Perivascular innervation is lost in experimental atherosclerosis

Area of Science:

• Vascular Biology
• Neuroscience
• Cardiovascular Research

Background:

• Perivascular nerve networks regulate vascular function.
• Cholesterol-rich diets and mechanical stress can impact arterial health.
• The relationship between intimal thickening and nerve integrity is not well understood.

Purpose of the Study:

• To investigate the impact of a cholesterol-rich diet and carotid artery manipulation on the perivascular nerve network.
• To determine if intimal thickening is associated with changes in nerve fiber presence and integrity.

Main Methods:

• New Zealand White rabbits were fed a high-cholesterol diet and subjected to silastic collar placement around the carotid artery for 14 days.
• Immunohistochemistry was used to identify nerve fibers (neuropeptide Y, tyrosine hydroxylase, calcitonin gene-related peptide, substance P).
• Transmission electron microscopy examined nerve fiber location and degeneration.

Main Results:

• Focal intimal thickening occurred in 10/12 rabbits with the collar and high-cholesterol diet.
• Intimal thickening was associated with the disappearance of the perivascular nerve network.
• Sham-operated arteries and non-responsive arteries showed intact nerve networks.
• Nerve fiber degeneration was observed in areas of intimal thickening and proliferation.

Conclusions:

• This study demonstrates a novel association between carotid artery intimal thickening and perivascular nerve network degeneration.
• The findings suggest a potential role for nerve damage in the development of arterial wall changes.
• Further research is needed to elucidate the cause and functional implications of this nerve degeneration.