THE EFFECT OF LACTIC ACID ON THE RESPIRATORY CENTER

¹ Laboratory of Pharmacology and Therapeutics of the University of Illinois, College of Medicine, Chicago

1. Lactic acid, when injected intravenously in moderate doses, about 0.5 cc. of normal acid per body kiloweight, produces marked increase in respiratory rhythm, both in rate and amplitude.

2. This response is not specific for lactic acid, but may be produced by practically any organic or inorganic acid.

3. The mechanism of this hyperpnea probably involves three factors: (a) the acid may liberate CO₂ from the blood carbonates, and the excess CO₂ may play some part in the excessive movement; (b), the acid may act as a direct respiratory stimulant; (c), probably the most important factor, the acid sensitizes the respiratory center.

4. The author suggests that the reaction is most probably due to a synergistic action of the acid and CO₂ on the respiratory center.