Evaluation of Intestinal Absorption of Dietary Halocynthiaxanthin, a Carotenoid from the Sea Squirt Halocynthia roretzi

Halocynthiaxanthin is an acetylenic carotenoid mainly found in Halocynthia roretzi. To date, several bioactivities of halocynthiaxanthin have been reported, but its mechanism of digestion and absorption in mammals has not been studied yet. In this study, we evaluated the intestinal absorption of halocynthiaxanthin in mice. The halocynthiaxanthin-rich fraction was prepared from the tunicate Halocynthia roretzi. Mice were orally administered the fraction at a dose of 5 mg/kg body weight. The halocynthiaxanthin levels in the plasma, liver, and small intestine, were quantified using HPLC-PDA, 1, 3, 6, and 9 h after ingestion. The halocynthiaxanthin-rich fraction mainly consisted of the all-trans form and a small amount of cis forms. These three isomers were detected in the plasma of mice 3 h after ingestion. Time-course changes after the ingestion of this fraction were found, with cis isomers being more abundant than the all-trans isomer in the mouse plasma and liver. In the small intestine, however, the all-trans isomer was primarily detected. The possibility that cis isomers might be absorbed rapidly from the small intestine cannot be denied, but our results suggest that dietary all-trans-halocynthiaxanthin might be isomerized to the cis isomer after intestinal absorption.

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Angiotensin-converting enzyme preferentially hydrolyzes trans isomer of proline-containing substrate

Journal of Applied Physiology ◽

10.1152/jappl.1993.75.4.1519 ◽

1993 ◽

Vol 75 (4) ◽

pp. 1519-1524 ◽

Cited By ~ 7

Author(s):

M. P. Merker ◽

C. A. Dawson ◽

R. D. Bongard ◽

D. L. Roerig ◽

S. T. Haworth ◽

...

Keyword(s):

Angiotensin Converting Enzyme ◽

Trans Isomer ◽

Rate Constant ◽

Time Course ◽

Enzyme Concentration ◽

Hydrolysis Rate ◽

Converting Enzyme ◽

Trans Form ◽

Hydrolysis Of

An analysis of the hydrolysis kinetics of the synthetic angiotensin-converting enzyme (ACE) substrate benzoyl-phenylalanyl-alanyl-proline (BPAP) in the intact lung suggested that 12–15% of the BPAP was in a form that could not be hydrolyzed by ACE in the time course of a single pass through the lungs [C. A. Dawson et al. Am. J. Physiol. 257 (Heart Circ. Physiol. 26): H853-H865, 1989]. BPAP has been found to exist as a mixture of cis and trans isomers in a ratio of approximately 14:86 in aqueous solution at equilibrium. Thus, one possible explanation for the incomplete hydrolysis of BPAP on passage through the intact lung is that the trans form is the preferred substrate for ACE. To examine this hypothesis, we measured BPAP hydrolysis by ACE in vitro over a range of ACE concentrations and in the presence and absence of the peptidyl-prolyl cis-trans isomerase cyclophilin. In the presence of a sufficient concentration of ACE and in the absence of cyclophilin, hydrolysis of [3H]BPAP by ACE followed biexponential progress curves, consistent with the hypothesis that the rate of hydrolysis of the majority (approximately 87%) of the substrate is proportional to ACE concentration, whereas the hydrolysis rate of the remaining substrate fraction is independent of enzyme concentration. The addition of cyclophilin resulted in an increase in the ACE-independent rate constant, an effect that was reversed by the cyclophilin inhibitor cyclosporin A. These results suggest that the enzyme-independent rate constant represents the rate of cis-trans isomerization and that the enzyme-dependent rate constant represents the hydrolysis of the trans isomer.(ABSTRACT TRUNCATED AT 250 WORDS)

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Time course changes of fibrous structure within connective tissue. Why do "wrinkles" or "sags" develop with age?

