[The effects of two and five percent aqueous phenol on the cat tibial nerve in situ--II: Effect on the circulation of the tibial nerve].

The previous report of ours showed that the biphasic depression of the compound action potentials in cat tibial nerve was observed after administration of 2% aqueous phenol, and the delayed depression was considered to be the result of the ischemia of the nerve fibers caused by the vascular damage with phenol. This second report includes two studies; one is the change in total blood flow of the cat tibial nerve, and the other is the observation of the microcirculatory damage of the nerve surface and its contribution to the block of nerve transmission. The sacral and tibial nerves were exposed under microscopic vision and platinum electrodes were placed on both nerves; one for nerve stimulation and the other for recording its action potential. First, total blood flow of the tibial nerve tissue was measured using laser doppler flow meter ALF-2100 with A-type probe (Advance), and secondly, using videomicroscope VMS-1300 with object lens LL-006W (Nihon Kohden), magnifying objects 500 times, the change of the microcirculation of the nerve was observed. With the doppler flow meter, no statistical changes in total blood flow was recognized with both 2% and 5% aqueous phenol. The examination of microcirculation was followed. In cases of physiologic saline injection, the blood flow stagnated within one minute after injection. After recovery, no more change was recognized in microcirculatory blood flow. In cases of 2% aqueous phenol, prior to the delayed depression of the compound action potentials, the progressive damage in microcirculation, such as slugging, oscillation, plasma skimming and inverted flow, were observed after transient cessation of the microcirculation.(ABSTRACT TRUNCATED AT 250 WORDS)