Linked Life Data

2463851

Source:http://linkedlifedata.com/resource/pubmed/id/2463851

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1989-3-9
pubmed:abstractText
When pancreatic acini are incubated with increasing concentrations of cholecystokinin octapeptide (CCK-8) the dose-response curve for stimulation of enzyme secretion increases, reaches a maximum and then decreases. The upstroke of the dose-response curve reflects occupation of high-affinity, stimulatory CCK receptors (Kd 69 pM), whereas the downstroke of the dose-response curve reflects occupation of low-affinity inhibitory CCK receptors (Kd 10 nM). In the present study, we used dispersed acini from rat pancreas to examine the effects of CCK-JMV-180, an analogue of the C-terminal heptapeptide of CCK (CCK-7) having the structure BOC-Tyr(SO3) Ahx-Gly-Trp-Ahx-Asp2 phenylethyl ester. CCK-JMV-180 inhibited binding of 125I-labelled CCK-8 to pancreatic acini. Computer analysis of the dose-inhibition curve indicated that CCK-JMV-180 interacted with both classes of CCK receptor and had a Kd of 2.2 nM for high-affinity CCK receptors and a Kd of 19 nM for low-affinity CCK receptors. Occupation of high-affinity CCK receptors by CCK-JMV-180 caused a 14-fold increase in amylase secretion, the same increase caused by occupation of these high-affinity receptors by CCK-7 or CCK-8. Occupation of low-affinity CCK receptors by CCK-JMV-180 did not alter amylase secretion, in contrast to occupation of these low-affinity receptors by CCK-7 or CCK-8, each of which caused inhibition of amylase secretion. Furthermore, occupation of the low-affinity CCK receptors by CCK-JMV-180 reversed the inhibition of amylase secretion caused by a supramaximal concentration of CCK-8. The present results indicate that CCK-JMV-180 interacts with high-affinity CCK receptors and with low-affinity CCK receptors, and has a functionally distinct action at each class of receptor: CCK-JMV-180 is an agonist at the high-affinity receptors and a competitive antagonist at the low-affinity receptors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
1010
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
145-50
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
CCK-JMV-180: a peptide that distinguishes high-affinity cholecystokinin receptors from low-affinity cholecystokinin receptors.
pubmed:affiliation
Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892.
pubmed:publicationType
Journal Article