Nishi Nihon Hifuka ◽

10.2336/nishinihonhifu.51.1093 ◽

1989 ◽

Vol 51 (6) ◽

pp. 1093-1100 ◽

Cited By ~ 1

Author(s):

SHUHEI IMAYAMA

Keyword(s):

Connective Tissue ◽

Time Course ◽

Fibrous Structure ◽

Course Changes

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Histopathological study of time course changes in inter-renal aortic banding-induced left ventricular hypertrophy of mice

International Journal of Experimental Pathology ◽

10.1111/j.1365-2613.2006.00514.x ◽

2006 ◽

Vol 88 (1) ◽

pp. 31-38 ◽

Cited By ~ 9

Author(s):

Hiroyuki Higashiyama ◽

Masaki Sugai ◽

Hirotaka Inoue ◽

Kaori Mizuyachi ◽

Hiroshi Kushida ◽

...

Keyword(s):

Left Ventricular Hypertrophy ◽

Ventricular Hypertrophy ◽

Time Course ◽

Left Ventricular ◽

Histopathological Study ◽

Aortic Banding ◽

Course Changes

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Effects of acute and chronic treatment with glucocorticoids on the intestinal absorption of calcium and phosphate and on plasma 1,25-dihydroxyvitamin D levels in pigs

Clinical Science ◽

10.1042/cs0690553 ◽

1985 ◽

Vol 69 (5) ◽

pp. 553-559 ◽

Cited By ~ 8

Author(s):

John Fox ◽

Richardus Ross ◽

Anthony D. Care

Keyword(s):

Intestinal Absorption ◽

Plasma Levels ◽

Time Course ◽

Chronic Treatment ◽

Intestinal Loop ◽

Phosphate Absorption ◽

Dihydroxyvitamin D ◽

1,25 Dihydroxyvitamin D ◽

Young Pigs ◽

Proximal Small Intestine

1. We have used young pigs, each prepared surgically with a Thiry-Vella loop of proximal small intestine, to study the time course of changes in the intestinal absorption of calcium, phosphate, sodium, glucose and water and on the plasma levels of 1,25-dihydroxyvitamin D after treatment of the animals with glucocorticoids. 2. Perfusion of the intestinal loop for 6 h with a solution containing hydrocortisone or betamethasone was without effect on the absorption of calcium or phosphate. 3. The oral administration of betamethasone stimulated the absorption of calcium and phosphate by 15–20% for 2–3 days before the trend was reversed and absorption was progressively reduced. 4. Chronic treatment with betamethasone inhibited only the active component of calcium and phosphate absorption. 5. Treatment with betamethasone was associated with a sustained 25–50% increase, to a maximum by 2 days, in the absorption of sodium, glucose and water. 6. Plasma levels of 1,25-dihydroxyvitamin D were reduced within 2 days of the start of treatment and reached a minimum (40–50% decrease) in 4–6 days. 7. We conclude that the initial stimulation of calcium and phosphate absorption is caused by the increased absorption of water. The long-term decrease in absorption may not be caused solely by the decreased circulating levels of 1,25-dihydroxyvitamin D since absorption continued to fall for several weeks after 1,25-dihydroxyvitamin D levels had reached a minimum.

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Absorption Properties of Luteolin and Apigenin in Genkwa Flos Using In Situ Single-Pass Intestinal Perfusion System in the Rat

The American Journal of Chinese Medicine ◽

10.1142/s0192415x1750094x ◽

2017 ◽

Vol 45 (08) ◽

pp. 1745-1759 ◽

Cited By ~ 6

Author(s):

Xin He ◽

Zi-Jing Song ◽

Cui-Ping Jiang ◽

Chun-Feng Zhang

Keyword(s):

