RESUMO
Arginine (0.8g/kg, ip) or a vehicle was administered to rats and the levels of arginine and a large number of related amino compounds++ were measured in plasma, heart, aorta, vena cava, pancreas and bronchi at specified time intervals. Arginine levels (nmol/ml) increased in the plasma from 237 to 3172 at 15 min, 1236 at 30 min and 509 at 120 min. Peak concentrations (nmol/g) of arginine are reached in the tissues at 15 or 30 minutes with control and postinjection values of 500 and 1769 in the heart, 314 and 1563 in the aorta, 575 and 2976 in the vena cava, 760 and 1943 in the bronchi, and 234 and 3638 in the pancreas. Arginine injection also affects a number of amino acids and related compounds in the plasma and tissues most notably ornithine, isoleucine, phosphoserine, leucine and ethanolamine. However, plasma level changes do not predict tissue level changes which are highly specific for an individual compound and tissue. There was no general indication that arginine injection stimulates nitric oxide (NO) formation in any tissue. Thus, arginine is rapidly absorbed from the abdominal cavity into the blood stream, is quickly taken up by the tissues studied and disappears after about 2 to 3 hours. The effects seen after arginine administration could be caused by arginine per se and/or changes in one or more of the related amino compounds but not by NO.
