The Role of Carbonic Anhydrase in the Modulation of Central Respiratory-related pH/CO2 Chemoreceptor-stimulated Breathing in the Leopard Frog (Rana pipiens) Following Chronic Hypoxia and Chronic Hypercapnia

• Main Author: Srivaratharajah, Kajapiratha
• Other Authors: Reid, Stephen G.
• Format: Others
• Language: en_ca
• Published: 2008
• Subjects: Acetazolamide; Amphibian Respiration; Carbonic Anhydrase; Central pH/CO2 Chemoreceptors; Chronic Hypercapnia; Chronic Hypoxia; Fictive Breathing; In Vitro Brainstem-Spinal Cord Preparation; Leopard Frogs; 0433
• Online Access: http://hdl.handle.net/1807/17226

The aim of this thesis was to elucidate the role of carbonic anhydrase (CA) in the modulation of central pH/CO2-sensitive fictive breathing (measured using in vitro brainstem-spinal cord preparations) in leopard frogs (Rana pipiens) following exposure to chronic hypercapnia (CHC) and chronic hypoxia (CH). CHC caused an augmentation in fictive breathing compared to the controls (normoxic normocapnic). Addition of acetazolamide (ACTZ), a cell-permeant CA inhibitor, to the superfusate reduced fictive breathing in the controls and abolished the CHC-induced augmentation of fictive breathing. ACTZ had no effect on preparations taken from frogs exposed to CH. Addition of bovine CA to the superfusate did not alter fictive breathing in any group, suggesting that the effects of ACTZ were due to inhibition of intracellular CA. Taken together, these results indicate that CA is involved in central pH/CO2 chemoreception and the CHC-induced increase in fictive breathing in the leopard frog.