Greater fat oxidation with diacylglycerol oil consumption for 14 days compared with triacylglycerol oil consumption in overweight men and women.

BACKGROUND: Several studies have reported increased fat oxidation with diacylglycerol (DAG) oil consumption. However, the effects of long-term DAG oil consumption on energy metabolism remain to be investigated. OBJECTIVE: The objective of this study was to compare the effects of 14 days of either DAG or triacylglycerol (TAG) oil consumption on substrate oxidation, energy expenditure (EE) and dietary fat oxidation. DESIGN: Eight males and six females participated in this randomized, double-blind, crossover feeding study. Each patient consumed the 14-day controlled test diet containing either 10 g day(-1) of DAG or TAG oil for acclimatization before a respiratory chamber measurement, followed by a 2-week washout period between diet treatments. Substrate oxidation and EE were measured in the respiratory chamber at the end of each dietary treatment. The patients consumed test oil as 15% of total caloric intake in the respiratory chamber (mean test oil intake was 36.1+/-6.6 g day(-1)). RESULTS: Twenty-four hour fat oxidation was significantly greater with 14 days of DAG oil consumption compared with TAG oil consumption (78.6+/-19.6 and 72.6+/-14.9 g day(-1), respectively, P<0.05). There were no differences in body weight or body composition between diet treatments. Dietary fat oxidation was determined using the recovery rate of (13)CO(2) in breath, and was significantly enhanced with DAG oil consumption compared with TAG oil consumption, measured over 22 h after ingestion of (13)C-labelled triolein. Resting metabolic rate (RMR) was significantly greater with DAG oil consumption compared with TAG oil consumption (1766+/-337 and 1680+/-316 kcal day(-1), respectively, P<0.05). CONCLUSION: Consumption of DAG oil for 14 days stimulates both fat oxidation and RMR compared with TAG oil consumption, which may explain the greater loss of body weight and body fat with DAG oil consumption that has been observed in weight-loss studies.

Role of Ca2+-sensitive protein kinase C in phenylephrine enhancement of Ca2+ sensitivity in rat tail artery.

We investigated the role of protein kinase C (PKC) isoforms on changes in sensitivity of contractile mechanisms to intracellular Ca(2+) (force /[Ca(2+)]i) by phenylephrine (0.1-100 microM) in rat tail arterial helical strips using simultaneous measurements of force and [Ca(2+)]i. Force/[Ca(2+)]Ii induced by phenylephrine was greater than that induced by 80 mM K+. Force/[Ca(2+)]i induced by phenylephrine in physiologic saline solution or low Ca(2+) solution was dependent on the agonist concentration. Removal of Ca(2+) completely abolished the phenylephrine-induced contraction. The PKC inhibitors staurosporine and calphostin C inhibited the increase in force/[Ca(2+)]i induced by phenylephrine to a much greater extent than that induced by 80 mM K+. LY379196, a specific PKCbeta inhibitor, did not inhibit the increase of calcium sensitivity due to phenylephrine. The classic PKC isoforms, alpha, betaI, and II not gamma were demonstrated in the artery by immunohistochemistry. These results suggest that in rat tail arterial smooth muscle, PKCalpha, and not beta or gamma, mediates the increase of changes in sensitivity of contractile mechanisms to intracellular Ca(2+) to high dose of alpha1 receptor stimulation (phenylephrine 100 microM) on nonphysiologic conditions.

Requirement of the Pseudomonas aeruginosa tonB gene for high-affinity iron acquisition and infection.

To investigate the contribution of the TonB protein to high-affinity iron acquisition in Pseudomonas aeruginosa, we constructed tonB-inactivated mutants from strain PAO1 and its derivative deficient in producing the siderophores pyoverdin and pyochelin. The tonB mutants could not grow in a free-iron-restricted medium prepared by apotransferrin addition, even though the medium was supplemented with each purified siderophore or with a heme source (hemoglobin or hemin). The tonB inactivation was shown to make P. aeruginosa unable to acquire iron from the transferrin with either siderophore. Introduction of a plasmid carrying the intact tonB gene restored growth of the tonB mutant of PAO1 in the free-iron-restricted medium without any supplements and restored growth of the tonB mutant of the siderophore-deficient derivative in the medium supplemented with pyoverdin, pyochelin, hemoglobin, or hemin. In addition, animal experiments showed that, in contrast to PAO1, the tonB mutant of PAO1 could not grow in vivo, such as in the muscles and lungs of immunosuppressed mice, and could not kill any of the animals. The in vivo growth ability and lethal virulence were also restored by introduction of the tonB-carrying plasmid in the tonB mutant. These results indicate clearly that the intact tonB gene-and, therefore, the TonB protein encoded by it-is essential for iron acquisition mediated by pyoverdin and pyochelin and via heme uptake in P. aeruginosa and suggest that the TonB-dependent iron acquisition may be essential for P. aeruginosa to infect the animal host.

