THE EFFECTS OF CATECHOLAMINES ON HEMORRHAGIC SHOCK IN DOGS

The effects of isoproterenol, dopamine, dobutamine and the combination of dopamine and dobutamine were compared by using forty-two mongrel dogs in hemorrhagic shock states. The combined use of dopamine and dobutamine was considered to be the most effective in the treatment of hemorrhagic shock in view of the small increase in heart rate, the large and steady increase in cardiac output, the maintenance in renal arterial blood flow and the mild increase in peripheral resistance

DIAZEPAM-INDUCED SUPPRESSION OF JAW OPENING REFLEX IN RATS

Effect of an i.p. injection of diazepam on the jaw opening reflex evoked by electrical stimuli applied to the tooth pulp innervated by mainly high threshold afferents and the lower lip innervated by low threshold afferents was investigated using Wistar albino rats. Small doses of diazepam, less than 2.5 mg/kg, suppressed to the same degree the jaw opening reflexes evoked by stimulation of tooth pulp or lower lip. However, when larger doses than 5.0 mg/kg were administered, the suppression of tooth pulp evoked jaw opening reflex was greater than that of lower lip-evoked one. In this case, the period of suppression of tooth pulp-evoked jaw opening reflex was longer than that of lower lip evoked one. It is concluded that (1) the pain relieving effect of diazepam appears only when larger doses than 5.0 mg/ kg are administered and that (2) the pain-relieving effect lasts longer than muscle-relaxative effect of diazepam

AN EXPERIMENTAL STUDY ON THE EFFECT OF PLASMA EXPANDERS ON BLOOD COAGULABILITY

The effect of various plasma expanders on blood coagulation was studied using the thromboelastography (TEG). Solutions of 5, 10, 20, and 50% concentration of each expander (6% low molecular weight hydroxyethyl starch (6% Hespander®)*2, 3% dextran-40, 6% high molecular‘ weight hydroxyethyl starch (6 HES®)*3, and 6% dextran-70) or solvent (lactated Ringer solution and normal saline))) in blood were prepared and their coagulability was examined by TEG. In the low molecular weight plasma expanders (6% Hespander⑮ and 3% dextran 40), in general, the coagulability decreased when the concentration was increased. In the high molecular weight plasma expanders (6 HES® and 6% dextran-70), the coagulability increased slightly at low and high concentrations and the coagulability was reduced. As a conclusion, at clinically used concentrations of less than 20% in blood, changes in the TEG of the plasma expanders are minimum and have no clinical significance

FUNDAMENTAL STUDIES ON ELECTRIC STIMULATOR USED FOR ACUPUNCTURE ANALGESIA

In order to perform safe and effective electric stimulation in acupuncture analgesia or therapy, basic knowledge concerning the electric stimulator is required. If direct current is used, a negative square wave with a pulse duration of 0.5~1.5 msec should be applied to the needle electrode to perform elective stimulation. Negative current is more effective at lower amperage than positive current and the possible corrosion hazard by the positive current can be avoided

ANTAGONISM OF ACUPUNCTURE ANALGESIA BY NALOXONE IN UNCONSCIOUS MAN

The effects of acupuncture analgesia were studied using the change in halothane MAC in volunteers. Halothane MAC under electrical acupuncture stimulation was reduced to 86.2 ± 11.1% from the control value. After naloxone administration the level of the MAG was raised to the control level and the increment was 19.l ± 14.8%. Naloxone itself did not change the halothane MAC in the same subjects. These results suggest that the changes in halothane MAC under acupuncture stimulation are caused by the release of an endogenous analgesic substance in the brain