Blockade of type A, but not type B, CCK receptors postpones satiety in rhesus monkeys

1993 ◽  
Vol 265 (3) ◽  
pp. R620-R624 ◽  
Author(s):  
T. H. Moran ◽  
P. J. Ameglio ◽  
H. J. Peyton ◽  
G. J. Schwartz ◽  
P. R. McHugh

The exogenous administration of the brain/gut peptide cholecystokinin (CCK) inhibits food intake in a variety of species, including subhuman primates and humans. To determine the role of endogenously released CCK in the control of food intake in rhesus monkeys, we examined the ability of the selective type A and type B CCK antagonists devazepide and L-365260 to affect total daily food intake and various meal patterns. Various doses of the antagonists were administered intragastrically 30 min before a daily 4-h feeding period. One-gram food pellets were delivered in response to lever pulls, and intake was computer monitored. Intragastric administration of the type A CCK receptor antagonist devazepide (10-320 micrograms/kg) significantly increased food intake in a dose-related fashion. The threshold for increasing intake was 32 micrograms/kg, and a maximal effect was obtained at a dose of 100 micrograms/kg that increased total 4-h food intake by 47%. The effect of devazepide on food intake was mediated by significant increases in the size and duration of the initial meal, lengthening of the subsequent intermeal interval, and a decrease in the satiety ratio (intermeal interval/1st meal size). In contrast, intragastric administration of the type B CCK receptor antagonist L-365260 (3.2-320 micrograms/kg) did not significantly affect total food intake or any of the meal parameters. These data demonstrate that endogenously released CCK acting through type A CCK receptors plays a role in regulating food intake in rhesus monkeys.

1992 ◽  
Vol 262 (1) ◽  
pp. R46-R50 ◽  
Author(s):  
T. H. Moran ◽  
P. J. Ameglio ◽  
G. J. Schwartz ◽  
P. R. McHugh

Recent work has suggested a role for an endogenous release of cholecystokinin (CCK) acting at either type A or type B CCK receptors in the control of food intake. In an effort to investigate whether the mechanisms by which exogenously administered and endogenously released CCK inhibits food intake are similar and depend upon interactions with either type A or type B CCK receptors, we examined in rats the ability of the type A (L 364718) and type B (L 365260) CCK receptor antagonists to 1) block the inhibition of glucose consumption produced by an intraperitoneal injection of 4 micrograms/kg of CCK and 2) increase glucose consumption in the absence of exogenous CCK after a 6-h daytime deprivation. Increasing dosages (10-100 micrograms/kg) of the type A CCK antagonist resulted in a dose-related blockade of the inhibition of intake produced by CCK, and the 100 micrograms/kg dose of the A antagonist significantly increased glucose intake above baseline levels. In contrast, no dose (10-1,000 micrograms/kg) of the B antagonist blocked the inhibitory action of exogenous CCK at any time point. In the absence of exogenous CCK, the 32 and 100 micrograms/kg doses of L 364718 increased intake above baseline levels. No dose (3.2-320 micrograms/kg) of the type B antagonist, L 365260, affected intake in this paradigm. These results suggest that the mediation of the feeding-inhibitory effects of exogenous and endogenous CCK are similar and depend upon activation of type A CCK receptors.


1997 ◽  
Vol 272 (1) ◽  
pp. R334-R340 ◽  
Author(s):  
A. Rodriguez-Sinovas ◽  
E. Fernandez ◽  
X. Manteca ◽  
A. G. Fernandez ◽  
E. Gonalons

