Bionic baroreceptor corrects postural hypotension in rats with impaired baroreceptor

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Neuroscience

Background:

• Impaired arterial baroreflex function leads to orthostatic hypotension, particularly in the elderly due to age-related sensitivity decline.
• Current treatments for orthostatic hypotension are limited, highlighting the need for novel therapeutic approaches.
• Age-associated degradation of baroreceptor sensitivity is a key factor in orthostatic hypotension.

Purpose of the Study:

• To develop a novel bionic baroreceptor (BBR) system.
• To evaluate the efficacy of the BBR in correcting experimentally induced postural hypotension.
• To investigate the potential of BBR as a treatment for orthostatic hypotension.

Main Methods:

• Developed a BBR comprising a pressure sensor, regulator, and neurostimulator.
• Utilized Sprague-Dawley rats with isolated baroreceptor regions and aortic depressor nerve stimulation.
• Employed a white noise technique to determine the baroreceptor encoding rule for BBR regulation.
• Compared BBR function to native baroreflex and absence of baroreflex during tilt-induced hypotension.

Main Results:

• The BBR successfully reproduced native baroreflex function by matching intracarotid sinus pressure to pulsatile aortic pressure.
• The BBR corrected tilt-induced hypotension comparably to the native baroreflex (-41±5 mm Hg vs. -39±5 mm Hg).
• Arterial pressure was significantly better maintained with the BBR compared to the absence of baroreflex (-41±5 mm Hg vs. -63±5 mm Hg).

Conclusions:

• The developed bionic baroreceptor effectively restores arterial pressure buffering function.
• The study demonstrates the feasibility of using a BBR to counteract hypotension.
• Further research in larger animal models and humans is required to assess long-term effects and safety.