Aging does not affect soluble guanylate cyclase redox state in mouse aortas

Area of Science:

• Cardiovascular Biology
• Aging Research
• Oxidative Stress

Background:

• Aging is linked to endothelial dysfunction and reduced nitric oxide (NO) bioavailability.
• Reactive oxygen species (ROS) increase with age, potentially affecting NO signaling pathways.
• The impact of aging on the redox state of soluble guanylate cyclase (sGC) in blood vessels is not well understood.

Purpose of the Study:

• To investigate whether aging affects the redox equilibrium of vascular sGC.
• To determine if systemic oxidative stress in aged mice impacts vascular sGC function.

Main Methods:

• Comparison of aged (19-20 months) and young (2-3 months) mice.
• Measurement of plasma thiobarbituric acid-reactive substances (TBARS) and aortic superoxide levels.
• Assessment of relaxant responses and cyclic guanosine monophosphate (cGMP) production in endothelium-denuded aortas using sGC stimulator (BAY 41-2272) and activator (BAY 60-2770).

Main Results:

• Aged mice showed higher plasma TBARS but similar aortic superoxide levels compared to young mice.
• Vascular responses to sGC modulators (BAY 41-2272 and BAY 60-2770) and cGMP production were comparable between aged and young mice.
• These results indicate no significant difference in vascular sGC redox equilibrium between aged and young mice.

Conclusions:

• Aging, despite increased systemic oxidative stress, does not alter vascular smooth muscle ROS generation or sGC redox equilibrium.
• Vascular sGC redox equilibrium appears to be maintained unless ROS levels are elevated within the vascular smooth muscle itself.