Small Intestine ◽

Intestinal Absorption ◽

Rat Model ◽

Clinical Effectiveness ◽

Intestinal Perfusion ◽

Flower Bud ◽

Transport Pathway ◽

Absorption Enhancers ◽

Single Pass

The flower bud of Daphne genkwa (Genkwa Flos) is a commonly used herbal medicine in Asian countries. Luteolin and apigenin are two recognized active flavonoids in Genkwa Flos. The aim of this study was to investigate the intestinal absorption mechanisms of Genkwa Flos flavonoids using in situ single-pass intestinal perfusion rat model. Using HPLC, we determined its major effective flavonoids luteolin, apigenin, as well as, hydroxygenkwanin and genkwanin in biological samples. The intestinal absorption mechanisms of the total flavonoids in Genkwa Flos (TFG) were investigated using in situ single-pass intestinal perfusion rat model. Comparing the TFG absorption rate in different intestinal segments, data showed that the small intestine absorption was significantly higher than that of the colon ([Formula: see text]). Compared with duodenum and ileum, the jejunum was the best small intestinal site for TFG absorption. The high TFG concentration (61.48[Formula: see text][Formula: see text]g/ml) yielded the highest permeability ([Formula: see text]). Subsequently, three membrane protein inhibitors (verapamil, pantoprazole and probenecid) were used to explore the TFG absorption pathways. Data showed probenecid, a multidrug resistance protein (or MRP) inhibitor, effectively enhanced the TFG absorption ([Formula: see text]). Furthermore, by comparing commonly used natural absorption enhancers on TFG, it was observed that camphor was the most effective. In Situ single-pass intestinal perfusion experiment shows that TFG absorption is much higher in the small intestine than in the colon, and the TFG is absorbed mainly via an active transport pathway with MRP-mediated efflux mechanism. Camphor obviously enhanced the TFG absorption, and this could be an effective TFG formulation preparation method to increase clinical effectiveness after Genkwa Flos administration. Our study elucidated the TFG absorption mechanisms, and provided new information for its formulation preparation.

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Reaction of cis- and trans-Dichlorotetra(Dimethylsulfoxide)Ruthenium(II) With the Antiviral Drug Acyclovir

Metal-Based Drugs ◽

10.1155/mbd.2000.325 ◽

2000 ◽

Vol 7 (6) ◽

pp. 325-334 ◽

Cited By ~ 1

Author(s):

Aglaia Koutsodimou ◽

Giovanni Natile

Keyword(s):

Trans Isomer ◽

Early Stage ◽

Antiviral Drug ◽

Metallic Substrate ◽

Purine Base ◽

Coordination Environment ◽

Molar Ratios ◽

Discrete Amount ◽

Cis And Trans ◽

Cis Isomer

NMR was used to investigate the reaction of cis- and trans-[RuCl2(DMSO)4] with the antiviral drug acyclovir, a guanine derivative containing the acyclic (2-hydroxo) ethoxymethyl pendant linked to N(9). Studies were performed in aqueous solutions at ambient temperature and at 37 °C, and at various molar ratios. Both isomers yielded two compounds, a monoadduct and a bisadduct, the relative yields being dependent upon the metal to ligand concentration ratios. The products derived from the two Ru isomers displayed identical NMR spectra, suggesting that they have the same coordination environment, however the rate of formation of the monoadduct was higher in the case of the trans isomer than in the case of the cis isomer, while the rate of conversion of the monoadduct into the bisadduct appeared to be similar in both cases. As a consequence in the case of the trans isomer there is accumulation of monoadduct in the early stage of the reaction, whose concentration afterwards decreases with the progress of the reaction. As for platinum, also for ruthenium the preferred binding site is N(7) of the purine base, however, in the case of ruthenium a discrete amount of bisadduct is formed even in the presence of an excess of metallic substrate with respect to the acyclovir ligand; under similar conditions a platinum substrate would have given, nearly exclusively, the monoadduct.

