Autonomic Nervous System (Ans) Dysfunction Exacerbates Inflammation In Dextran Sulfate (Dss) Model Of Ulcerative Colitis.

The autonomic nervous system (ANS) plays an important role in modulating ones response to stress.We have previously demonstrated in the stress reactivation model of colitis that pretreatment with hexamethonium, a nicotinic ganglionic blocking agent, prevents stress-induced reactivation colitis.In this study we assessed neurocardiac response to stress.Biopotential transmitters were surgically implanted subcutaneously, for later recording of ECG' s in conscious rats.Once rats had recovered (~l week), intrarectal (ir) dinitrobenzene sulfonic acid (DNB), 20 mg dissolved in 250 J.Ll 40% ethanol was administered.Six weeks later rats were subjected to 3hr restraint stress (RS).Twenty-min ECG recordings were taken at 5 min, 2hr into the stress and 30 min post stress.Heart rate variability as measured from the ECG's was subjected to power spectral analysis and low frequency (LF.predominantly sympathetic) and high frequency (HF, predominantly parasympathetic) spectrums determined.One hr post stress rats