Slow inotropic response of intact left ventricle to sudden dilation critically depends on a myocardial dialysable factor.
1. Slow inotropic response following a sudden myocardium stretch seems to be an autocrine/paracrine mechanism the basis of which is not yet completely defined. 2. We compared the canine left ventricle (LV) response to sudden dilation when the LV was supported by the arterial blood of a support dog with when it was supported by an oxygenator + haemodialyser system. 3. A slow inotropic response (SIR) after dilation was seen in all six hearts supported by the donor dog, attaining 87 +/- 6% of immediate increase, whereas a mere 10% SIR occurred in only one out of seven hearts maintained by the oxygenator + haemodialyser. 4. These results indicate that SIR genesis involves one or more renewable components essential to the intracellular calcium gain elicited by stretch.
Tucci
Paulo J F
PJ
Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, Brazil. pjtucci@uol.com.br
Faber
Cristiano N
CN
dos Santos
Leonardo
L
Antonio
Ednei L
EL
D000818:Animals; D019898:Autocrine Communication / Q000187:drug effects / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D015314:Dialysis Solutions / Q000737:chemistry / Q000494:pharmacology; D004108:Dilatation, Pathologic / Q000503:physiopathology*; D004285:Dogs; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology; D006321:Heart / Q000187:drug effects / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects / Q000502:physiology*; D010107:Oxygenators, Membrane; D019899:Paracrine Communication / Q000187:drug effects / Q000502:physiology; D010477:Perfusion / Q000379:methods; D006435:Renal Dialysis / Q000295:instrumentation / Q000379:methods; D014165:Transfer Factor / Q000737:chemistry / Q000494:pharmacology; D014325:Tromethamine / Q000008:administration & dosage / Q000494:pharmacology; D016277:Ventricular Function, Left / Q000187:drug effects / Q000502:physiology*; D017725:Ventricular Pressure / Q000187:drug effects / Q000502:physiology
D015314:Dialysis Solutions; C074097:Krebs-Henseleit solution; D014165:Transfer Factor; D014325:Tromethamine; D005947:Glucose