Tags

Type your tag names separated by a space and hit enter

Effect of dipfluzine on L-type calcium current in guinea pig ventricular myocytes.
Acta Pharmacol Sin. 2001 Aug; 22(8):701-5.AP

Abstract

AIM

To study the effect of dipfluzine (Dip) on L-type calcium current in guinea pig ventricular myocytes.

METHODS

Single myocytes were dissociated by enzymatic dissociation method. The current was recorded with the whole-cell configuration of the patch-clamp technique.

RESULTS

Dip (0.3 - 30 micromol/L) reduced the voltage-dependently activated peak value of I(Ca-L) in a concentration-dependent manner. The characteristics of I-V relationship were not greatly altered by Dip, and the maximal activation voltage of I(Ca-L) in the presence of Dip was not different from that of control. Steady-state activation of I(Ca-L) was not affected markedly, and the half activation potential V(0.5)) and the slope factor (kappa) in the presence of Dip 3 micromol/L were not markedly different from those of the control. V(0.5) value was (-12.8 +/- 1.7) mV in the control and (-13.2 +/- 2.4) mV in the presence of Dip 3 micromol/L. The kappa value was (7.1 +/- 0.4) mV in the control and (7.5 +/- 0.5) mV in the presence of Dip 3 micromol/L (n = 7 cells from 3 hearts, P > 0.05). Dip 3 micromol/L markedly shifted the steady-state inactivation curve of I(Ca-L) to the left, and accelerated the voltage-dependent steady-state inactivation of calcium current. V(0.5) value was (-19.7 +/- 2.4) mV in the control and (-31 +/- 6) mV in the presence of Dip 3 micromol/L. The kappa value was (3.6 +/- 0.3) mV in the control and (1.8 +/- 0.2) mV in the presence of Dip 3 micromol/L (n = 4 cells from 2 hearts, P < 0.05). Dip 3 micromol/L markedly delayed half-recovery time of Ca2+ channel from inactivation from (40 +/- 11) to (288 +/- 63) ms (n = 4, P < 0.01).

CONCLUSION

Dip mainly acts on the inactivated state of L-type calcium channel, accelerates the inactivation of calcium channel, and slows the recovery of calcium channel from inactivated state in guinea pig ventricular myocytes, through which the I(Ca-L) is inhibited.

Authors+Show Affiliations

Zhang YJ
Department of Physiology, Hebei Medical University, Shijiazhuang 050017, China.
Li DP
No affiliation info available
Xue BJ
No affiliation info available
Wang YL
No affiliation info available
He RR
No affiliation info available

MeSH

AnimalsCalcium Channel BlockersCalcium Channels, L-TypeCell SeparationCinnarizineFemaleGuinea PigsHeart VentriclesMaleMembrane PotentialsMyocytes, CardiacPatch-Clamp Techniques

Pub Type(s)

Journal Article

Language

eng

PubMed ID

11749841

Citation

Zhang, Y J., et al. "Effect of Dipfluzine On L-type Calcium Current in Guinea Pig Ventricular Myocytes." Acta Pharmacologica Sinica, vol. 22, no. 8, 2001, pp. 701-5.
Zhang YJ, Li DP, Xue BJ, et al. Effect of dipfluzine on L-type calcium current in guinea pig ventricular myocytes. Acta Pharmacol Sin. 2001;22(8):701-5.
Zhang, Y. J., Li, D. P., Xue, B. J., Wang, Y. L., & He, R. R. (2001). Effect of dipfluzine on L-type calcium current in guinea pig ventricular myocytes. Acta Pharmacologica Sinica, 22(8), 701-5.
Zhang YJ, et al. Effect of Dipfluzine On L-type Calcium Current in Guinea Pig Ventricular Myocytes. Acta Pharmacol Sin. 2001;22(8):701-5. PubMed PMID: 11749841.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effect of dipfluzine on L-type calcium current in guinea pig ventricular myocytes. AU - Zhang,Y J, AU - Li,D P, AU - Xue,B J, AU - Wang,Y L, AU - He,R R, PY - 2001/12/26/pubmed PY - 2004/1/13/medline PY - 2001/12/26/entrez SP - 701 EP - 5 JF - Acta pharmacologica Sinica JO - Acta Pharmacol Sin VL - 22 IS - 8 N2 - AIM: To study the effect of dipfluzine (Dip) on L-type calcium current in guinea pig ventricular myocytes. METHODS: Single myocytes were dissociated by enzymatic dissociation method. The current was recorded with the whole-cell configuration of the patch-clamp technique. RESULTS: Dip (0.3 - 30 micromol/L) reduced the voltage-dependently activated peak value of I(Ca-L) in a concentration-dependent manner. The characteristics of I-V relationship were not greatly altered by Dip, and the maximal activation voltage of I(Ca-L) in the presence of Dip was not different from that of control. Steady-state activation of I(Ca-L) was not affected markedly, and the half activation potential V(0.5)) and the slope factor (kappa) in the presence of Dip 3 micromol/L were not markedly different from those of the control. V(0.5) value was (-12.8 +/- 1.7) mV in the control and (-13.2 +/- 2.4) mV in the presence of Dip 3 micromol/L. The kappa value was (7.1 +/- 0.4) mV in the control and (7.5 +/- 0.5) mV in the presence of Dip 3 micromol/L (n = 7 cells from 3 hearts, P > 0.05). Dip 3 micromol/L markedly shifted the steady-state inactivation curve of I(Ca-L) to the left, and accelerated the voltage-dependent steady-state inactivation of calcium current. V(0.5) value was (-19.7 +/- 2.4) mV in the control and (-31 +/- 6) mV in the presence of Dip 3 micromol/L. The kappa value was (3.6 +/- 0.3) mV in the control and (1.8 +/- 0.2) mV in the presence of Dip 3 micromol/L (n = 4 cells from 2 hearts, P < 0.05). Dip 3 micromol/L markedly delayed half-recovery time of Ca2+ channel from inactivation from (40 +/- 11) to (288 +/- 63) ms (n = 4, P < 0.01). CONCLUSION: Dip mainly acts on the inactivated state of L-type calcium channel, accelerates the inactivation of calcium channel, and slows the recovery of calcium channel from inactivated state in guinea pig ventricular myocytes, through which the I(Ca-L) is inhibited. SN - 1671-4083 UR - https://www.unboundmedicine.com/medline/citation/11749841/Effect_of_dipfluzine_on_L_type_calcium_current_in_guinea_pig_ventricular_myocytes_ DB - PRIME DP - Unbound Medicine ER -