Am J Physiol Endocrinol Metab
June 2011
Ghrelin, known to stimulate adipogenesis, displays an endogenous secretory rhythmicity closely related to meal patterns. Therefore, a chronic imposed feeding schedule might induce modified ghrelin levels and consequently adiposity. Growing Wistar rats were schedule-fed by imposing a particular fixed feeding schedule of 3 meals/day without caloric restriction compared with total daily control intake.
View Article and Find Full Text PDFCholecystokinin, produced in the proximal small intestine, is a short acting satiating peptide hormone. CCK-10, before and after mono-iodination, was previously coupled to 10kDa polyethylene glycol (PEG). The formed conjugates PEG10kDa-CCK-10 and PEG10kDa-[(127)I]-CCK-10 show after i.
View Article and Find Full Text PDFSimmondsin, a cyanoglycoside from jojoba meal, reduces food intake after oral administration. To diagnose if it acts by inducing satiation or by creating abnormal physiological effects, an observational study was undertaken to investigate the effects of simmondsin on feeding and other behaviors. Particular attention was paid to the behavioral sequence associated with satiety (BSS).
View Article and Find Full Text PDFCholecystokinin (CCK) is known to have a short biological half-life. In order to prolong the half-life and create a new investigative tool, we previously PEGylated the peptide, yielding PEG-CCK(9), and demonstrated that it had a dose-dependent prolonged anorectic effect. The aim of this study was to investigate whether PEG-CCK(9) reduces food intake by inducing satiation or by abnormal physiological effects, such as pain, malaise, or nausea.
View Article and Find Full Text PDFCholecystokinin (CCK) is a short acting satiating peptide hormone produced in the proximal small intestine. Daily CCK injection in rats initially inhibits food intake, but after several days, food intake is no longer affected, suggesting development of tolerance. Previously, we covalently coupled CCK to a 10kDa polyethylene glycol (mPEG-OH) and showed that this conjugate, PEG-CCK(9), produced a significantly longer anorectic effect than unmodified CCK(9).
View Article and Find Full Text PDFBackground And Purpose: The physiological involvement of endogenous cholecystokinin (CCK) in the termination of feeding has been challenged by evidence of aversive effects of exogenous CCK8. We previously prolonged the anorectic effect of CCK by conjugation to polyethylene glycol (PEGylation) to produce PEG-CCK9. In this study, we investigated the ability of different doses of PEG-CCK9 to induce conditioned taste aversion (CTA) and satiety and identified the receptors involved in CTA induction.
View Article and Find Full Text PDFBackground And Purpose: Acute intraperitoneal (i.p.) administration of cholecystokinin (CCK) is known to induce a significant, but short-lasting, reduction in food intake, followed by recovery within hours.
View Article and Find Full Text PDFThe anorectic compound CCK-9 was coupled to polyethylene glycol 5 kDa, 10 kDa, 20 kDa and 30 kDa, under different reaction conditions. Conjugates were purified by HPLC and characterized by MALDI-TOF MS. A 96% PEGylation yield was obtained in buffer pH 7.
View Article and Find Full Text PDFBiosens Bioelectron
December 2004
Hormone-receptor interactions occur following three-dimensional diffusion of the ligand to the membrane-embedded receptor. However, prior hydrophobization of the ligand might restrict its movement to two dimensions along the membrane surface, and the biological response might therefore be modulated. This idea was tested using the C-terminal nonapeptide, CCK9, of the satiating hormone, cholecystokinin (CCK).
View Article and Find Full Text PDFA mixture of lysophosphatidylcholine (LPC) and phosphatidylcholine (PC) has been isolated by column chromatography from a jojoba meal (Simmondsia chinensis) extract. The molecular species of both classes could be separated and isolated by C18 reversed phase HPLC. The two major compounds were identified by 1D and 2D (1)H and (13)C NMR, by MS, and by GC-MS as 1-oleoyl-3-lysophosphatidylcholine and 1,2-dioleoyl-3-phosphatidylcholine.
View Article and Find Full Text PDFSimmondsin, a glycoside from jojoba meal, decreases food intake after oral administration. The present experiments are designed to clarify the mechanism of simmondsin's anorectic activity. The meal pattern analysis shows that simmondsin supplementation at different doses results in a dose-dependent food intake reduction, which is more pronounced after prior simmondsin experience.
View Article and Find Full Text PDFJ Agric Food Chem
February 2003
Jojoba seed meal shows appetite-suppressing activity due to the presence of simmondsin. This pharmacological activity disappears with treatment of the meal with sodium hydroxide. To elucidate this mechanism of inactivation, the reaction of simmondsin in 1 N NaOH at 20 degrees C was monitored as a function of time.
View Article and Find Full Text PDFSeparate methods for the analyses of soluble carbohydrates in different plants and simmondsins in jojoba seed meal are described. A reliable gas chromatographic procedure for the simultaneous quantification of D-pinitol, myo-inositoL sucrose, 5-alpha-D-galactopyranosyl-D-pinitol. 2-alpha-D-galactopyranosyl-D-pinitol, simmondsin, 4-demethylsimmondsin, 5-demethylsimmondsin and 4,5-didemethylsimmondsin as trimethylsilyl derivatives in jojoba seed meal has been developed.
