Little information is available on the expression of cholecystokinin (CCK)
receptors in the human pancreas, especially in the developing pancreas. We
evaluated expression patterns for the CCK receptors in human pancreas at th
ree different ages: fetus, infant, and adult. Expressions of CCK-A and CCK-
B receptor messenger RNA (mRNA) were studied in human midtrimester fetus (1
4-15 weeks' gestation), infant (50 days old), and adult pancreas by reverse
transcription-polymerase chain reaction (RT-PCR) followed by Southern blot
analysis. Expression levels of mRNA for both receptors also were evaluated
by Northern blot analysis of adult pancreas. Northern blot analysis showed
a strong signal for CCK-B receptor mRNA in adult pancreas, but no detectab
le signal for CCK-A receptor mRNA. However, RT-PCR/Southern blotting showed
the presence of CCK-A receptor mRNA in adult pancreas. This was confirmed
by sequencing of the complementary DNA (cDNA). RT-PCR/Southern blot analysi
s also showed CCK-A and CCK-B receptor mRNA expression in fetal and infant
pancreas. These results show that the both CCK receptor types are expressed
in human pancreas at stages of early gestation, but there is predominant e
xpression of CCK-B receptor in adult pancreas.