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Time course changes of vasopressin-induced enlargement of the rat intrastrial space and the effects of a vasopressin type 2 antagonist

Acta Oto-Laryngologica ◽

10.1080/00016480802419115 ◽

2009 ◽

Vol 129 (7) ◽

pp. 709-715 ◽

Cited By ~ 12

Author(s):

Masahiko Nishimura ◽

Akinobu Kakigi ◽

Taizo Takeda ◽

Teruhiko Okada ◽

Katsumi Doi

Keyword(s):

Time Course ◽

Course Changes

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Effects of Clostridium perfringens Beta-Toxin on the Rabbit Small Intestine and Colon

Infection and Immunity ◽

10.1128/iai.00547-08 ◽

2008 ◽

Vol 76 (10) ◽

pp. 4396-4404 ◽

Cited By ~ 54

Author(s):

Jorge E. Vidal ◽

Bruce A. McClane ◽

Juliann Saputo ◽

Jaquelyn Parker ◽

Francisco A. Uzal

Keyword(s):

Small Intestine ◽

Clostridium Perfringens ◽

Time Course ◽

Defense Mechanism ◽

Intestinal Damage ◽

Loop Model ◽

Type B ◽

Ileal Loop ◽

Type C ◽

Beta Toxin

ABSTRACT Clostridium perfringens type B and type C isolates, which produce beta-toxin (CPB), cause fatal diseases originating in the intestines of humans or livestock. Our previous studies demonstrated that CPB is necessary for type C isolate CN3685 to cause bloody necrotic enteritis in a rabbit ileal loop model and also showed that purified CPB, in the presence of trypsin inhibitor (TI), can reproduce type C pathology in rabbit ileal loops. We report here a more complete characterization of the effects of purified CPB in the rabbit small and large intestines. One microgram of purified CPB, in the presence of TI, was found to be sufficient to cause significant accumulation of hemorrhagic luminal fluid in duodenal, jejunal, or ileal loops treated for 6 h with purified CPB, while no damage was observed in corresponding loops receiving CPB (no TI) or TI alone. In contrast to the CPB sensitivity of the small intestine, the colon was not affected by 6 h of treatment with even 90 μg of purified CPB whether or not TI was present. Time course studies showed that purified CPB begins to induce small intestinal damage within 1 h, at which time the duodenum is less damaged than the jejunum or ileum. These observations help to explain why type B and C infections primarily involve the small intestine, establish CPB as a very potent and fast-acting toxin in the small intestines, and confirm a key role for intestinal trypsin as an innate intestinal defense mechanism against CPB-producing C. perfringens isolates.

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Cerebral oxygenation changes in response to motor stimulation

Journal of Applied Physiology ◽

10.1152/jappl.1996.81.3.1174 ◽

1996 ◽

Vol 81 (3) ◽

pp. 1174-1183 ◽

Cited By ~ 165

Author(s):

H. Obrig ◽

C. Hirth ◽

J. G. Junge-Hulsing ◽

C. Doge ◽

T. Wolf ◽

...

Keyword(s):

Time Course ◽

Near Infrared ◽

Cerebral Oxygenation ◽

Motor Task ◽

Hemoglobin Concentration ◽

Hemodynamic Response ◽

Blood Oxygenation ◽

Initial Increase ◽

Cerebral Hemodynamic ◽

Course Changes

We studied cerebral hemodynamic response to a sequential motor task in 56 subjects to investigate the time course and distribution of blood oxygenation changes as monitored by near-infrared spectroscopy (NIRS). To address whether response is modulated by different performance velocities, a group of subjects (n = 12) was examined while performing the motor task at 1, 2, and 3 Hz. The results demonstrate that 1) the NIRS response reflects localized changes in cerebral hemodynamics, 2) the response, consisting of an increase in oxygenated hemoglobin concentration [oxy-Hb] and a decrease in deoxygenated hemoglobin concentration ([deoxy-Hb]), is lateralized and increases in amplitude with higher performance rates, and 3) changes in [oxy-Hb] and [deoxy-Hb] differ in time course. Changes in [oxy-Hb] are biphasic, with a fast initial increase and a pronounced poststimulus undershoot. The stimulus-associated decrease in [deoxy-Hb] is monophasic, and response latency is greater. We conclude that NIRS is able to detect even small changes in cerebral hemodynamic response to functional stimulation.

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