Abstract
To evaluate responses of the autonomic nervous system (ANS) in rats, we tried to develop some simple non-invasive tests like as clinically used for patients.
Under Nembutal anesthesia, skin blood flows (SBFs) were measured bilaterally in the plantar surface of the rat hind paw by laser Doppler flowmetry. Simultaneously, ECG, a respiration and the rectal temperature were also monitored. These experiments were carried out under the constant environment (room temperature: 23°C, humidity: 59%). Following stimuli were applied: i) somatic noxious stimuli (pricking of the cornea, pinching of the tail and mechanical pressure to the gastrocnemius muscle), ii) cooling of the tail with ethyl chloride, iii) ANS function tests clinically utilized in human (Valsalva-like maneuver, Aschner reflex, and head-up and -down tilt). In addition, the influence of body temperature (BT) to ANS functions was examined at different BTs by cooling or heating the animal body. Power spectral analysis of variabilities of SBFs and heart rate, and cross-spectral analysis between them showed the details of the changes of ANS functions. In some experiments, β-adrenergic and muscarinic blockers were applied to assess the degree of the involvement of the sympathetic and parasympathetic nervous system.
It is suggested that these non-invasive tests in rats are available as simple and reliable ANS function tests. These tests may be useful for animal models with pathological condition such as one with chronic pain.
[Jpn J Physiol 54 Suppl:S201 (2004)]
