On the possible use of the serum level of 7 alpha-hydroxycholesterol as a marker for increased activity of the cholesterol 7 alpha-hydroxylase in humans.
The possibility was investigated that the serum level of 7 alpha-hydroxycholesterol can be used as a marker for cholesterol 7 alpha-hydroxylase activity. Six patients with gallstone disease were found to have a mean level of 7 alpha-hydroxycholesterol in serum of 30 +/- 4 ng/ml (mean +/- SEM) as measured by isotope dilution-mass spectrometry, using deuterated 7 alpha-hydroxycholesterol as internal standard. After treatment with cholestyramine in a dose of 8 g twice daily for 2-3 weeks preoperatively, the serum level increased to 128 +/- 20 ng/ml (P less than 0.001). Eight other patients with gallstone disease had a mean level of 7 alpha-hydroxycholesterol in serum of 29 +/- 7 ng/ml. Treatment with chenodeoxycholic acid, 15 mg per kg body weight per day for 3-4 weeks before surgery, decreased the mean level to 20 +/- 7 ng/ml (P greater than 0.05). The activity of the cholesterol 7 alpha-hydroxylase in liver biopsies taken during operation was found to be 38 +/- 5 pmol/min per mg of protein in the group of patients treated with cholestyramine and 1.3 +/- 0.5 pmol/min per mg in the group of patients treated with chenodeoxycholic acid. Liver biopsies from a group of untreated patients (n = 13) had a mean cholesterol 7 alpha-hydroxylase activity of 7.6 +/- 1.5 pmol/min per mg.(ABSTRACT TRUNCATED AT 250 WORDS)
Björkhem
I
I
Department of Clinical Chemistry, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden.
Reihnér
E
E
Angelin
B
B
Ewerth
S
S
Akerlund
J E
JE
Einarsson
K
K
D000328:Adult; D000368:Aged; D002635:Chenodeoxycholic Acid / Q000627:therapeutic use; D002769:Cholelithiasis / Q000188:drug therapy / Q000378:metabolism*; D002790:Cholesterol 7-alpha-Hydroxylase / Q000378:metabolism*; D002792:Cholestyramine Resin / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006888:Hydroxycholesterols / Q000097:blood*; D007082:Ileum / Q000502:physiology / Q000601:surgery; D007408:Intestinal Absorption; D008099:Liver / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D013250:Steroid Hydroxylases / Q000378:metabolism*
D006888:Hydroxycholesterols; D002635:Chenodeoxycholic Acid; D002792:Cholestyramine Resin; C011724:cholest-5-en-3 beta,7 alpha-diol; D013250:Steroid Hydroxylases; D002790:Cholesterol 7-alpha-Hydroxylase