The Effect of Alternating Current Iontophoresis on Rats with the Chronic Constriction Injury to the Infraorbital Nerve

This study aimed to examine the effect of AC iontophoresis on rats with the chronic constriction injury (CCI) to the infraorbital nerve by animal experiments. CCI model rats were divided into four groups, namely, rats that received general anesthesia for 60 min except AC IOP (CCI: n = 5), AC IOP with 0.9% physiological saline for 60 min (CCI + saline AC IOP: n = 5), AC IOP with 4% lidocaine hydrochloride for 60 min (CCI + lidocaine AC IOP: n = 5), and attachment of two electrodes soaked with 4% lidocaine hydrochloride to the facial skin for 60 min (CCI + attach lidocaine: n = 5). In the CCI + lidocaine AC IOP group, an elevated withdrawal threshold was observed after AC IOP, and the duration of efficacy was longer compared with that in the CCI + saline AC IOP and CCI + attached lidocaine groups. A significant decrease in the number of Fos-like immunoreactive (LI) cells was observed in the CCI + lidocaine AC IOP group compared with that in the CCI group. These findings suggest that the effect of CCI + lidocaine AC IOP group may be caused by active permeation of lidocaine into the facial skin and electrical stimulation of the trigeminal nucleus

EFFECTS OF ACUPUNCTURE ANESTHESIA ON THE PITUITARY GLAND

The skin pain threshold was elevated significantly by weak and nonstressful acupuncture stimulation. Although an analgesic effect was obtained by acupuncture stimulation, the β-E, ACTH, GH and TSH levels were not changed. These findings indicate that these hormone levels were not necessarily related to the skin pain threshold elevation. It is concluded therefore that an analgesic effect was induced without involving the pituitary gland by the weak acupuncture stimulation employed in our study. However, the magnitude of the stimulation may determine whether or not an analgesic effect is mediated by the pituitary gland. The possibility remains that strong acupuncture stimulation produces stress-induced analgesia (SIA). Further detailed research should be attempted

RELATIONSHIP BETWEEN SUBJECTIVE PAIN ESTIMATION AND SOMATOSENSORY EVOKED POTENTIALS BY ELECTRICAL TOOTH STIMULATION

The relationship between the amplitude of somatosensory evoked potentials (SEP) and the subjective pain estimation using a visual analogue scale (VAS) was exmained in 8 volunteers undergoing randomized electrical tooth stimulation with 3 different intensities. Randomized stimulation was used instead of repetitive stimulation with a fixed intensity in order to minimize the phenomena of habituation and expectancy in recording the SEP and VAS. The VAS scores increased significantly with the stimulus intensity. The amplitude with a latency between 160 and 300 msec (N 160-P300) showed a significant increase with the increased intensity. But the amplitudes between 60 and 110 msec (N60-P 110) and between 110 and 160 msec (P110-N 160) showed no significant change. There was a significant correlation between the amplitude of N 160-P300 and the VAS scores.These findings indicate that the component between 160 and 300 msec reflects the perceived pain intensity and the psychological evaluation processes such as cognition, meaning, interpretation and appreciation of pain. The method of randomized stimulation can serve as a simple and useful way for the objective or subjective pain estimation

EFFECT OF THIAMYLAL AND DIAZEPAM ON RELEASE OF MYOGLOBIN AND CREATINE PHOSPHOKINASE BY SUCCINYLCHOLINE CHLORIDE DURING HALOTHANE ANESTHESIA

The effects of thiamylal and diazepam on the release of myoglobin and creatine phosphokinase following the administration of succinylcholine chloride during halothane anesthesia were studied. Thirty patients receiving halothane anesthesia were divided into three groups. In Group I, 1.5-2 mg/kg of thiamylal were given intravenously as pretreatment before the injection of succinylcholine chloride. In Group II, 0.3 mg/kg of diazepam were given and, in Group III, only succinylcholine chloride was injected.A significant increase in the serum myoglobin and creatine phosphokinase levels was observed in all groups. However, the values in Group I were significantly lower than those in Groups II and III and a significant difference was not detected between Group II and Ill. Our results indicate that thiamylal has a considerable inhibitory effect on the release of myoglobin and creatine phosphokinase from the muscle following the administration of succinylcholine chloride