Strain differences in pH-sensitive K+ channel-expressing cells in chemosensory and nonchemosensory brain stem nuclei
| Autor: | Suzanne Neumueller, Hubert V. Forster, Denise Batuuka, Matthew R. Hodges, D. A. Riley, Paul Martino, Samantha Olesiak |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Male
medicine.medical_specialty Potassium Channels Physiology Biology Rats Inbred BN Physiology (medical) Internal medicine medicine Animals K channels Rats Inbred Dahl Strain (biology) Chemoreceptor Cells BROWN NORWAY Articles Carbon Dioxide Molecular biology Potassium channel Rats Endocrinology nervous system Control of respiration Female Brain Stem |
| Zdroj: | Journal of Applied Physiology. 117:848-856 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/japplphysiol.00439.2014 |
| Popis: | The ventilatory CO2 chemoreflex is inherently low in inbred Brown Norway (BN) rats compared with other strains, including inbred Dahl salt-sensitive (SS) rats. Since the brain stem expression of various pH-sensitive ion channels may be determinants of the CO2 chemoreflex, we tested the hypothesis that there would be fewer pH-sensitive K+ channel-expressing cells in BN relative to SS rats within brain stem sites associated with respiratory chemoreception, such as the nucleus tractus solitarius (NTS), but not within the pre-Bötzinger complex region, nucleus ambiguus or the hypoglossal motor nucleus. Medullary sections (25 μm) from adult male and female BN and SS rats were stained with primary antibodies targeting TASK-1, Kv1.4, or Kir2.3 K+ channels, and the total (Nissl-stained) and K+ channel immunoreactive (-ir) cells counted. For both male and female rats, the numbers of K+ channel-ir cells within the NTS were reduced in the BN compared with SS rats ( P < 0.05), despite equal numbers of total NTS cells. In contrast, we found few differences in the numbers of K+ channel-ir cells among the strains within the nucleus ambiguus, hypoglossal motor nucleus, or pre-Bötzinger complex regions in both male and female rats. However, there were no predicted functional mutations in each of the K+ channels studied comparing genomic sequences among these strains. Thus we conclude that the relatively selective reductions in pH-sensitive K+ channel-expressing cells in the NTS of male and female BN rats may contribute to their severely blunted ventilatory CO2 chemoreflex. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|