Impact of siderophore production on Pseudomonas aeruginosa infections in immunosuppressed mice.

Pseudomonas aeruginosa produces siderophores, pyoverdin and pyochelin, for high-affinity iron uptake. To investigate their contribution to P. aeruginosa infections, we constructed allelic exchange mutants from strain PAO1 which were deficient in producing one or both of the siderophores. When inoculated into the calf muscles of immunosuppressed mice, pyochelin-deficient and pyoverdin-deficient mutants grew and killed the animals as efficiently as PAO1. In contrast, the pyochelin- and pyoverdin-deficient (double) mutant did not show lethal virulence, although it did infect the muscles. On the other hand, when inoculated intranasally, all mutants grew in the lungs and killed immunosuppressed mice. Compared with PAO1, however, the pyoverdin-deficient mutant and the double mutant grew poorly in the lungs, and the latter was significantly attenuated for virulence. Irrespective of the inoculation route, the pyoverdin-deficient and doubly deficient mutants detected in the blood were significantly less numerous than PAO1. Additionally, in vitro examination demonstrated that the growth of the double mutant was extremely reduced under a free-iron-restricted condition with apotransferrin but that the growth reduction was completely canceled by supplementation with hemoglobin as a heme source. These results suggest that both pyoverdin and pyochelin are required for efficient bacterial growth and full expression of virulence in P. aeruginosa infection, although pyoverdin may be comparatively more important for bacterial growth and dissemination. However, the siderophores were not always required for infection. It is possible that non-siderophore-mediated iron acquisition, such as via heme uptake, might also play an important role in P. aeruginosa infections.

A novel glycine-rich protein is associated with starch grain accumulation during anther development.

LIM14, originally identified as a lily gene associated with microsporogenesis, encodes a protein which has two distinct domains, one with glycine-serine repeats and the other with a hydrophobic signal peptide at the N-terminus. The putative LIM14 protein, however, is distinct from the glycine-rich cell wall proteins which have been described before. RNA analyses indicated that the LIM14 transcript is specifically detected in the anther from zygotene to young pollen stage. By using antibodies raised against recombinant LIM14 protein, we detected anther-specific 15 kDa protein. Immunofluorescence microscopy demonstrated that the LIM14 protein is associated with starch grains in the anther wall cells just prior to microspore mitosis and then accumulates at a higher level with the starch grains of immature pollen. We tagged LIM14 with the GUS and GFP reporter genes and introduced them into tobacco BY-2 cells. Analysis of the transformed cells revealed that the chimeric proteins are functional and specifically targeted to plastids. These results indicate that LIM14 is an anther-specific protein that may play a role in starch accumulation and amyloplast differentiation during anther development and pollen formation.

Vascular protective effects of ACE inhibitors and calcium antagonists: theoretical basis for a combination therapy in hypertension and other cardiovascular diseases.

Hypertension is an important cardiovascular risk factor. High blood pressure per se is not a disease but a hemodynamic alteration associated with vascular disease. Two classes of drugs are especially effective in lowering blood pressure and preventing cardiovascular complications, angiotensin converting enzyme (ACE) inhibitors and calcium antagonists. The hemodynamic effects of ACE inhibitors and calcium antagonists are complementary. While ACE inhibitors inhibit the renin-angiotensin system and reduce sympathetic outflow, calcium antagonists dilate large conduit and resistance arteries. Certain calcium antagonists, such as verapamil, lower heart rate. In the blood vessel wall, the local vascular effects of ACE inhibitors and calcium antagonists are also complementary. While ACE inhibitors inhibit activation of angiotensin I into angiotensin II and prevent the breakdown of bradykinin (which stimulates nitric oxide and prostacyclin formation), calcium antagonists inhibit the effects of vasoconstrictor hormones such as angiotensin II at the level of vascular smooth muscle by reducing calcium inflow and facilitating the vasodilator effects of nitric oxide. Calcium antagonists reduce smooth muscle cell proliferation and atherosclerosis. In hypertensive animals, verapamil and trandolapril normalize endothelial dysfunction. In large angiographic trials, nifedipine and nicardipine reduced the development of new atherosclerotic plaques. After myocardial infarction, verapamil reduces mortality and cardiac events in patients without heart failure. In contrast, ACE inhibitors are effective after myocardial infarction in patients with impaired left ventricular function. Urinary albumin excretion rate decreases during ACE inhibitor therapy or with a calcium antagonist such as verapamil; combination of the two drugs has an additive effect. In resistance arteries, hypertension is associated with an increased media/lumen ratio. ACE inhibitors, but not beta-blockers, markedly improve these structural changes. In summary, ACE inhibitors and calcium antagonists have a complementary profile, both in their hemodynamic and local vascular action. Hence, combination therapy with these two classes of drugs appears particularly useful in patients with hypertension, not only to lower blood pressure, but hopefully to achieve improved cardiovascular protection.

