Faculty Collaboration Database

Ventilatory compensation for lactacidosis in ponies: role of carotid chemoreceptors and lung afferents. J Appl Physiol (1985) 1991 Jun;70(6):2619-26

Date

06/01/1991

Pubmed ID

1909315

DOI

10.1152/jappl.1991.70.6.2619

Scopus ID

2-s2.0-0025829788 (requires institutional sign-in at Scopus site)   14 Citations

Abstract

We investigated changes in arterial PCO2 (PaCO2) and pulmonary ventilation (VE) in normal, carotid chemoreceptor-denervated, and hilar nerve-denervated ponies during intravenous lactic acid infusion at rest and treadmill exercise at 1.8 mph-5% grade (mild) and 1.8 mph-15% grade (moderate). Lactic acid, (0.5 M) infusion of 0.10, 0.13, and 0.20 ml.min-1.kg-1 at rest and mild and moderate exercise increased arterial [H+] linearly throughout the 10 min of acid infusion. At 10 min of infusion, arterial [H+] had increased approximately 20 nmol/l (0.2 pH units) for each condition and group. Under most conditions, the temporal pattern of PaCO2 during acid infusion was biphasic. At rest and during mild exercise in all groups, and in carotid chemoreceptor-denervated ponies during moderate exercise, PaCO2 increased approximately 2 Torr (P less than 0.05) during the first 2 min of acid infusion. However, in normal ponies during moderate exercise, PaCO2 was not changed from control in the first 2 min of infusion. Between 2 and 10 min of infusion at rest and mild and moderate exercise in all groups, there was a 5-Torr significant decrease in PaCO2, which did not differ (P greater than 0.10) between groups. VE increased between 15-30 s and 2 min of infusion, but VE changed minimally between 2 and 10 min of infusion at rest and exercise in all groups of ponies. We conclude that lactacidosis does increase VE at rest and submaximal exercise in the pony.(ABSTRACT TRUNCATED AT 250 WORDS)

Author List

Erickson BK, Forster HV, Pan LG, Lowry TF, Brown DR, Forster MA, Forster AL

Author

Hubert V. Forster PhD Professor in the Physiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Acidosis, Lactic
Afferent Pathways
Animals
Carbon Dioxide
Carotid Body
Chemoreceptor Cells
Denervation
Horses
Hydrogen-Ion Concentration
Hyperventilation
Lung
Physical Exertion
Respiration
Respiratory Transport