[Bioassay for plasma cholecystokinin bioactivity].
A sensitive and specific bioassay for the measurement of plasma cholecystokinin (CCK) is reported. CCK was extracted from plasma by SEP-PAK cartridges and the extracts were measured for CCK levels based on their ability to stimulate amylase release from dispersed rat pancreatic acini. Plasma CCK levels as low as 0.86 pmol/L (CCK-8 equivalent) were detectable. Gastrin in physiological concentration did not affect the bioassay. The amylase release stimulated by plasma extracts was abolished by Bt2-cGMP, a specific CCK receptor antagonist, indicating that there might be no secretin or VIP in plasma extracts. With this bioassay, fasting and postprandial plasma CCK levels of 11 normal volunteers were determined. The fasting level of CCK was 0.95 +/- 0.22 pmol/L (mean +/- SE). It increased to 2.98 +/- 0.67 pmol/L 15 minutes after feeding and remained significantly higher than the fasting level during a 60-minute period.
Sun
G
G
PUMC Hospital, Beijing.
D000328:Adult; D000681:Amylases / Q000378:metabolism; D001681:Biological Assay / Q000379:methods*; D002766:Cholecystokinin / Q000097:blood* / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000378:metabolism
D002766:Cholecystokinin; D000681:Amylases