Pharmacological profile of gastric mucosal protection by marmin and nobiletin from a traditional herbal medicine, Aurantii fructus immaturus.

We studied the effects of marmin and nobiletin on the experimental acute gastric lesions, gastric transmucosal potential difference (PD) and gastric motor activity in rats and the contractions of isolated guinea pig ileum. Oral administration of marmin and nobiletin inhibited both the appearance of ethanol-induced gastric hemorrhagic lesions dose-dependently in a dose range of 10-50 mg/kg, with ED50 values for marmin and nobiletin being 17.2 and 8.0 mg/kg, respectively. However, marmin and nobiletin had minimal effects on aspirin-induced gastric lesions at a dose of 50 mg/kg, respectively. Marmin and nobiletin had no significant influence on the basal PD. Intragastrical administration of marmin and nobiletin at a dose of 25 mg/kg significantly prevented the PD reduction induced by ethanol. Both marmin and nobiletin given intragastrically at 25 mg/kg significantly inhibited gastric motor activity measured as intraluminal pressure recordings. Marmin and nobiletin exhibited concentration-dependent relaxations of contractions induced by acetylcholine, transmural electrical stimulation and histamine in isolated guinea pig ileum, respectively. These findings suggest that the anti-ulcer effects of marmin and nobiletin are ascribed primarily to the maintenance of the mucosal barrier integrity and inhibition of gastric motor activity and secondarily due to the prevention of the effects of endogenous acetylcholine and histamine.

[Pharmacological studies on antidiarrheal effects of a preparation containing berberine and geranii herba].

We studied the effects of a preparation containing Berberine and Geranii Herba (BGH) on different diarrheal models of mice and the contractions of isolated guinea pig intestinal smooth muscle, comparing these effects with those of a preparation containing creosote (CSG) and loperamide (LP). BGH, as well as CSG and LP, significantly inhibited the diarrhea induced by castor oil or BaCl2, but not the diarrhea induced by pilocarpine or serotonin. BGH inhibited ACh-, Ba(2+)- or electrical stimulation (ES)-induced contraction of the ileum or colon at concentrations from 10(-6) to 10(-4) g/ml. On the other hand, the inhibitory effect of CSG on the ES-induced contraction was about one hundred times stronger than that on ACh- or Ba(2+)-induced contraction. The order of the inhibitory potency of LP on contractions of the ileum in this test was ES > Ba2+ > ACh, and LP showed stronger inhibition against the contraction of the ileum than that of the colon. These results suggest that BGH exerts its antidiarrheal action by inhibiting intestinal movement, and the mechanism of action of BGH may differ from those of CSG or LP.

Roles of sulfhydryl compounds in the gastric mucosal protection of the herb drugs composing oren-gedoku-to (a traditional herbal medicine).

We investigated the involvement of sulfhydryl compounds in the cytoprotective effect of each component herb drug composing Oren-gedoku-to (OGT) against ethanol-induced gastric lesions and potential difference (PD) reduction in comparison with that of OGT in rats. Pretreatment with N-ethylmaleimide (NEM) significantly blocked the cytoprotective effects of OGT, Coptidis rhizoma and Phellodendri cortex, but did not block the cytoprotective effects of Gardeniae fructus and Scutellariae radix. The inhibitory effects of OGT, Coptidis rhizoma and Phellodendri cortex against the PD reduction disappeared in the presence of NEM or diethyldithiocarbamate (DDC), whereas NEM or DDC had little or no effect with Gardeniae fructus and Scutellariae radix. These results suggest that the gastric mucosal protection of Coptidis rhizoma and Phellodendri cortex may be ascribed to the reinforcement of mucosal barrier resistance through endogenous sulfhydryl compounds and DDC-sensitive compounds, but those of Gardeniae fructus and Scutellariae radix may be independent of NEM- or DDC-sensitive compounds.

[The mechanism of the inhibitory effects of oren-gedoku-to (OGT) on gastric acid secretion in rats].

