PGE2 concentrations in renal venous plasma and renal lymph during basal and stimulated conditions in the dog.

PGE2 concentration (pg/ml + SEM) was measured in canine renal lymph (394 +/- 115), renal venous plasma (276 +/- 55), arterial plasma (172 +/- 34) and urine (1290 +/- 934). Control periods were followed by an infusion of the sodium salt of arachidonic acid (AA) (40 micrograms/kg min) into the renal artery to stimulate prostaglandin synthesis. During infusion of AA PGE2 concentrations increased significantly in renal lymph (672 +/- 155) renal venous plasma (549 +/- 123), and urine (6768 +/- 1420), but not in the arterial plasma (176 +/- 31). Concentrations in renal lymph and renal venous plasma were not significantly different under either condition. These findings indicate that PGE2 concentration in renal venous plasma is, by and large, representative of mean PGE2 concentrations in the cortical renal interstitium, although focal inhomogeneities in PGE2 concentration in the different areas of the renal interstitium cannot be excluded. Since flow rate of renal lymph is insignificant in comparison with renal venous plasma flow rate total renal PGE2 output can be estimated from measurements in renal venous plasma and urine.