View Article and Find Full Text PDFThe isolation and identification of two pinitol alpha-D-galactosides from jojoba meal are described. The products were isolated by a combination of preparative HPLC on silica gel and TLC on amino silica gel and were identified by MS, NMR spectroscopy, and chemical derivatization as 5-O-(alpha-D-galactopyranosyl)-3-O-methyl-D-chiro-inositol or 5-alpha-D-galactopyranosyl-D-pinitol and 2-O-(alpha-D-galactopyranosyl)-3-O-methyl-D-chiro-inositol or 2-alpha-D-galactopyranosyl-D-pinitol. The same preparative HPLC method on silica gel allowed a new simmondsin derivative to be isolated and identified as 4,5-didemethyl-4-O-alpha-D-glucopyranosylsimmondsin mainly by NMR spectroscopy and high-resolution mass spectrometry.
View Article and Find Full Text PDFTo look for possible developmental effects in the offspring of jojoba meal-treated Wistar rats, and to distinguish between the effects of reduced food intake and the specific developmental effects of jojoba meal itself, mated female rats were divided into three groups of 20 rats. They received during gestation: (a) normal rodent food (control group); (b) normal rodent food supplemented with 3% defatted jojoba meal (jojoba group); or (c) normal rodent food pair-fed with the jojoba group (pair-fed group). The jojoba meal group showed approximately 30% inhibition of food intake.
View Article and Find Full Text PDFSupplementation of feed with jojoba meal, as a means for autonomous feed restriction, was successful in depressing feed intake and controlling body weight of broiler breeder pullets to the extent recommended by the breeder company. However, these broiler breeders never produced eggs. At the level of ovary, normal follicle development and maturation did occur.
View Article and Find Full Text PDFJ Agric Food Chem
September 2000
A capillary gas chromatographic method was developed for the simultaneous determination of simmondsins and simmondsin ferulates in jojoba meal, in detoxified jojoba meal, in jojoba meal extracts, and in animal food mixtures.
View Article and Find Full Text PDFSimmondsin, 2-(cyanomethylene)-3 hydroxy 4,5 dimethoxy cyclohexyl beta-D-glucoside, from jojoba meal reduces food intake in rats. We investigated the mechanism of action simmondsin, by studying the effects of fasting or of vagotomy on the food intake reduction. The food intake reduction was significantly less in fasted rats than in non-fasted rats.
View Article and Find Full Text PDF1. This study was undertaken to investigate whether jojoba meal can be used as a food supplement during the laying period of chickens. 2.
View Article and Find Full Text PDFIncorporation of 2.5 g/kg of the anorexigen, simmondsin, in the diet resulted in food intake reduction in both lean and obese Zucker rats; however, the obese rats were much more sensitive to the food intake-reducing activity of simmondsin. In both obese and lean simmondsin-treated Zucker rats, growth was slower than in control rats, but was the same as that in pair-fed animals.
View Article and Find Full Text PDFIn this study, we investigated the analogies between the physiological effects of simmondsin, a satiety-inducing glycoside extracted from jojoba seeds, and the gastro-intestinal satiation peptide, cholecystokinin. The effects of intraperitoneal injection of the biological active CCK-octapeptide on the pancreas, interscapular brown adipose tissue, growth performance and energy metabolism in normal-fed, severely food intake-restricted (50 % of normal food intake) or moderately food intake-restricted (65 % of normal food intake) growing rats were compared to the effects of 0.25 % simmondsin mixed in the food, inducing moderate food intake reduction (65 % of normal) in rats.
View Article and Find Full Text PDFThe effects on food intake, growth and reproductive performance parameters of defatted jojoba meal and pure simmondsin, an extract from jojoba meal, were compared in female Wistar rats. Rats fed 0.15% simmondsin or 3% defatted jojoba meal (equivalent to 0.
View Article and Find Full Text PDFThe effect of a long-term 50% food restriction on plasma thyroid hormone levels was studied in adult male rats, which received their reduced daily amount of food either as one meal or 5 different meals. Compared to controls, a long-term food restriction reduced total 24 h-mean plasma T4, T3 and TSH concentrations. The total T4 level was more reduced in rats fed their reduced ration in one meal than in rats given food in several meals.
View Article and Find Full Text PDFGen Comp Endocrinol
December 1995
The effects of a long term partial food restriction were studied in chickens and rats. In chickens the treatment resulted in increased plasma T4 levels while T4 levels in rats remained unchanged. Plasma T3 decreased in both species.
View Article and Find Full Text PDFSimmondsin, a glycoside extracted from jojoba meal (Simmondsia chinensis), causes a reduction in food intake after oral administration. To investigate the mechanism by which simmondsin reduces food intake, fasted and free-feeding rats were given simmondsin-supplemented food and simultaneously injected with devazepide, a specific antagonist of peripheral-type cholecystokinin receptors (CCKA receptors). In free-feeding rats, supplementation of food with 0.
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