The effect of oren-gedoku-to (OGT) on gastric acid secretion was examined in the perfused stomach of anesthetized rats. OGT (10-100 mg/kg) given intraperitoneally dose-dependently inhibited the gastric acid secretion stimulated by intracerebroventricular DN-1417, an analogue of TRH, but failed to inhibit the acid secretion stimulated by intracerebroventricular baclofen, an analogue of GABA. The inhibitory effect of OGT on DN-1417-induced acid secretion was antagonized by haloperidol (0.3 and 1.0 mg/kg, i.p.), a dopamine-1/2 antagonist or sulpiride (100 mg/kg, i.p.), a dopamine-2 antagonist; and it was also reversed by yohimbine (0.3 mg/kg, i.p.), an alpha-2 adrenergic antagonist, and prazosin, an alpha-1 antagonist. These results suggest that the ability of OGT to reduce acid secretion is mediated via not only dopamine receptors but also alpha-2 adrenoceptors.

A possible mechanism for the gastric mucosal protection by oren-gedoku-to (OGT), a traditional herbal medicine.

We investigated the involvement of sulfhydryl-compounds in the cytoprotective effect of Oren-gedoku-to (OGT) against ethanol-induced gastric lesions and potential difference (PD) reduction in comparison with those of sucralfate and glutathione in rats. Pretreatment with indomethacin (IND) had little influence on the cytoprotective effects of OGT and glutathione, but attenuated the effect of sucralfate. Pretreatment with N-ethylmaleimide (NEM) blocked the cytoprotective effects of these three drugs. Pretreatment with iodoacetamide diminished the cytoprotection of OGT and glutathione, but had little effect on that of sucralfate. The cytoprotective activities of OGT, glutathione and sucralfate were little affected by pretreatment with 6,6'-dithiodinicotinic acid. The inhibitory effects of OGT and glutathione against the PD reduction were completely blocked by pretreatment with NEM, while they were not influenced by pretreatment with IND. On the other hand, the inhibitory effect of sucralfate disappeared both by IND and NEM. These results suggest that the cytoprotective effect of OGT may be mediated by endogenous sulfhydryl compounds, but not by endogenous prostaglandins in the gastric mucosa.

Features of the anti-ulcer effects of Oren-gedoku-to (a traditional Chinese medicine) and its component herb drugs.

This report describes the features of the anti-ulcer effect of Oren-gedoku-to (OGT, a traditional Chinese medicine) and its component herb drugs. Coptidis rhizoma and Phellodendri cortex given orally dose-dependently inhibited the appearance of ethanol-induced gastric hemorrhagic lesions in a dose range of 25-100 mg/kg, but the formation of the lesions was not prevented by Scutellariae radix or Gardeniae fructus at the same doses. Coptidis rhizoma, Phellodendri cortex and Gardeniae fructus inhibited the gastric potential difference (PD) reduction induced by ethanol, whereas Scutellariae radix did not prevent the decrease in the PD reduction caused by ethanol. Phellodendri cortex, Scutellariae radix and Gardeniae fructus had no significant influence on the basal PD, while Coptidis rhizoma increased the basal PD. The four herb drugs prevented gastric acid secretion induced by 2-deoxy-D-glucose, but the three drugs except for Phellodendri cortex showed little effect on pentagastrin-stimulation. These results suggest that the gastric mucosal protection by OGT is ascribed to Coptidis rhizoma and Phellodendri cortex, and its antisecretory effect is due to the four drugs.

[Pharmacological studies of some traditional Chinese medicines on gastric functions. (2) The effects of oren-gedoku-to (OGT), san'o-syasin-to (SST), antyu-san (AS) and dai-saiko-to (DST) on gastric acid secretion in rats].

The effects of OGT, SST, AS and DST on gastric acid secretion stimulated by histamine, pentagastrin, carbachol and 2-deoxy-D-glucose (2-DG) were studied in the perfused stomach of anesthetized rats, and these effects were compared with those of cimetidine, 16,16-dimethyl-prostaglandin E2(DMPGE2) and atropine. OGT and SST showed little or no effect on the acid secretion induced by histamine or carbachol at doses of 100 mg/kg, whereas the former showed a moderate inhibition and the latter showed a marked one against pentagastrin-stimulation. AS and DST had no effect on the acid secretion induced by carbachol at doses of 100 mg/kg, whereas they showed a moderate inhibition against histamine-stimulation, and the latter showed a significant inhibition against pentagastrin-stimulation. Further, each of the above four drugs showed a significant effect on 2-DG-stimulation. Cimetidine (1-10 mg/kg) inhibited gastric acid secretion stimulated by histamine, pentagastrin, carbachol or 2-DG in a dose-dependent manner. Similarly, DMPGE2 (10 micrograms/kg) strongly inhibited acid secretion induced by the four secretagogues. Atropine (50 micrograms/kg) inhibited acid secretion induced by carbachol or 2-DG, but not that by histamine or pentagastrin. These results suggest that OGT, SST, AS and DST clearly affect the mechanism of gastric acid secretion, and the site of action of OGT may differ from those of SST, AS and DST.

