PMID- 11005647
OWN - NLM
STAT- MEDLINE
DCOM- 20010201
LR  - 20141120
IS  - 0031-6768 (Print)
IS  - 0031-6768 (Linking)
VI  - 440
IP  - 5 Suppl
DP  - 2000
TI  - Nicardipine dose-dependently reduces the effect of equinatoxin II on coronary 
      flow in isolated porcine heart.
PG  - R145-6
AB  - Death after i.v. administration of equinatoxin II (EqT II) has been attributed to 
      the circulatory failure resulting from cardiotoxic effects. The mechanism of 
      action is unknown. The aim of the present work was to study the effects of the 
      toxin on vascular tone in the isolated porcine coronary artery and on coronary 
      flow in the isolated pig heart. EqT II caused concentration-dependent 
      contractions of rings of the isolated epicardial porcine coronary artery with an 
      EC50 value of 89+/-5 nM (n=5-6) and maximal effect of about 140% of the 
      contraction induced by 20 nM KCl. On Langendorffs porcine heart preparation EqT 
      II caused a dose-dependent decrease of coronary flow. At EqT II doses lower than 
      0.05 micromol/100 g of heart weight there were no measurable effects of the 
      toxin. At dose 0.5 micromol/100 g the toxin decreased coronary flow to less than 
      9.8+/-2.5% of the control value. The constrictory effect of the toxin on isolated 
      porcine coronary arteries was diminished by the L-type calcium channel antagonist 
      nicardipine (NC). NC in 1 microM concentration almost completely abolished the 
      effect of EqT II on coronary flow. Our results confirmed involvement of L-type 
      calcium channels in the vasoconstrictory effects of EqT II on epicardial coronary 
      arteries.
FAU - Drevensek, G
AU  - Drevensek G
AD  - Dept. of Pharmacol. & Exp. Toxicol., Ljubljana, Slovenia.
FAU - Budihna, M V
AU  - Budihna MV
FAU - Suput, D
AU  - Suput D
FAU - Bunc, M
AU  - Bunc M
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - Germany
TA  - Pflugers Arch
JT  - Pflugers Archiv : European journal of physiology
JID - 0154720
RN  - 0 (Cnidarian Venoms)
RN  - 0 (Vasoconstrictor Agents)
RN  - 0 (Vasodilator Agents)
RN  - 54578-46-0 (equinatoxin)
RN  - 660YQ98I10 (Potassium Chloride)
RN  - CZ5312222S (Nicardipine)
SB  - IM
MH  - Animals
MH  - Cnidarian Venoms/*antagonists & inhibitors/*pharmacology
MH  - Coronary Circulation/*drug effects
MH  - Dose-Response Relationship, Drug
MH  - Heart/drug effects
MH  - In Vitro Techniques
MH  - Nicardipine/*pharmacology
MH  - Osmolar Concentration
MH  - Potassium Chloride/pharmacology
MH  - Swine
MH  - Vasoconstrictor Agents/*pharmacology
MH  - Vasodilator Agents/*pharmacology
EDAT- 2000/09/27 11:00
MHDA- 2001/02/28 10:01
CRDT- 2000/09/27 11:00
PHST- 2000/09/27 11:00 [pubmed]
PHST- 2001/02/28 10:01 [medline]
PHST- 2000/09/27 11:00 [entrez]
PST - ppublish
SO  - Pflugers Arch. 2000;440(5 Suppl):R145-6.