Effect of hypocapnia on ventral medullary blood flow and pH during hypoxia in cats
Ventral medullary blood flow was measured in 33 chloralose-urethan-anesthetized cats during 60 min of isocapnia-hypoxia, mild hypocapnia-hypoxia, or severe hypocapnia-hypoxia. In an additional group of six animals the pH of ventral medullary extracellular fluid (ECF) was determined during mild hypocapnia-hypoxia. The increase in blood flow during hypoxia was reduced by mild hypocapnia and eliminated by severe hypocapnia. With the exception of an initial decrease in ECF H(+) concentration, which occurred during the first 10 min of mild hypocapnia-hypoxia, ECF H(+) concentration increased progressively throughout the exposure and recovery periods and was significantly elevated from the control value by the first 10 min of the recovery period. The results suggest that hypocapnia affects the hypoxic cerebrovascular response of the ventral medulla and that this phenomenon could affect the regulation of ventral medudllary ECF H(+) concentration. 17 references.
- Research Organization:
- Texas Tech Univ., Lubbock
- OSTI ID:
- 6990373
- Journal Information:
- J. Appl. Physiol.: Respir., Environ. Exercise Physiol.; (United States), Vol. 61
- Country of Publication:
- United States
- Language:
- English
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