Investigation of usefulness of electroreticulograms obtained from the sheep body surface in estimation of reticulum electrical activity.

The experiments were carried out on 3 sheep with one pair of platinum electrodes chronically implanted in the reticulum wall. The reticulum action potentials were recorded simultaneously from the body surface (using the needle electrodes placed subcutaneously) and from the implanted electrodes using an electroencephalograph Reega XVI Duplex TR. It was found that the two- or three-phase deflections on the electroreticulograms obtained from the body surface were exactly correlated with the series of potential spikes on the records from the implanted electrodes.

[Effect of dopamine on cecum motility in sheep].

The influence of dopamine on the motility of the caecum were studied. The experiments were carried out on 4 sheep with chronic fistulas of the caecum. The contractions of the caecum were recorded by the balloon method.

Sialic acid at the surface of myocardial cells during embryonic development.

We tested the hypothesis that the reduction of automaticity during the embryonic development of chick ventricular myocytes is correlated with the number of sialic acid residues at the cell surface. The major findings were twofold. First, the sialic acid content of ventricular tissue fragments declined during the period between 4 and 17 days of development; however, when a 26% reduction of cell surface area was taken into account, the surface density of sialic acid at 7 and 17 days was not significantly different.

[Effect of dopamine on small-intestinal motility in sheep].

The receptors involved in dopamine effect on the motility of the ileum were studied. The experiments were carried out on 3 sheep with chronic fistulas of the ileum and rumen. The contractions of the fistulated parts of the alimentary tract were recorded by the balloon method.

Highly enriched preparations of cultured myocardial cells for biochemical and physiological analyses.

Cultures of enzyme-dissociated myocardial cells contain myocytes as well as other cell types (e.g. fibroblasts); therefore, cell separation is necessary to interpret accurately biochemical measurements of substances or physiological measurements of processes common to more than one type of cell.