[The effectiveness of trapidil and some derivatives on heart function under in vitro and in vivo conditions].
Cardiac and coronary effects of trapidil (Rocornal) and some derivatives were investigated in isolated heart preparations and rabbit hearts in vivo. All substances showed a comparable increase of the coronary flow. Contrary to the cardiotonic influence of trapidil the trapidil derivates induced a negative inotropic effect, possibly due to a weak calcium antagonism. Heart rate was slightly diminished, but in some cases higher doses caused an acute tachycardia. I.v. application of the substances to rabbits in doses of 10 mg/kg and 30 mg/kg induced an initial depression of blood pressure normalizing within 3-5 min. An increase of the myocardial prostacyclin biosynthesis is only demonstrable under trapidil. The results indicate that the cardiac effects of trapidil derivatives are possibly caused by a direct influence on the contractile system and the membrane potential of the cardiac muscle cell.
Mentz
P
P
Institut für Pharmakologie und Toxikologie, Martin-Luther-Universität Halle-Wittenberg.
Pawelski
K E
KE
Orlova
Z R
ZR
Giessler
C
C
Mest
H J
HJ
D000758:Anesthesia; D000818:Animals; D004558:Electric Stimulation; D011464:Epoprostenol / Q000096:biosynthesis; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D009206:Myocardium / Q000378:metabolism; D010477:Perfusion; D011743:Pyrimidines / Q000494:pharmacology*; D011817:Rabbits; D014192:Trapidil / Q000031:analogs & derivatives / Q000494:pharmacology*
D011743:Pyrimidines; D011464:Epoprostenol; D014192:Trapidil
Zur Wirksamkeit von Trapidil und einiger Derivate auf die Herzfunktion unter In-vitro- und In-vivo-Bedingungen.