Gadolinium and mechanotransduction of rat aortic baroreceptors
Andresen, MC; Yang, M
HERO ID
3056525
Reference Type
Journal Article
Year
1992
Language
English
PMID
| HERO ID | 3056525 |
|---|---|
| In Press | No |
| Year | 1992 |
| Title | Gadolinium and mechanotransduction of rat aortic baroreceptors |
| Authors | Andresen, MC; Yang, M |
| Journal | American Journal of Physiology |
| Volume | 262 |
| Issue | 5 Pt 2 |
| Page Numbers | H1415-H1421 |
| Abstract | The cellular mechanisms enabling baroreceptors to transduce wall distortion into axonal discharge are unknown but might involve stretch-activated ion channels. Gadolinium (Gd3+, 10 microM) blocks stretch-activated channels in several preparations. Here we tested Gd3+ effects on discharge responses of 15 single-fiber baroreceptors in vitro. We simultaneously measured discharge, pressure, and aortic diameter at Gd3+ concentrations from 0.001 to 400 microM. High levels of Gd3+ added to a bicarbonate-buffered perfusate (Krebs) slightly shifted the pressure-discharge relation (less than 4 mmHg, n = 3, P = 0.01) without affecting slope or discharge frequency at threshold. Gd3+ in Krebs variably altered the pressure-diameter relation. Because 500 microM Gd3+ produced visible precipitate in Krebs, we tested Gd3+ in a simpler perfusate using N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES). Gd3+ in HEPES (n = 10) induced minor, but statistically significant, average increases in threshold (less than +5-7%) and no changes in gain. However, prolonged HEPES exposure alone (n = 2) produced similar shifts. Electron microscopy verified that Gd3+ diffused from the lumen to reach extracellular locations near baroreceptor endings. We conclude that 1) HEPES perfusate alone reversibly depresses baroreceptor discharge and 2) Gd3+ has no direct effects on baroreceptors. Thus it appears that aortic baroreceptor mechanotransduction must utilize a different class of stretch-activated ion channels. |
| Doi | 10.1152/ajpheart.1992.262.5.H1415 |
| Pmid | 1590446 |
| Wosid | WOS:A1992HV37200015 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |
| Keyword | PRESSORECEPTORS; STRETCH-ACTIVATED CHANNELS; MECHANORECEPTORS; LANTHANIDES; SENSORY TRANSDUCTION; N-2-HYDROXYETHYLPIPERAZINE-N'-2-ETHANESULFONIC ACID |