[Pharmacological studies on the effects of some traditional Chinese medicines on gastric functions. (3) The effects of oren-gedoku-to (OGT), san'o-syasin-to (SST), antyu-san (AS) and dai-saiko-to (DST) on ethanol- and aspirin-induced gastric lesions in rats].

The effects of OGT, SST, AS and DST on ethanol- and aspirin-induced gastric hemorrhagic lesions in rats were studied in comparison with those of sucralfate, 16,16-dimethyl-prostaglandin E2 (DMPGE2) and cimetidine. 1) OGT given orally at doses of 25-250 mg/kg protected gastric mucosa from injury induced by ethanol or aspirin. 2) SST prevented the appearance of aspirin-induced lesions at doses more than 25 mg/kg, and ethanol-induced lesions at 250 and 500 mg/kg. 3) AS and DST inhibited aspirin-induced lesions at more than 250 mg/kg and inhibited ethanol-induced lesions at 500 mg/kg. 4) Sucralfate (500 mg/kg) significantly prevented ethanol- and aspirin-induced lesions. DMPGE2 significantly inhibited ethanol-induced lesions at doses more than 0.1 micrograms/kg, and it inhibited aspirin-induced lesions dose-dependently at doses ranging from 0.1 to 5 micrograms/kg. Cimetidine significantly inhibited aspirin-induced lesions at doses of 10-250 mg/kg and inhibited ethanol-induced lesions at doses of 100 and 250 mg/kg. These results suggest that OGT, SST, AS and DST have a prophylactic effect on ulcerogenics, and the potency of OGT may be superior to those of SST, AS and DST.

[Pharmacological studies of some blended traditional Chinese medicines on gastric functions. (1). The effects of oren-gedoku-to (OGT), san'o-syasin-to (SST), antyu-san (AS) and dai-saiko-to (DST) on ethanol- and aspirin-induced injury of gastric mucosal barrier].

We studied the effects of OGT, SST, AS and DST on ethanol- and aspirin-induced reduction of gastric transmucosal potential difference (PD) in rats as an index of gastric mucosal damage, and these effects were compared with those of sucralfate, 16,16-dimethyl-prostaglandin E2 (DMPGE2), cimetidine and proglumide. 1) OGT and SST as well as sucralfate and DMPGE2 significantly inhibited the PD reduction induced by ethanol and aspirin. 2) AS and DST as well as cimetidine significantly inhibited the PD reduction induced by aspirin, but not by ethanol. 3) Proglumide did not influence the PD reduction induced by ethanol and aspirin. 4) OGT alone, like sucralfate and proglumide, showed no influence on the basal PD, while SST, AS and DST, like DMPGE2 and cimetidine, increased the basal PD. These results suggest that OGT, SST, AS and DST protect the gastric mucosal barrier, and this effect of OGT differs from that of SST, AS and DST.

Effect of sex hormones on hypoprothrombinemia induced by N-methyltetrazolethiol in rats.

N-Methyltetrazolethiol (NMTT) increased prothrombin time (PT) and decreased plasma factor VII and prothrombin levels only in vitamin K-deficient male rats. In female rats identical treatment with NMTT did not produce hypoprothrombinemia. Conventional and germ-free rats displayed no significant difference in the manifestation of hypoprothrombinemia, but the increase of PT in NMTT-treated vitamin K-deficient rats was greater in the germ-free males. Estradiol administration or castration of male rats retarded manifestation of vitamin K deficient syndromes such as increases of PT and activated partial thromboplastin time (APTT), decreases of plasma factor VII and prothrombin levels, and increases of plasma and liver descarboxyprothrombin (PIVKA) levels, and testosterone injection to the castrated rats restored these changes. In female rats testosterone treatment or castration enhanced the manifestation of hypoprothrombinemia and estradiol treatment to the castrated females retarded it. Gamma-glutamyl-carboxylase activity was increased by vitamin K-deficiency but not inhibited by testosterone or NMTT. These data suggest that estrogen protects the rat against manifestation of hypoprothrombinemia even with NMTT treatment, while androgen enhances vitamin K deficiency, and supplementation of vitamin K prevents its deficiency in NMTT-treated rats.