[Temporal decay of the effect of a single vagal stimulation on cardiac rhythm in the rabbit]. / Decadimento temporale dell'effetto di singoli stimoli vagali sul ciclo cardiaco, nel coniglio.

The negative chronotropic effect of a single stimulus randomly delivered through right, left or both vagi respectively, within the cardiac cycle was studied in anaesthetized rabbits. The effect was analyzed on the P-P cycles subsequent the stimulus application, calculating percentagewise the delay observed in definite time-lapses, equalized to two pre-stimulus cycles. The results indicate that the efficacy of the negative chronotropic effect of vagal stimulation shows the least delay the closer the stimulus to the wave, while the delay is higher when the stimulus is delivered within the central portion of the cycle.

[Integration of the effects of a single stimulus applied to the vagus nerve on the right and the left, in the rabbit heart]. / Integrazione degli effetti di singoli stimoli applicati ai nervi vaghi di destra e di sinistra, nel cuore di coniglio.

It was reported by the literature that a train stimulation, simultaneously delivered on the two vagi, resulted in a decrement of the negative chronotropic effect, when it was compared to the sum of the effects obtained by the stimulation of the two nerves, separately. Our data indicate that the size of the chronotropic effect obtained by the simultaneous application on the two vagi of a single supraliminar stimulus, randomly applied within the P-P cycle, in rabbits, can be equal, higher or lower than the sum of the same stimulation separately delivered to the two nerves. The results could depend upon the different amount of acetylcholine released during stimulation. The hypothesis is put forward that different patterns of the neuro-cardiac junction regulation might be activated according to the quantity of released neuromediator.

[Analysis of proteins and glycoproteins from adult bovine cerebellum. II. Quantitative separation by Con A Sepharose chromatography]. / Analisi di proteine e glicoproteine del cervelletto di bovino adulto- Note II. Separazione quantitativa mediante colonna di ConA-Sefarosio.

Soluble and insoluble glycoproteins from adult bovine cerebellum have been separated by affinity chromatography on ConA-Sepharose and analyzed by polyacrylamide gel electrophoresis I2% in presence of SDS. Soluble fraction represents 26% of total proteins. Within soluble and insoluble fractions 4.5% of proteins binds to ConA. Electropherograms of the soluble and insoluble fractions as well as of the proteins not absorbed on ConA-Sepharose, display a very complex pattern. Soluble fractions present many sharp bands in the region of molecular weight above 100 k. Heterogeneity is lesser in ConA-binding proteins. The contamination by Concanavalin A is considered. At present no definite conclusions can be drawn regarding the similarities existing between s.c. soluble and membrane-bound cerebral glycoproteins.

[Analysis of cerebellar proteins and glycoproteins in adult cattle. I. Con A positive glycoproteins]. / Analisi di proteine e glicoproteine del cervelletto di bovino adulto. Nota I. Glicoproteine con A positive.

The cerebellar glycoproteins of bovine have been separated by affinity chromatography on Con A-Sepharose and analyzed by poliacrylamide gel electrophoresis. Some soluble Con A binding glycoproteins are common to the insoluble (membrane bound) glycoproteins suggesting a relationship between the two classes of molecules. The data support the hypothesis that some of the soluble glycoproteins can be considered precursors of the insoluble.