The aim of this work was to study the involvement of cholecystokinin (CCK) in the control of food intake in chickens. The following aspects were studied: 1) the effects of intravenous and intracerebroventricular sulfated octapeptide of CCK (CCK-8s) on voluntary food intake; 2) the effects of two CCK-receptor antagonists. L-365,260 and L-364,718, on food intake; and 3) the ability of such drugs to block the effects of CCK-8s on food intake in the chicken. Intravenous and intracerebroventricular CCK-8s caused a decrease in food intake. Intraperitoneal L-365,260, a CCK-receptor antagonist with low affinity for the two CCK receptors described in the chicken, increases food intake. Intracerebroventricular L-364,718, a drug that has high affinity for the chicken central CCK-receptor type, increased food intake. The effect of intravenous CCK-8s on food intake was not blocked by L-364,718 or L-365,260, whereas that of intracerebroventricular CCK-8s was blocked by intracerebroventricular L-364,718. It is concluded that central endogenous CCK plays a role in the control of food intake, which is dependent on central CCK-receptor type; nevertheless, peripheral CCK also decreases food intake acting on the peripheral CCK-receptor type. The fact that intracerebroventricular L-364,718 is able to increase food intake is related to its high affinity for the central CCK-receptor type of this species. Finally, three different speculations that might explain the fact that intraperitoneal L-365,260 increases food intake are discussed.


1992 ◽  
Vol 263 (6) ◽  
pp. R1354-R1358 ◽  
Author(s):  
R. D. Reidelberger

The hypothesis that peripherally administered cholecystokinin C-terminal octapeptide (CCK-8) and endogenous CCK act by the same abdominal vagal mechanism to produce satiety was tested by injecting rats with CCK-8 or the type A CCK receptor antagonist MK-329 after they had received bilateral subdiaphragmatic vagotomies. CCK-8 (8 nmol/kg ip) inhibited 1-h food intake by 60%; vagotomy and MK-329 (0.5 mg/kg sc) each completely blocked this effect. In contrast, vagotomy did not alter the stimulatory effect of MK-329 (0.5 mg/kg sc) on feeding; 3-h cumulative intake in control and vagotomized animals was increased by 25 and 34%, respectively. These results suggest that satiety is mediated in part by an endogenous CCK action that is independent of abdominal vagal innervation.


1990 ◽  
Vol 258 (1) ◽  
pp. E40-E45 ◽  
Author(s):  
J. Garlicki ◽  
P. K. Konturek ◽  
J. Majka ◽  
N. Kwiecien ◽  
S. J. Konturek

This study was designed to determine the specificity and physiological nature of short-term satiety effects of cholecystokinin (CCK) in rats with intact and transected vagal nerves. Rats with-the gastric fistulas, closed or open, were used for normal feeding or sham feeding of liquid meal offered for 30 min. CCK-8 (0.5-10 nmol/kg) injected intraperitoneally (ip) 15 min before feeding inhibited food intake dose dependently in both normal-fed and sham-fed rats at a minimal inhibitory dose of 1 nmol/kg. CCK-8 at the same doses caused a potent stimulation of pancreatic protein secretion, reaching maximum at a dose of approximately 0.5 nmol/kg. Pretreatment with a potent CCK receptor antagonist, L-364,718 (2.5 mg/kg ip), increased food intake during normal feeding (but not sham feeding) and almost completely blocked the satiety and pancreatic stimulatory effects of CCK. When feeding was preceded by intragastric administration of proteinase inhibitor (Foy-305, 200 mg/kg), food preload, or diversion of bile-pancreatic secretion to the exterior, there was a significant increase in the plasma level of CCK and an inhibition of food intake by about 36, 78, and 25%, respectively. Pretreatment with L-364,718 completely abolished this inhibition by Foy-305 and bile-pancreatic diversion and reduced that caused by food preload. Among other gut peptides given ip (10 nmol/kg) only bombesin reduced food intake, whereas gastrin, secretin, gastric inhibitory polypeptide (GIP), pancreatic polypeptide (PP), and peptide YY (PYY) were ineffective.(ABSTRACT TRUNCATED AT 250 WORDS)


