Abstract
Gap junction proteins are expressed in the pre-Bötzinger complex of the respiratory network but it remains under discussion how they modulate the respiratory rhythm generation. In the present study we tested whether the gap junction blockers 18-β-glycyrrhetinic acid (18-βGA) and 18-α-glycyrrhetinic acid (18-α-GA) change either the phrenic nerve (PN) discharge frequency or amplitude. The PN discharge was recorded using the working heart-brainstem preparation of adult wistar rats (P22P28) exposed to increasing concentrations of the gap junction blockers (0.1; 1; 10; 20 μM). With the two lower concentrations (0.1; 1 μM) of 18-β-GA, PN discharge frequency decreased to 46±15% (p=0.007) of the control value while it increased to 173±57% (p=0.16) with the two higher concentrations (10; 20 μM). Surprisingly, with 18-α-GA the PN discharge frequency was not significantly changed with any of the concentrations used. Enhancing the respiratory drive with 12% CO2, the PN discharge frequency increased tendencially with rising concentrations of 18-β-GA, but again no significant change was observed with 18-α-GA. PN-amplitudes were slightly reduced over the course of the experiments, while the frequency of the heartbeat was not significantly changed at any time with any concentration.
| Original language | English |
|---|---|
| Pages (from-to) | 214-224 |
| Number of pages | 11 |
| Journal | Indian Journal of Physiology and Pharmacology |
| Volume | 57 |
| Issue number | 3 |
| Publication status | Published - Jul 2013 |
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Keywords
- 18-α-glycyrrhetinic acid
- Gap junction blockers
- Gap junctions
- Respiratory rhythm generation
- Working heart brainstem preparation
ASJC Scopus subject areas
- Physiology
- Pharmacology
- Physiology (medical)
Cite this
Modulation of the respiratory rhythm by gap-junction blockers 18-α-glycyrrhetinic acid and 18-β-glycyrrhetinic acid. / Juntermanns, Benjamin; Göpelt, Kirsten; Busselberg, Dietrich.
In: Indian Journal of Physiology and Pharmacology, Vol. 57, No. 3, 07.2013, p. 214-224.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Modulation of the respiratory rhythm by gap-junction blockers 18-α-glycyrrhetinic acid and 18-β-glycyrrhetinic acid
AU - Juntermanns, Benjamin
AU - Göpelt, Kirsten
AU - Busselberg, Dietrich
PY - 2013/7
Y1 - 2013/7
N2 - Gap junction proteins are expressed in the pre-Bötzinger complex of the respiratory network but it remains under discussion how they modulate the respiratory rhythm generation. In the present study we tested whether the gap junction blockers 18-β-glycyrrhetinic acid (18-βGA) and 18-α-glycyrrhetinic acid (18-α-GA) change either the phrenic nerve (PN) discharge frequency or amplitude. The PN discharge was recorded using the working heart-brainstem preparation of adult wistar rats (P22P28) exposed to increasing concentrations of the gap junction blockers (0.1; 1; 10; 20 μM). With the two lower concentrations (0.1; 1 μM) of 18-β-GA, PN discharge frequency decreased to 46±15% (p=0.007) of the control value while it increased to 173±57% (p=0.16) with the two higher concentrations (10; 20 μM). Surprisingly, with 18-α-GA the PN discharge frequency was not significantly changed with any of the concentrations used. Enhancing the respiratory drive with 12% CO2, the PN discharge frequency increased tendencially with rising concentrations of 18-β-GA, but again no significant change was observed with 18-α-GA. PN-amplitudes were slightly reduced over the course of the experiments, while the frequency of the heartbeat was not significantly changed at any time with any concentration.
AB - Gap junction proteins are expressed in the pre-Bötzinger complex of the respiratory network but it remains under discussion how they modulate the respiratory rhythm generation. In the present study we tested whether the gap junction blockers 18-β-glycyrrhetinic acid (18-βGA) and 18-α-glycyrrhetinic acid (18-α-GA) change either the phrenic nerve (PN) discharge frequency or amplitude. The PN discharge was recorded using the working heart-brainstem preparation of adult wistar rats (P22P28) exposed to increasing concentrations of the gap junction blockers (0.1; 1; 10; 20 μM). With the two lower concentrations (0.1; 1 μM) of 18-β-GA, PN discharge frequency decreased to 46±15% (p=0.007) of the control value while it increased to 173±57% (p=0.16) with the two higher concentrations (10; 20 μM). Surprisingly, with 18-α-GA the PN discharge frequency was not significantly changed with any of the concentrations used. Enhancing the respiratory drive with 12% CO2, the PN discharge frequency increased tendencially with rising concentrations of 18-β-GA, but again no significant change was observed with 18-α-GA. PN-amplitudes were slightly reduced over the course of the experiments, while the frequency of the heartbeat was not significantly changed at any time with any concentration.
KW - 18-α-glycyrrhetinic acid
KW - Gap junction blockers
KW - Gap junctions
KW - Respiratory rhythm generation
KW - Working heart brainstem preparation
UR - http://www.scopus.com/inward/record.url?scp=84884386370&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84884386370&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:84884386370
VL - 57
SP - 214
EP - 224
JO - Indian Journal of Physiology and Pharmacology
JF - Indian Journal of Physiology and Pharmacology
SN - 0019-5499
IS - 3
ER -