Comparative study of the activity of boric, benzene-boronic and methyl-benzene-boronic acids upon respiration, general metabolism and systemic hemodynamics of the anesthetized dog.

The authors compared the action of boric, benzene-boronic and p-methyl-benzene-boronic acids on respiration and general metabolism and on systemic hemodynamics of the anesthetized dog. They further investigated the effects on the arterial blood pressure in the rat and on the isolated rabbit heart. In the dogs, the three acids were shown to have no significant action on the systolic, diastolic and mean arterial blood pressures and a slight stimulating action on the differential arterial blood pressure. On the contrary, in the rat, all the acids were hypotensive. This action was dose dependent. In the entire animal, as well as in the isolated rabbit heart, benzene-boronic and p-methyl-benzene-boronic acids depressed the myocardial contractility. Whereas boric acid did not act on the heart contractility in situ in anesthetized dogs, it slightly stimulated the myocardial contractility of the isolated rabbit heart. The two acids seemed to be directly active on the myocardial cell. In the anesthetized dog, cardiac performances were first depressed then stimulated. Both benzene-boronic and p-methyl-benzene-boronic acids were ventilatory depressors: they reduced ventilatory output and rhythm, they first decreased then increased total O2 consumption and CO2 production.