1993 ◽  
Vol 265 (2) ◽  
pp. R371-R375 ◽  
Author(s):  
T. H. Moran ◽  
P. J. Ameglio ◽  
G. J. Schwartz ◽  
H. J. Peyton ◽  
P. R. McHugh

A role for the brain/gut peptide cholecystokinin (CCK) in the control of gastric emptying has been proposed. In the present studies, we have used a potent type A CCK-receptor antagonist (devazepide) to examine the quantitative contribution of endogenously released CCK in the control of liquid gastric emptying of 100 ml lipid, protein, and carbohydrate test loads in rhesus monkeys. Emptying was studied in conscious monkeys equipped with chronic indwelling gastric cannulas. Prior intragastric administration of devazepide (1.0-320 micrograms/kg) differentially affected the 10-min emptying of glucose (0.125/ml), peptone (4.5%), and Intralipid (4.5%). Glucose emptying was not affected by any dose of the CCK antagonist. The emptying of peptone was accelerated by doses of 10 micrograms/kg or higher. This effect, however, was only partial and plateaued at a dose of 100 micrograms/kg. The gastric emptying of Intralipid was accelerated at a dose of 32 micrograms/kg, and the inhibitory effect of the Intralipid was completely eliminated at a dose of 320 micrograms/kg. At this dose of devazepide, the Intralipid test meal emptied from the stomach at the same rate as physiological saline. These data demonstrate that in rhesus monkeys endogenously released CCK 1) does not play a role in the control of glucose emptying, 2) is a partial mediator of the inhibitory action of peptone on gastric emptying, and 3) is the primary inhibitory mediator in the control of the gastric emptying of Intralipid.


2020 ◽  
Vol 4 (s1) ◽  
pp. 93-94
Author(s):  
Martha Gay ◽  
Anita Safronenka ◽  
Hong Cao ◽  
Robin Tucker ◽  
Narayan Shivapurkar ◽  
...  

OBJECTIVES/GOALS: NASH increases the risk of cirrhosis and liver cancer. High-fat diets increase CCK levels and CCK receptors have been identified on fibroblasts and immune cells. We hypothesized that CCK receptor blockade could prevent NASH by altering the hepatic microenvironment and macrophage activation. METHODS/STUDY POPULATION: Female mice were fed a Choline Deficient Ethionine supplemented (CDE) saturated fat diet or control high-fat diet for 18 weeks. Mice in each group were treated with a CCK receptor antagonist, proglumide (0.1 mg/ml) in the drinking water or regular water. Resected livers were stained for H&E for features of NASH and F4/80 for macrophages analysis. Liver RNA was evaluated for the expression of cytokines and chemokines using an 84-gene Profiler array (Qiagen). Oxidative stress was analyzed by qRT-PCR for heat shock proteins (HSPs) 27, 60, 70 and 90 and for glutathione by a fluorometric assay. Differences in CDE fed and CDE/proglumide-treated mouse livers were evaluated. RESULTS/ANTICIPATED RESULTS: Livers from mice on the CDE diet displayed histologic features of NASH that were prevented by proglumide. Cytokines and chemokines expression, especially CCL20 and CCL2, were increased in the CDE fed mice and these levels were reduced greater than 20-fold with proglumide. Infiltration of F4/80+ macrophages was markedly increased in the CDE livers and these were reduced by > 50% (p < 0.0001) with proglumide. RNA expression of HSP70 (p = 0.006) and HSP27 (p = 0.011) were reduced with proglumide. Hepatic glutathione concentration more than doubled in the CDE/proglumide treated mice compared to CDE mice. CCK-B receptor expression increased in the CDE-fed mouse livers compared to controls. DISCUSSION/SIGNIFICANCE OF IMPACT: CCK receptor blockade decreases NASH by reducing hepatic macrophages, oxidative stress, and blocking inflammatory cytokines and chemokines. This data supports our novel hypothesis that CCK receptors play a role in NASH and proglumide may provide an innovative treatment for this condition.


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