Bromsulphthalein and indocyanine green elimination from plasma, and urinary bromsulphthalein excretion, in normal cats.

The elimination of bromsulphthalein (BSP) and indocyanine green (ICG) from plasma and urinary excretion of BSP were investigated in healthy cats. At 5 mg kg-1, BSP elimination fitted a two-compartment open model, with mean t1/2 beta of 7.1 (SD 2.5) minutes. A tendency for slower elimination of BSP at 10 mg kg-1 suggested saturation of excretory mechanisms, while at 2 mg kg-1 accurate dosing and assay of low BSP concentrations were difficult. Urinary recovery of BSP at 5 mg kg-1 was 0.01 to 0.13 per cent of the total dose. Plasma ICG (0.5 mg kg-1) data fitted a one-compartment open model, with mean t1/2 2.7 (SD 1.0) minutes. In cats, retention tests are more attractive than clearance tests because fewer blood collections are necessary. Proposed reference values are under 3.6 per cent retention of BSP (5 mg kg-1) at 30 minutes and under 17.5 per cent retention of ICG (0.5 mg kg-1) at 15 minutes. At present economic and technical factors favour BSP over ICG.

Urinary excretion of dye in dogs infused with BSP or its glutathione conjugate.

Renal clearance of BSP compounds was investigated in dogs during infusion of sulfobromophthalein (BSP) or its glutathione conjugate (BSP-GSH). Conjugated BSP compounds are more readily excreted into urine than unconjugated BSP. Dye clearance into urine was much less than simultaneously measured inulin clearance. This suggests that protein binding of BSP compounds significantly retards the glomerular filtration of the dye. BSP was found to bind more avidly to albumin than BSP-GSH. The ratio of dye clearance to inulin clearance remained relatively constant over a broad range of plasma concentrations of dye. The data support but do not prove glomerular filtration of non-protein-bound dye as the major mechanism accounting of urinary elimination of BSP compounds in the dog.

Extrahpetic distribution of sulfobromophthalein.

Plasma clearance of sulfobromophthalein (BSP) is widely used as a measure of hepatic function. Its validity depends upon its exclusive elimination from the body via bile. For example, in the present study, when BSP was administered intravenously (i.v.) to rats at four different doses (18.75, 37.5, 75, and 150 mg/kg), less than 0.5% of each dose was excreted into the urine and between 70 and 85% was excreted into the bile within 6 h after administration. It has been assumed that the distribution of BSP is limited to the blood and liver witith very little appearing in other tissues. When we measured the amount of BSP in the plasma, liver, and the bile 10 min after the i.v. administration of either a high (150 mg/kg) or a low (18.75 mg/kg) dose of BSP, only 60% of the dose was accounted for. The concentration of BSP and 12-I-labelled albumin (RISA) was measured in various tissue samples 10 min after administration of 17.5 or 150 mg of BSP or RISA per kilogram. More BSP was found in all tissues than was contained in the plasma entrapped therein. Thus, the distribution of BSP is not limited to the liver and plasma. During excretion BSP leaves other tissue (kidney, spleen, lung, etc.) and is ultimately excreted into the bile.

Liver disease in rheumatoid arthritis and Sjøgren's syndrome. Prospective study using biochemical and serological markers of hepatic dysfunction.

Inter-relationships of biochemical and immunological tests of liver function have been studied in a prospective study of 216 patients with rheumatoid arthritis (RA), 32 patients with Sjogren's syndrome, and 27 patients with the sicca syndrome, and these results have been compared with those obtained 289 patients with osteoarthrosis or with a form of seronegative polyarthropathy. In general the prevalence of abnormalities in serum alkaline phosphatase, bromsulphthalein excretion, smooth muscle antibody, and mitochondrial antibody in the former three groups was higher than in patients with osteoarthrosis. Patients with Sjogren's syndrome with RA had a higher prevalence of abnormalities of bromsulphthalein excretion, salivary duct antibody than patients with the sicca syndrome. Patients with RA had a higher pervalence of rheumatoid factor than those with the sicca syndrome. Patients with a positive smooth muscle or mitochondrial antibody were found to have a higher prevalence of hepatomegaly and splenomegaly, of abnormal liver function tests, of other autoantibodies, and of histological abnromalitis of liver than those in whom these tests were negative.

Biliary excretion of conjugated sulfobromophthalein (BSP) in constitutional conjugated hyperbilirubinemias.

Sulfobromophthalein (BSP) and its three major forms of conjugates were determined in bile or duodenal aspitate, plasma and urine following intravenous administration of free BSP and synthetic BSP-glutathione (BSP-GSH) in five patients with the Dubin-Johnson syndrome and two patients with the Rotor syndrome, using alumina column chromatography. It was found that in Dubin-Johnson patients the biliary excretion of conjugated BSP was selectively impaired, conjugated BSP increased in plasma replacing free BSP after 30 min, and plasma retention of BSP-GSH was greater than that of free BSP when administered intravenously. In contrast, biliary excretion of BSP and its conjugates was not impaired and regurgitation of conjugated BSP into plasma was minimal in the Rotor syndrome. Thus, these two constitutional hyperbilirubinemias can be separated by their basic defects in BSP metabolism.