Details

Autor(en) / Beteiligte

• Agnisola, C
• Jensen, F B
• Tota, B
• Mustafa, T

Titel

Performance of the isolated rainbow trout heart perfused under self-controlled coronary pressure conditions: effects of high and low oxygen tension, arachidonic acid and indomethacin

Ist Teil von

• Journal of Comparative Physiology, A, 1998-03, Vol.168 (2), p.96-104

Erscheinungsjahr

1998

Quelle

SpringerLink

Beschreibungen/Notizen

• The effects of arachidonic acid (AA) and indomethacin (IM) on performance, oxygen consumption and lactate release of the trout heart were studied in vitro TPa s m super(-3) using a perfusion system, which allowed the evaluation of the integrated function of ventricle and coronary system by continuously setting the input coronary flow and pressure proportional to the pressure and flow output of the heart. The heart was working against a fixed resistance. A reduction of input oxygen partial pressure (P sub(O[sub]2)) from 175 torr (high P sub(O[sub]2)) to 76 torr (low P sub(O[sub]2)) increased the coronary flow (from 0.51 ml min super(-1) kg super(-1) to 1.21 ml min super(-1) kg super(-1), respectively) due to a strong reduction in coronary resistance (from 0.60 TPa s m super(-3) to 0.19 TPa s m super(-3), respectively). Oxygen consumption by the heart was significantly reduced from 20.7 ml min super(-1) g super(-1) at high P sub(O[sub]2) to 4.6 ml min super(-1) g super(-1) at low P sub(O[sub]2), while lactate production was increased from 24 mu mol h super(-1) g super(-1) to 42 mu mol h super(-1) g super(-1), indicating a higher contribution of anaerobic respiration to mechanical work. Mechanical efficiency was significantly higher at low than at high P sub(O[sub]2). Exogenous AA caused a depression of inotropism and a reduction in the aerobic metabolic rate (by 25-35%), which was not accompanied by increased lactate production. IM enhanced the depression of both inotropism and aerobic metabolism. The effect of AA and IM on the heart were amplified at low P sub(O[sub]2).