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Electrocardiographic changes induced by Labetalol, a drug blocking alpha- and beta-adrenergic receptors, have been studied in 10 anesthetized rats. Authors observed that Labetalol has: 1) slightly negative chronotropic action; 2)slightly negative dromotropic action on both atrio-ventricular and intraventricular conduction; 3) effective antiarrhythmic and alpha-blocking action and, inconstantly, 4) the so-called "intrinsic sympathicomimetic action" (I.S.A.), typical of several beta-blocking drugs.

No modification, neither immediate nor late, was observed after the intravenous injection of high doses of the coenzymatic forms of thiamine and pyridoxine. On the contrary, after the injection of high doses of the coenzyme A, a sudden, conspicuous and brief (20-25") diminution of heart rate was observed. Such a phenomenon was much more marked and longer if, before the coenzyme A, a digitalic compound (desacetil-lanatoside C or digitoxin) was administered.

From the Authors' observations during this research, there emerges the fact that pindololo does not seem deprived of that cardiodepressive action, which is typical of all beta-blocking drugs.

The effect of Berus Viper's venom on human blood globular resistance with changing incubation conditions has been studied. Particularly venom's concentration (from 200 to 400 microgram/ml of blood), temperature (from 20 degrees C to 37 degrees C) and time (from 1/2h to 2h) have been changed. Time and temperature are important factors in haemolytic process development, instead venom's concentration behave like a factor not significantly haemolysis modifying.

The authors, having in a previous series of experiments observed that coenzyme A, administered intravenously in doses from 200 to 500 U.L., causes an immediate and transient decrease of the sinus rate, wanted to study to which part of the complex molecule of coenzyme A such effect is due. That's why they studied the action, intravenously, of pantothenic acid (200-400 mg/Kg), of cysteine (40-80 mg/Kg), of pantethein (40-100 mg/Kg) and of adenosine (4-10 mg/Kg). The results of the experiments demonstrate that the former bradycardia is due to adenosine, whereas the other substances have not this effect.

The activity of some clotting factors of human blood after incubation at 37 degrees C with Vipera berus venom (400 microgram/ml of plasma) has been measured. Factor V, initially, is activated by venom, but rapidly its activity decreases, becoming lower of that of controls and it exhausts oneself almost fully after 2 hours. Changes in the prothrombin and fibrinogen activity by venom action have not been noted.

Electrocardiographic changes induced by Verapamil, drug inducing inhibition of transmembrane movement of calcium into cardiac cells and mobilization of intracellular Ca++, have been studied in 10 anesthetized rats. Authors observed that Verapamil has: 1) negative chronotropic action on SA node; sometimes appears a superior nodal rhythm; 2) inconstantly, negative dromotropic action with prolonged atrioventricular conduction and "period of Luciani-Wenckebach'; 3) effective antiarrhythmic action; 4) no protective action towards peripheric vascular epinephrine effects; 5) remarkable negative inotropic action, whose Authors consider indirect signs the electrocardiographic changes, which indicate severe coronary failure, and the death of 6 rats by acute pulmonary edema.

The Author has, occasionally, registered in an old rat an "alternans" right bundle branch block. Assuming that, as in human pathology, such block is due to an increase of refractory period of the interested branch, the Author wanted to study the effect of substances which, acting in various ways, are able to eliminate the block. Adrenaline (10 mcg intravenously), because of its positive dromotropic action, improving the conduction, made, at first, disappear the block. Later, because of its direct positive chronotropic action and consequent increase of sinus rate, the block appears again and becomes stable. Later on, lowering sinus rate to the beginning values, the block becomes once again "alternans". A calcium-antagonist (verapamil, mg 0.10 intravenously), causing a decrease of sinus rate, makes the block disappear. The Author, by these observations, is induced to make some clinical considerations. This conduction disturbance is similar to that one which is observed in human pathology and which has always been treated successfully by vasodilators (best of all nicotinic acid), recently associated to antiaggregant drugs too.

Ethanol causes the hyperpolarization of the excitable membranes. In the Extensor Digitorum Longus (EDL) muscle of the rat the increase of resting membrane potential is 2-5% and is independent of the concentration of alcohol between 0.2 and 0.4 M, while at higher concentrations the membrane potential falls to levels equal or inferior to the normal potential. We have studied the hyperpolarization action of ethanol on the denervated muscle by crushing the sciatic nerve. Also under these conditions in which, as is known, there is a drop in the resting potential, ethanol causes hyperpolarization, however it is in general greater and it is dependent upon the concentration between 0.2 and 0.8 M.

In these experiments in the rat was studied the action of nicotine, administered intravenously in doses from 20 to 900 gamma/Kg. It was seen that, after the injection of lower doses, in the first phase there is always a more or less conspicuous diminution of the heart rate and a light and fleeting rise of the time of a-v conduction; there follows, after 25-30', a phase in which there is, as already noted, a rise of the heart rate. After higher doses was observed always an increase of the heart rate. Extrasystoles due to the action of nicotine was not observed. Sometime were observed signs of subendocardial damage or of fleeting right bundle-branch block. After a dose of 300 gamma (900 gamma/Kg) was observed a conspicuous and brief inhibition of sinus node activity and of the a-v conduction.

An investigation on eating habits of a group of 40 patients with beta-thalassemia major has been carried out mainly to evidentiate iron intake whose absorption is strikingly increased in this disease. Questionnaires were used to obtain information. Daily food intake, the mean consumption of various types of food and the level of the more significant nutrients were calculated, using the National Institute of Nutrition tables. A high consumption of meat and a low consumption of fruits and vegetables were observed. A high proportion of proteins (particularly of animal origin) and a low proportion of lipids and carbohydrates was observed in comparison with the recommended levels of nutrients. Iron intake was slightly lower but its absorption may be increased because of the high proportion of calories of animal origin. A manipulation of the diet seems to be necessary to reduce the risk of iron loading.

The effect of Berus viper's venom on the osmotic globular resistance of human blood, incubated for a period of 2 hours at 20 degrees C with amounts of venom in the range of 200 to 400 gamma/ml of blood, has been studied. The hemolytic effect occurs to a greater extent at NaCl concentrations higher than 0,60%.

We have studied the effects of the fluidizing action of ethanol on motor reinnervation in order to clarify if membrane fluidity changes affect synaptic plasticity and nerve regeneration. Sprague Dawley rats were denervated by crushing the sciatic nerve and subsequently, on the 16th day, the degree of reinnervation of the EDL muscle was observed by electrophysiological technique: in particular an observation was made of the resting potential and the m.e.p.p.s frequency by intracellular recordings in muscle fibers. During the nerve regeneration period, the rats were treated with 3 g of ethanol per kilogram of body weight per day. We have found that ethanol quickens the resting potential recovery but does not affect the m.e.p.p.s frequency.

Human blood hemolysis in NaCl 0,42% solution at 20 degrees C with different amounts of Berus Viper's venom in the range of 100 to 2000 microgram/ml of blood, has been studied. At these conditions venom's antihemolytic considerable action has been found.

Electrocardiographic changes induced by desacetil-lanatoside C and digitoxin, administered intravenously, have been studied in 25 anesthetized rats. No differences were observed between the actions of the two glucosides. Their negative chronotropic action can be effected with two mechanisms: one indirect, through vagal reflex, therefore immediate and, in general, brief; one direct, for direct action on the heart, which is gradual and long lasting. Their action on the a-v conduction is recorded by a rise in the duration of the P-Q tract, or, for higher doses, by blocking fenomena, which are brief and completely reversible. Signs of subendocardial damage are often observed, these too brief. The appearance of extrasystoles is rare.