Role of peripheral tissue receptors in stimulation of ventilation by 2,4-dinitrophenol

Previous workers have demonstrated that hindlimb receptors can mediate some portion of the increase in VE elicited by 2,4-dinitrophenol (DNP). Liang and Hood have recently demonstrated that these hindlimb receptors communicate with the respiratory center via afferent pathways of the lumbar spinal cord. Accordingly, to determine the quantitative contribution of these hindlimb receptors to increases in VE elicited by DNP (4 mg/kg), we compared two groups of animals with respect to ventilatory, metabolic, and thermal responses elicited by this drug. Group I animals underwent complete transection of the spinal cord at the first lumbar level, whereas the spinal cord in Group II animals remained intact. Our results indicate that Group I and Group II animals did not differ with respect to increases in VE, VO2, and rectal temperature elicited by DNP. These results suggest that hindlimb receptors do not play an obligatory role in mediating increases in VE elicited by DNP. Therefore, these observations raise the possibility that multiple afferent pathways may exist for stimulation of VE by DNP.