The Effect of Cushing's Syndrome Upon Serum Albumin Metabolism *

A BS TRA CT The metabolism of radioiodinated IgG was studied in a series of 42 patients with connective tissue diseases (16 systemic lupus erythematosus, nine rheumatoid arthritis, five polymyositis, five vasculitis, and seven miscellaneous diagnoses). Fractional catabolic rates were increased and survival half-lives were shortened in all diagnostic categories indicating hypercatabolism of IgG. This hypercatabolism was masked by increased IgG synthesis, resulting in elevated serum concentrations of IgG in patients with systemic lupus erythematosus and rheumatoid arthritis and in generally normal concentrations in the others.The metabolism of iodinated IgM was also studied in eight patients with systemic lupus erythematosus, in seven with rheumatoid arthritis, and in 12 controls. The fractional catabolic rates were normal in both groups of patients. Serum concentrations of both IgM and IgA were moderately elevated in all diagnostic categories. Serum albumin metabolism was entirely normal in the nine subjects studied who were not receiving corticosteroids; in three who were receiving them, moderate hypercatabolism was observed.The hypercatabolism of IgG could not be accounted for by factors previously known to alter IgG metabolism. It was not observed in 15 patients with other chronic, inflammatory diseases and was not explained by concomitant administration of adrenal corticosteroids to some patients. Identical results were obtained whether the IgG was obtained from a patient himself or from a normal donor, demonstrating that the hypercatabolism is a host defect and not an abnormality of the protein.

Section: Discussionmentioning

confidence: 72%

Hypercatabolism of normal IgG; an unexplained immunoglobulin abnormality in the connective tissue diseases

Wochner¹

1970

“…Results of paired and unpaired studies, using albumin-mI in patients without liver disease, normal volunteers, and normal rabbits, all of whom were assumed to be in a metabolically steady state, have indicated that the administration of corticosteroids or adrenal corticotrophic hormone and excessive endogenous secretion of corticosteroids in patients with Cushing's disease are associated with increased absolute catabolic rates of albumin, and hence by inference with increased absolute synthetic rates of this protein (17)(18)(19)(20).…”

Section: Resultsmentioning

confidence: 99%

Augmentation of albumin but not fibrinogen synthesis by corticosteroids in patients with hepatocellular disease

Cain¹,

Mayer²,

Jones³

1970

A B S T R A C T Simultaneous studies of albumin and fibrinogen metabolism have been conducted using the carbonate-14C method before and after a 13 day course of prednisolone in eight patients with hepatocellular disease. Initially six patients were hypoalbuminemic. The mean plasma albumin and fibrinogen concentrations and albumin and fibrinogen synthetic rates were all lower than the corresponding values in a group of control subjects. Prednisolone therapy was associated with significant increases in the plasma concentration and synthetic rate of albumin but changes in the intravascular albumin pools were not significant. It is inferred that a low synthetic rate of albumin in a patient with liver disease does not necessarily represent the maximum capacity of the diseased liver to synthesize this protein.Changes in the plasma concentration, intravascular pool, and synthetic rate of fibrinogen were small and inconsistent. The data are compatible with a selective action of corticosteroids on hepatic protein metabolism and with the existence of different mechanisms for the control of albumin and fibrinogen synthesis.

“…In phase 3, group B showed a fall in fractional catabolic rate with a rise in synthetic rate (Table III) Other factors, particularly hormonal, may affect the catabolic rate of albumin. Increased catabolism occurs in Cushing's disease and during the administration of cortisone and adrenocorticotrophin (ACTH) (31)(32)(33)(34). Similarly, an increased rate occurs in thyrotoxicosis and after administration of thyroid hormone and triiodothyronine (35,36,29).…”

Section: Discussionmentioning

confidence: 99%

Albumin metabolism: effect of the nutritional state and the dietary protein intake

James¹,

Hay²

1968

176

A B S T R A C T Nine malnourished and nine children who had recovered from malnutrition were given a single injection of albumin-131I and were studied during consecutive periods in which the dietary protein was changed.Malnourished children had significantly lower catabolic rates of albumin than had recovered children on the same protein intake. Both nutritional groups, however, showed a progressive fall in catabolic rate after 3-5 days on a low protein diet (0.7-1.0 g/kg per day), and the maximum effect was seen in the 2nd wk of low protein feeding. The catabolic rate could return to normal within 3 wk in a malnourished child fed 4 g of protein/kg per day.The albumin synthetic rate was measured by a computer technique suitable for nonsteady-state conditions. The synthetic rate in the malnourished groups (101 mg/kg per day) fed on a low protein diet was significantly lower than the rate in the recovered groups (148 mg/kg per day). The synthetic rate responded rapidly to a change in diet; when the rate fell, the intravascular albumin mass was maintained by two compensating mechanisms: (1) a net transfer of extravascular albumin into the intravascular pool; and (2) by a delayed fall in the catabolic rate. The net transfer of albumin into the intravascular compartment diminished as the catabolic rate fell.Adaptation to a low protein diet was associated with: (a) low synthetic and catabolic rates of albumin; (b) a reduced extravascular albumin mass;