Effect of some drugs on human appendix in vitro.

Muscarinic action of acetylcholine was demonstrated in the human isolated appendix. Histamine-induced contractions seemed to the mediated by H1 receptors. Nicotine and DMPP-induced contractions were mediated through their action on ganglion cells. Experiments with adrenergic drugs suggested the presence of beta receptors.

Some photoresponses of isolated tissue preparations to ultraviolet light in the presence of photosensitizers.

Responses of isolated tissue preparations to ultraviolet (UV) light were studied with and without the presence of photosensitizers like eosin, fluorescein and sodium nitrite. Exposure to UV light in the presence of sodium nitrite induced consistent relaxation of rat duodenum. The photorelaxation was found to be related to the concentration of sodium nitrite. Adrenergic or cholinergic mechanisms do not seem to be involved. The isolated rat duodenum preparation exhibited quantitatively consistent photoresponse for 3 to 4 hr at its normal tone obviating the need for additional spasmogens as needed with other preparations. The preparation is a suitable test model for the study of photobiologic response evoked by UV light.

A preliminary report on the antiarrhythmic action of some newly synthesized glutarimide compounds.

The effects of a new series of glutarimide compounds have been studied in acetylcholine induced auricular fibrillation in anaesthetized cats and epinephrine induced ventricular arrhythmmias in conscious pigeons. Some of the compounds showed varying degree of protective action against experimental arrhythmias. However these compounds were found to be less potent than quinidine. The mechanism of antiarrhythmic action has been discussed.