ASIC3: a lactic acid sensor for cardiac pain

Area of Science:

• Cardiology
• Neuroscience
• Pain Research

Background:

• Vasoocclusive pain, exemplified by angina, arises from inadequate blood supply to tissues, leading to ischemia.
• Conditions such as heart attack, sickle cell anemia, and peripheral artery disease involve vasoocclusive pain.
• Ischemia forces cells into anaerobic metabolism, releasing lactic acid.

Purpose of the Study:

• To investigate the role of specific ion channels in sensory neurons related to ischemia-induced pain.
• To understand the molecular mechanisms underlying the detection of lactic acid by cardiac sensory neurons.

Main Methods:

• Analysis of sensory neurons innervating the heart.
• Investigation of ion channel function in response to ischemic conditions and lactic acid.

Main Results:

• Sensory neurons in the heart are densely equipped with a specific ion channel.
• This ion channel is activated by lactic acid, a key mediator of ischemic pain.
• The channel is precisely tuned to detect the levels of lactic acid produced during muscle ischemia.

Conclusions:

• Lactic acid released during muscle ischemia acts as a direct stimulus for sensory neurons in the heart.
• This finding provides a novel molecular target for understanding and potentially treating vasoocclusive pain, including angina.