Sarin produces delayed cardiac and central autonomic changes.

Area of Science:

• Neuroscience
• Cardiovascular Physiology
• Toxicology

Background:

• Acetylcholinesterase (AChE) inhibitors, like sarin, are neurotoxic agents.
• Understanding their cardiovascular effects, especially at low doses, is crucial.

Purpose of the Study:

• To evaluate acute and delayed effects of low-dose sarin on cardiac autonomic and brainstem catecholaminergic function in mice.
• To investigate sarin's impact on cardiovascular autonomic modulation.

Main Methods:

• Telemetric arterial catheters in mice for blood pressure (BP) and pulse interval (PI) variability measurement.
• Autoregressive spectral analysis for PI oscillations and in situ hybridization (ISH) for tyrosine hydroxylase (TH) mRNA expression in brainstem.
• Sarin exposure (8 microg/kg) with measurements at 1 and 10 weeks.

Main Results:

• Sarin did not affect blood AChE activity, heart rate (HR), or BP.
• A biphasic PI variance response: early increase (+140%) and delayed decrease (-62%) at >2 months.
• Increased TH mRNA in locus coeruleus and dorsal vagal complex.

Conclusions:

• Low-dose sarin induces delayed impairment in heart rate variability, suggesting adverse cardiovascular effects.
• Sarin's effects on autonomic modulation challenge the use of AChE inhibitors for cardiovascular risk.