Distal colitis decreases the contractility of the underlying circular smooth muscle. We examined how time after injury and lesion severity contribute to the decreased contractility and how colitis alters the calcium-handling properties of the affected muscle. Distal colitis was induced in rats by intrarectal administration of 4% acetic acid. Contractile responses to acetylcholine, increased extracellular potassium, and the G protein activator NaF were determined for circular muscle strips from sham control and colitic rats at days 1, 2, 3, 7, and 14 postenemas. Acetylcholine stimulation of tissues from day 3colitic rats was performed in a zero calcium buffer, in the presence of nifedipine, and after depletion of intracellular stores of calcium. The colitis was graded macroscopically as mild, moderate, or severe. Regardless of agonist, maximal decrease in force developed 2 to 3 days posttreatment, followed by a gradual return to control by day 14. The inhibitory effect of colitis on contractility increased with increasing severity of inflammation. Limiting extracellular calcium influx had a greater inhibitory effect on tissues from colitic rats; intracellular calcium depletion had a greater inhibitory effect on tissues from control animals. The data suggest that both lesion severity and time after injury affect the contractile response of circular smooth muscle from the inflamed distal colon. Impaired utilization of intracellular calcium may contribute to the decreased contractility.

Ss were monitored for respiratory rate, pulse rate, blood pressure, skin resistance, EEG activity, and muscle activity. They were monitored during the alert state, meditation (TM or simple word type), hypnosis (relaxation and task types), and relaxation. Ss gave a verbal comparative evaluation of each state. The results showed singificantly better relaxation responses for the relaxation states (relaxation, relaxation-hypnosis, meditation) than for the alert state. There were no significant differences between the relaxation states except for the measure "muscle activity" in which meditation was significantly better than the other relaxation states. Overall, there were significant differences between task-hypnosis and relaxation-hypnosis. No significant differences were found between TM and simple word meditation. For the subjective measures, relaxation-hypnosis and meditation were significantly better than relaxation, but no significant differences were found between meditation and relaxation-hypnosis.

The hydrogen and fluorine nmr spectra of the fluorine bihalide ions FHX~( X = F, Cl, Br, and I) complete our study of the ten bihalide ions in aprotic solvents. The H-F coupling constant has been resolved in all four fluorine bihalides. Exchange of fluorine is slow; exchange of the other halogens is fast on the nmr time scale. The formation and interconversion equilibria may be adequately interpreted by assuming quantitative hydrogen transfer to the most basic (the smallest) halide ion in the system. Consistent with this, we find that the predominant complex in a solution of HC1 and excess Bris ClHBrnot BrHBras previously reported (Fujiwara and Martin, J. Chem. Phys., 56, 4091 (1972)); the proton shieldings in these ions are coincidentally the same. A heterobihalide ion XHYbehaves as an anion-molecule H-bonded complex XH • • • Y-, where is less than . A simple electrostatic interpretation of the charge shifts on H bonding appears adequate to account for the observed formation constants and hydrogen shieldings. It is possible to make predictions of the bond lengths

In weakly solvating media, the trihalomethanes associate specifically with the anions of tetraalkylammonium salts. The concentration and temperature dependence of the trihalomethane proton shielding has been (1) A

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