Hepatic blood flow and energy metabolism during hypotension induced by prostaglandin E1 and nicardipine in rabbits: an in vivo magnetic resonance spectroscopic study.

Hepatic blood flow (HBF) and energy metabolism during moderate hypotension induced by prostaglandin E1 (PGE1) and nicardipine were studied by in vivo magnetic resonance spectroscopy. HBF was determined by the deuterated water clearance method by using deuterium magnetic resonance spectroscopy, and energy metabolism was estimated from the changes in the levels of adenosine triphosphate and inorganic phosphate by using phosphorus (31P) magnetic resonance spectroscopy. Mean arterial blood pressure was intentionally reduced to 60% of control with PGE1 (n = 5) or nicardipine (n = 5). The HBF decreased by 38% and by 50% during the hypotension induced by PGE1 and nicardipine, respectively. The level of adenosine triphosphate decreased by 12% and that of inorganic phosphate increased by 80% during nicardipine-induced hypotension, whereas the corresponding levels showed no remarkable changes during PGE1-induced hypotension. After the cessation of drug administration, mean arterial blood pressure and HBF recovered to the control levels in the PGE1 group, but not completely in the nicardipine group. In the latter group, the level of inorganic phosphate did not recover either. These results indicate that during hypotension induced with PGE1 hepatic circulation and metabolism are conserved to a greater extent than during hypotension induced with nicardipine.