Abstract

Ventilatory sensitivity to hypercapnia is greater in Dahl salt‐sensitive (SS) rats than in Brown Norway (BN) inbred rats (J Appl Physiol). Since pH‐sensitive potassium ion (K+) channels are located within various chemosensitive nuclei including the nucleus of the solitary tract (NTS), and are postulated to contribute to CO2− H+ detection/signaling in chemosensitive neurons, we tested the hypothesis that there are more pH‐sensitive Kv 1.4 channel‐immunoreactive (ir) neurons within the NTS of SS than within the NTS of BN rats. The medullary sections (25 μm) containing the NTS from male and female BN and SS rats were stained with cresyl violet or with antibodies targeting Kv 1.4. Kv 1.4 channel‐ir neurons were quantified and compared with the total neurons in the region. The average number of Kv 1.4 channel‐ir neurons per hemisection was significantly (P < 0.05) greater in both male and female SS (n = 6 males and 6 females) than in the BN (n = 6 males and 6 females) rats. In addition, the percentage of Nissl stained neurons that express Kv 1.4 was statistically greater in SS male versus BN male rats. That trend however, was not observed in female SS and BN rats (P > 0.05). Our findings further support the hypothesis that a greater number of K+ channel‐ir neurons in the NTS of SS may contribute to their relatively greater sensitivity to CO2. (Supported by the Department of Veterans Affairs and NIH HL25739)

Full Text

Published Version

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.