05, effect of age within each group.</p

Measurement of the reactive oxygen species level in mesenteric resistance arteries isolated from LZ and ZDF rats using dihydroethydin microfluorography (A).

<p>The expression level of the NADP(H)-oxidase subunits gp91 and p67 (B) was measured using Western-Blot analysis. Mean ± SEM is presented (n = 10 per group). #P<0.01, ZDF versus LZ. *P<0.01, old versus young rats.</p

Effect of the acute treatment of mesenteric resistance arteries with the antioxydant tempol on acetylcholine-induced relaxation in mesenteric resistance arteries isolated from young (A) and old (B) LZ and ZDF rats.

<p>Mean ± SEM is presented (n = 10 per group). #P<0.01, ZDF versus LZ. *P<0.01, old versus young rats. &P<0.05, effect of tempol on acetylcholine-induced relaxation.</p

Acetylcholine-induced relaxation in young (A) and old (B) LZ and ZDF rats.

<p>Relaxation was obtained before and after NO synthesis inhibition with the NO synthesis blocker L-NAME. The inserts show the precontraction applied before adding acetylcholine. Beta-actin and eNOS expression levels were measured using Western-Blot analysis (typical blots on the right side). Data is given as a ratio eNOS/beta-actin (<b>C</b>). Mean ± SEM is presented (n = 10 per group). #P<0.01, ZDF versus LZ. *P<0.01, old versus young rats.</p

Effect of an acute treatment of mesenteric resistance arteries with the COX-2 inhibitor NS398 or NS398 and the antioxidant tempol on acetylcholine-induced relaxation in young (A) and old (B) LZ and ZDF rats.

<p>Mean ± SEM is presented (n = 10 per group). ^#P<0.01, ZDF versus LZ. *P<0.01, old versus young rats. ^&P<0.05, effect of NS398 alone on acetylcholine-induced relaxation. ^$P<0.05, effect of NS398+tempol on acetylcholine-induced relaxation.</p

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<p>Aim/hypothesis:In utero exposure to maternal diabetes increases the risk of developing hypertension and cardiovascular disorders during adulthood. We have previously shown that this is associated with changes in vascular tone in favor of a vasoconstrictor profile, which is involved in the development of hypertension. This excessive constrictor tone has also a strong impact on vascular structure. Our objective was to study the impact of in utero exposure to maternal diabetes on vascular structure and remodeling induced by chronic changes in hemodynamic parameters.</p><p>Methods and Results: We used an animal model of rats exposed in utero to maternal hyperglycemia (DMO), which developed hypertension at 6 months of age. At a pre-hypertensive stage (3 months of age), we observed deep structural modifications of the vascular wall without any hemodynamic perturbations. Indeed, in basal conditions, resistance arteries of DMO rats are smaller than those of control mother offspring (CMO) rats; in addition, large arteries like thoracic aorta of DMO rats have an increase of smooth muscle cell attachments to elastic lamellae. In an isolated perfused kidney, we also observed a leftward shift of the flow/pressure relationship, suggesting a rise in renal peripheral vascular resistance in DMO compared to CMO rats. In this context, we studied vascular remodeling in response to reduced blood flow by in vivo mesenteric arteries ligation. In DMO rats, inward remodeling induced by a chronic reduction in blood flow (1 or 3 weeks after ligation) did not occur by contrast to CMO rats in which arterial diameter decreased from 428 ± 17 μm to 331 ± 20 μm (at 125 mmHg, p = 0.001). In these animals, the transglutaminase 2 (TG2) pathway, essential for inward remodeling development in case of flow perturbations, was not activated in low-flow (LF) mesenteric arteries. Finally, in old hypertensive DMO rats (18 months of age), we were not able to detect a pressure-induced remodeling in thoracic aorta.</p><p>Conclusions: Our results demonstrate for the first time that in utero exposure to maternal diabetes induces deep changes in the vascular structure. Indeed, the early narrowing of the microvasculature and the structural modifications of conductance arteries could be a pre-emptive adaptation to fetal programming of hypertension.</p

Vascular relaxation of mesenteric arteries in control (CMO) and diabetic (DMO) mother offspring.

<p>Concentration-response curve to acetylcholine (ACh, A) and sodium nitroprusside (SNP, B). Bar graphs represent the level of pre-contraction induced by 10^-6M phenylephrine. Values are mean ± SEM (n = 7 minimum per group). * p<0.05 and ** p<0.01 DMO vs. CMO.</p

Western blot analysis of contractile proteins.

<p>(A) Activity of MLC reflected by the pMLC/MLC ratio; (B) activity of PKA reflected by the pPKA/PKA ratio; (C) activity of RhoA reflected by the RhoA-GTP/RhoA ratio; (D) activity of MAP kinase P38 reflected by the ratio of pP38/P38 and protein expression levels of (E) filamin-1 and (F) profilin-1, normalised to β-actin were measured in mesenteric arteries from 3- and 18-month old CMO and DMO. Values are mean ± SEM (n = 5 minimum per group). * p<0.05 and ** p<0.01 DMO vs. CMO at the same age, ## p<0.05 18 vs. 3 months of age.</p

Prostacyclin-mediated relaxation and receptor expression level in control (CMO) and diabetic (DMO) mother offspring.

<p>(A) Relative protein expression of the prostacyclin receptor (IP receptor) was analysed by Western-blot in mesenteric arteries of CMO (open bars, n = 5) and DMO (solid bars, n = 5); each value was normalised to β-actin protein expression. (B) Left panel represents phenylephrine (PE)-induced pre-contraction level; right panel shows concentration-relaxation response curve to beraprost of mesenteric arteries in CMO and DMO (n = 5 at 3 months and n = 7 at 18 months of age for each group). Values are mean ± SEM. (C) Measurement of serum 6-keto-PGF1-α (prostacyclin metabolite) in CMO (n = 6) and DMO (n = 6). Each bar graph represents mean ± SEM. * p<0.05 DMO vs. CMO and ## p<0.01 18 vs. 3 months-old animals.</p