Hepatic Excretory Function

Increases in hepatic excretory function also may take place. After the chronic administration of either pheno-barbital or the potassium-sparing diuretic spirono-... 

G23. Cohen, E. S., Althausen, T. L., and Giansiracusa, J. E., Studies on bromsulphthalein excretion, iv. Variation in the mechanism of hepatic excretory function when challenged with different dyes. Gastroenterology 30, 232-243 (1956). 

Schmidt, M. L., Garner, L. M., and Arias, I. M., Studies of hepatic excretory function. HI. Effect of hypopituitarism on the hepatic excretion of sulfobromophthalein sodium in man. Gastroenterology 62, 998-1002 (1967). 

Despoponlos, A. Kopp, A. Simms, Q. Congruence of renal and hepatic excretory functions. Sulfonic acid dyes. Am. J. Physiol. 1971, 220, 1755-1758. 

In addition, the liver synthesizes and excretes bile acids (Setchell and O Connell, 2001). Bile acid synthesis, the bile acid pool, and intralumenal bile acid concentrations gradually increase during the first year of life. Bile acid secretion is maximal at birth and cannot be further stimulated. This function of the liver can be assessed by quantifying blood levels of liver-derived enzymes as a marker of hepatocyte integrity, by quantifying blood levels of bile acids and isotope excretion scans as a marker of hepatic excretory function, and by measuring serum levels of specific drugs and their metabolites (Batres and Mailer, 2001). 

A dye which can be used in a similar manner to bromsulph thalein to test hepatic excretory function. 

Cardiac index and blood pressure must be sufficient to ensure adequate organ perfusion, as assessed by alert mental status, creatinine clearance sufficient to prevent metabolic azotemic complications, hepatic function adequate to maintain synthetic and excretory functions, a stable heart rate and rhythm, absence of ongoing myocardial ischemia or infarction, skeletal muscle and skin blood flow sufficient to prevent ischemic injury, and normal arterial pH (7.34 to 7.47) with a normal serum lactate concentration. These goals are most often achieved with a cardiac index greater than 2.2 L/min/m2, a mean arterial blood pressure greater than 60 mm Hg, and PAOP of 25 mm Hg or greater. 

However, the physiology of ageing includes poorer gastrointestinal absorption, somewhat reduced hepatic drug metabolism, and, commonly, a loss of lean body mass. While all of these have been documented, none is of as great a significance as the loss of renal excretory function which is invariably present in old age. 

Among the different roles previously described, the liver exerts an excretory function, being involved in the formation of bile, which drains into the small intestine. Bile salts in the bile play an important role as emulsifying agents for the reabsorption of lipids and fatty acids from the intestine. Hepatic and obstructive biliary diseases lead to abnormal metabolism of bile acids (BAs). 

Within a certain degree of hepatocellular damage, liver cell functions remain completely or widely intact at least, no impaired partial functions are yet detectable under clinical conditions. As liver damage progresses, however, numerous cellular functions become increasingly affected, so that clinically relevant disorders become evident. Thus impairment of the hepatic excretory capacity can be taken as a criterion of parenchymal damage. 

Even though the pathophysiology of hepatic changes during circulatory shock and in chronic liver congestion is very complex, two single mechanisms may be held jointly responsible for the impairment of metabolic and excretory liver functions ... 

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