TY - JOUR
T1 - Reduced vascular responses to soluble guanylyl cyclase but increased sensitivity to sildenafil in female rats with type 2 diabetes
AU - Goulopoulou, Styliani
AU - Hannan, Johanna L.
AU - Matsumoto, Takayuki
AU - Ogbi, Safia
AU - Ergul, Adviye
AU - Webb, R. Clinton
N1 - Publisher Copyright:
© 2015 the American Physiological Society.
PY - 2015/7/15
Y1 - 2015/7/15
N2 - Impaired nitric oxide (NO), soluble guanylyl cyclase (sGC), and cyclic guanosine monophosphate (cGMP) signaling (NO-sGC-cGMP) has been implicated in the pathogenesis of diabetic vascular dysfunction. Efforts to directly target this signaling have led to the development of sGC agonists that activate the heme group of sGC (stimulators) or preferentially activate sGC when the heme is oxidized (activators). In this study, we hypothesized that resistance arteries from female rats with spontaneous type 2 diabetes (Goto-Kakizaki rats, GK) would have reduced vasodilatory responses to heme-dependent sGC activation and increased responses to heme-independent sGC activation compared with control rats (Wistar). Endothelium-dependent and -independent relaxation was assessed in isolated segments from mesenteric resistance arteries (MA) mounted in a wire myograph. GK MA had reduced responses to acetylcholine (pEC50: 7.96 ± 0.06 vs. 7.66 ± 0.05, P< 0.05) and sodium nitroprusside (pEC50: 8.34 ± 0.05 vs. 7.77 ± 0.04, P < 0.05). There were no group differences in 8-bromoguanosine cGMP-induced relaxation and protein kinase G1 expression (P > 0.05). GK MA had attenuated responses to BAY 41–2272 (heme-dependent sGC stimulator; pEC50: 7.56 ± 0.05 vs. 6.93± 0.06, P < 0.05) and BAY 58–2667 (hemeindependent sGC activator; pEC50: 10.82 ± 0.07 vs. 10.27 ± 0.08, P < 0.05) and increased sensitivity to sildenafil [phosphodiesterase 5 (PDE5) inhibitor; pEC50: 7.89 ± 0.14 vs. 8.25 ± 0.13, P < 0.05]. Isolated resistance arteries from female rats of reproductive age that spontaneously develop type 2 diabetes have increased sensitivity to PDE5 inhibition and reduced responsiveness to sGC activators and stimulators.
AB - Impaired nitric oxide (NO), soluble guanylyl cyclase (sGC), and cyclic guanosine monophosphate (cGMP) signaling (NO-sGC-cGMP) has been implicated in the pathogenesis of diabetic vascular dysfunction. Efforts to directly target this signaling have led to the development of sGC agonists that activate the heme group of sGC (stimulators) or preferentially activate sGC when the heme is oxidized (activators). In this study, we hypothesized that resistance arteries from female rats with spontaneous type 2 diabetes (Goto-Kakizaki rats, GK) would have reduced vasodilatory responses to heme-dependent sGC activation and increased responses to heme-independent sGC activation compared with control rats (Wistar). Endothelium-dependent and -independent relaxation was assessed in isolated segments from mesenteric resistance arteries (MA) mounted in a wire myograph. GK MA had reduced responses to acetylcholine (pEC50: 7.96 ± 0.06 vs. 7.66 ± 0.05, P< 0.05) and sodium nitroprusside (pEC50: 8.34 ± 0.05 vs. 7.77 ± 0.04, P < 0.05). There were no group differences in 8-bromoguanosine cGMP-induced relaxation and protein kinase G1 expression (P > 0.05). GK MA had attenuated responses to BAY 41–2272 (heme-dependent sGC stimulator; pEC50: 7.56 ± 0.05 vs. 6.93± 0.06, P < 0.05) and BAY 58–2667 (hemeindependent sGC activator; pEC50: 10.82 ± 0.07 vs. 10.27 ± 0.08, P < 0.05) and increased sensitivity to sildenafil [phosphodiesterase 5 (PDE5) inhibitor; pEC50: 7.89 ± 0.14 vs. 8.25 ± 0.13, P < 0.05]. Isolated resistance arteries from female rats of reproductive age that spontaneously develop type 2 diabetes have increased sensitivity to PDE5 inhibition and reduced responsiveness to sGC activators and stimulators.
KW - Sildenafil
KW - Soluble guanylyl cycle agonists
KW - Type 2 diabetes
KW - Vascular smooth muscle
KW - Vasorelaxation
UR - http://www.scopus.com/inward/record.url?scp=84937417518&partnerID=8YFLogxK
U2 - 10.1152/ajpheart.00079.2015
DO - 10.1152/ajpheart.00079.2015
M3 - Article
C2 - 25957216
AN - SCOPUS:84937417518
SN - 0363-6135
VL - 309
SP - H297-H304
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 2
ER -