Luminal CCK-releasing factors in the isolated vascularly perfused rat duodenojejunum

Abstract

The factors operating at the apical side of the endocrine cell releasing cholecystokinin (CCK) were investigated using the isolated vascularly perfused rat duodenojejunum. In the protease-free intestinal segment, a 30-min infusion of glucose (280 mM), oleic acid (100 mM), or triglycerides containing short- or long-chain fatty acids did not alter significantly the basal level of portal CCK-like immunoreactivity (CCK-LI), while octanoic acid (100 mM) produced a transient rise of plasma CCK-LI to approximately 250% of basal. Infusion of proteins (5% solutions of ovalbumin or casein) or of a mixture of all amino acids brought about a modest CCK secretion. In contrast, isocaloric amounts of an ovalbumin hydrolysate produced a sharp rise of portal CCK-LI to 530% of basal followed by a well-sustained plateau secretion (420% of basal) until the end of the infusion. An acid casein hydrolysate induced a slightly less pronounced CCK-LI release and was followed in decreasing order by meat, casein, and soybean peptones. Simultaneous infusion of trypsin with ovalbumin or casein hydrolysate reduced by approximately 60% the CCK release induced by peptone alone. This effect was reversed by coinfusion of soybean trypsin inhibitor (SBTI) with the trypsin-peptone mixture. Arterial infusion of tetrodotoxin (10(-6) M) or atropine (10(-5) M) had no significant effect on the trypsin-induced inhibition of peptone-mediated CCK-LI release. Administration of SBTI or camostate alone or in combination with trypsin did not alter basal CCK. Monitor peptide produced a dose-dependent transient rise of portal CCK-LI over the range from 2 to 12 micrograms.(ABSTRACT TRUNCATED AT 250 WORDS)

Co-requirement of Cyclic AMP- and Calcium-dependent Protein Kinases for Transcriptional Activation of Cholecystokinin Gene by Protein Hydrolysates

“…The peptide molecular weight distribution of peptones was previously determined and showed a majority (75%) of peptides with molecular size comprised between 120 and 1,200 Da and 5% of peptides with molecular size over 5,000 Da; the rest (20%) were free amino acids (14). Cell culture reagents were from Invitrogen (Cergy Pontoise,…”

“…peptones), which have been reported as a representative model of * The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S. the intestinal luminal dietary protein content (14), stimulated CCK gene transcription in the STC-1 enteroendocrine cell line, whereas intact proteins or free amino acids had no effect (15). The in vitro model allowed us to identify, in the CCK gene promoter, a DNA cis-element that was required for the transcriptional response to protein hydrolysates (16).…”

Suppressive Effect on Food Intake of a Potato Extract (Potein^®) Involving Cholecystokinin Release in Rats

“…[12][13][14] Some intact or partially digested proteins (peptone) exert strong stimulatory effects on CCK and other released satiety hormones and may therefore be applicable as functional food components to prevent over-eating. 15) Cuber et al 16) found that peptones, and not whole protein, carbohydrates or fats were strong stimulants of CCK release in the isolated rat duodenojejunum. Cordier-Bussat et al 11) have also proved that peptones directly stimulated CCK secretion in STC-1 cells.…”

Les lipides, protéines et glucides stimulent la sécrétion de cholécystokinine intestinale chez le porc

“…Parmi les acides aminés, le tryptophane et la phénylalanine sont les meilleurs sécrétagogues au moins chez le chien (Chang et Chey, 1983). Chez le rat, les protéines (Liddle et al, 1986) et les hydrolysats protéiques (Cuber et al, 1989e) …”

“…Les (Cuber et al, 1989a (Hopman ef al, 1985;Liddle et al, 1985;Miazza et al, 1985) et chez le chien (Fried et al, 1983;Shiratori et al, 1986) alors que seul un acide gras à chaîne courte (acide octanoïque) est capable d'induire une sécrétion transitoire de CCK chez le rat (Cuber et al, 1989e (Cuber et al, 1989c) et le gastric inhibitory polypeptide (Cuber et al, communication …”