Pharmacological and biochemical characterization of cholecystokinin/gastrin receptors in developing rat pancreas. Age-related expression of distinct receptor glycoforms.
Cholecystokinin/gastrin receptors in the pancreas of newborn (3-day-old) rats are of type A, as in control mature rats, revealed by pharmacological analysis of specific 125I-Bolton-Hunter-reagent-labelled [Thr34,Ahx37]cholecystokinin(31-39) (Ahx, aminohexanoic acid) binding. Also, by 1 day post-partum, pancreatic cholecystokinin receptors were shown to be coupled to guanine-nucleotide-binding regulatory (G) proteins. Scatchard analysis of 125I-Bolton-Hunter-reagent-labelled [Thr34,Ahx37]cholecystokinin(31-39) binding to pancreatic membranes from rats at different times after birth showed a slight increase in the binding capacity of cholecystokinin receptors between days 3 and 14 and a sixfold increase in 21-day-old rats, with no change in receptor affinity during development. SDS/PAGE analysis of pancreatic membranes affinity labelled with the photoactivable ligand 125I-[2-(p-azidosalicylamido)-1,3'-dithiopropionate]-labelled [Thr34,Ahx37]cholecystokinin-(31-39) identified cholecystokinin receptors of 100-135 kDa in 3-day-old rats, 96-130 kDa in 7-day-old rats, 90-125 kDa in 10-day-old rats and 85-100 kDa in 14-day-old and 21-day-old rats, as found in control adult rats. Endo-beta-N-acetylglucosaminidase F treatment yielded a core protein of 42 kDa in all developmental stages. These findings are consistent with an age-related postnatal expression of distinct glycoforms of pancreatic cholecystokinin receptors. Furthermore, it was observed that the period 2-3 weeks after birth, characterized by stabilization of the mass of the cholecystokinin receptor, precedes the dramatic increase in the receptor number.
Hadjiivanova
C
C
INSERM, Unité 151, Institut Louis Bugnard, CHU Rangueil, Toulouse, France.
Dufresne
M
M
Poirot
S
S
Sozzani
P
P
Vaysse
N
N
Moroder
L
L
Fourmy
D
D
D000345:Affinity Labels; D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002766:Cholecystokinin / Q000031:analogs & derivatives / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D019204:GTP-Binding Proteins / Q000502:physiology; D005755:Gastrins / Q000378:metabolism; D008297:Male; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase / Q000378:metabolism; D010179:Pancreas / Q000254:growth & development*; D010446:Peptide Fragments / Q000378:metabolism; D010777:Photochemistry; D051381:Rats; D011919:Rats, Inbred Strains; D011949:Receptors, Cholecystokinin / Q000378:metabolism*; D013388:Succinimides
D000345:Affinity Labels; D005755:Gastrins; D010446:Peptide Fragments; D011949:Receptors, Cholecystokinin; D013388:Succinimides; C072989:gastrin (2-17), desulfonated-; C072988:cholecystokinin (31-39), Thr(34)-Ahx(37)-; C022581:Bolton-Hunter reagent; D002766:Cholecystokinin; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D019204:GTP-Binding Proteins