Abstract: FR-PO381
Mechanosensitive Potassium Channels in the Afferent Limb of the Cardio-Renal Baroreflex
Session Information
- Hypertension and CVD: Basic
November 03, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Hypertension and CVD
- 1601 Hypertension and CVD: Basic
Authors
- Rodionova, Kristina, Friedrich-Alexander-Universitat Erlangen-Nurnberg, Erlangen, Bayern, Germany
- Ditting, Tilmann, Friedrich-Alexander-Universitat Erlangen-Nurnberg, Erlangen, Bayern, Germany
- Hilgers, Karl F., Friedrich-Alexander-Universitat Erlangen-Nurnberg, Erlangen, Bayern, Germany
- Schiffer, Mario, Friedrich-Alexander-Universitat Erlangen-Nurnberg, Erlangen, Bayern, Germany
- Amann, Kerstin U., Friedrich-Alexander-Universitat Erlangen-Nurnberg, Erlangen, Bayern, Germany
- Veelken, Roland, Friedrich-Alexander-Universitat Erlangen-Nurnberg, Erlangen, Bayern, Germany
- Linz, Peter, Friedrich-Alexander-Universitat Erlangen-Nurnberg, Erlangen, Bayern, Germany
Background
We have recently shown that the cardiorenal baroreflex (CRB) is impaired already in congestive heart failure with preserved ejection fraction. There might be a number of possibly involved mechano-sensitive channels and receptors in the afferent limb of the CRB. Since cardiac function is dependent on tight control of serum potassium levels, we tested the hypothesis that mechano-sensitive potassium channels are expressed in the afferent limb of the CRB.
Methods
We used inside-out-patches from cultured cardiac nodose ganglion neurons of rats that comprise the first neuron of the afferent limb of the CRB. The channels were activated by applying suction to the patch in a stepwise protocol.
Results
Using the pipette perfusion technique two MS channels could be distinguished: One could be blocked extracellularly with 10 µM gadolinium, a known blocker of MS ion channels. It exhibited a slope conductance of 116.4 ± 5.3 pS in symmetrical potassium concentrations. The other was not affected by gadolinium and had a slope conductance of 76.1 ± 6.5 pS. The channels exhibited also sodium- besides potassium-conductivity. The relative conductivity from potassium to sodium was 3.4 in both groups of channels, which allows membrane depolarization to levels where voltage-activated sodium-channels open.
Conclusion
Hence, through mechano-sensitive cation channels putatively also influenced by extracellular potassium concentrations, the CRB might indirectly influence serum potassium levels via altered salt and water excretion.