Iron deficiency diminishes gallbladder neuronal nitric oxide synthase

Changes and Correlations of the Intestinal Flora and Liver Metabolite Profiles in Mice With Gallstones

There is increasing appreciation for the roles of the gut-liver axis in liver and gall diseases. Specific gut microbes are associated with susceptibility to gallstone diseases, while the relationship between intestinal flora and liver metabolism in the formation of gallstones remains unclear. In this study, an experimental group of model mice was given a lithogenic diet, and a control group was given a normal diet. Both groups were fed for 8 weeks. Integrating 16S rRNA gene sequencing and non-targeted metabolomics to explore the impact of the lithogenic diet on intestinal flora and liver metabolism, Spearman correlation analysis reveals the network of relationships between the intestine and liver. Our findings showed that the gut microbiome and liver metabolome compositions of the test group were significantly changed compared with those of the normal group. Through our research, biomarkers of gallstones were identified at the phylum (5), class (5), order (5), family (7), and genus levels. We predicted the function of the differential flora. We analyzed the liver metabolism of mice with gallstones paired with their flora, and the results showed that there were 138 different metabolites between the two groups. The metabolic pathways enriched by these differential metabolites are highly consistent with the functions of the disordered flora. We focused on an analysis of the relationship between deoxycholic acid, asymmetric dimethylarginine, glucosamine, tauroursodeoxycholic acid, and the disordered flora. This provides a basis for the establishment of the intestine-liver axis in gallstone disease. This research provides a theoretical basis for the research and development of probiotics and prebiotics.

Oral Administration of Nanoiron Sulfide Supernatant for the Treatment of Gallbladder Stones with Chronic Cholecystitis

Cholelithiasis with chronic cholecystitis is prevalent and threatens human health. Most cholecystitis caused by bacterial infection or biofilms is accompanied by gallstones in the clinic, making gallbladder removal the only effective solution. Here, we provide a strategy to eliminate gallstone biofilms and dissolve gallstones by oral administration of a supernatant derived from nanoscale iron sulfide (nFeS supernatant). First, by using gallstones obtained from the clinic, we simulated biofilm formation on gallstones and tested the antibacterial activity of a nFeS supernatant in vitro. We found that the supernatant kills bacteria with a 5-log reduction in viability and destroys the biofilm structure. Smashed gallstones coincubated with E. coli biofilms promote gallstone formation, while nFeS supernatant can inhibit this process. Second, by using a murine (C57BL/6) model of cholelithiasis and cholecystitis, we tested the antibacterial efficacy and therapeutic effects of nFeS supernatant on cholelithiasis in vivo. Animal experimental data show that oral administration of nFeS supernatant can reduce 60% of bacteria in the gallbladder and, remarkably, remove gallstones with 2 days of treatment compared with clinical drug combinations (chenodeoxycholid acid and ciprofloxacin). Third, by performing protein abundance analysis of L02 cells and mouse livers, we observed the changes in CYP7a1, HMGCR, and SCP2 expression, indicating that the nFeS supernatant can also regulate cholesterol metabolism to prevent gallstone formation. Finally, hematologic biochemistry analysis and high-throughput sequencing technology show that the nFeS supernatant possesses high biocompatibility. Therefore, our work demonstrates that the nFeS supernatant may be a potential regimen for the treatment of cholelithiasis and cholecystitis by oral administration.

To study serum iron levels in patients of gall bladder stone disease and to compare with healthy individuals

Gallstone disease is a common gastrointestinal problem in day-to-day practice. The Old concept that a typical gallstone sufferer is fat, fertile, flatulent female of 50. This is partially true as the disease has been found in women soon after their first delivery who are thin and underweight and in males also. Conditions that favor the formation of cholesterol gallstones are super saturation of bile with cholesterol, kinetically favorable nucleation and presence of cholesterol crystals in the gall bladder long enough to agglomerate into a stone. Recent studies have defined the role of trace elements (Fe, Ca, Zn and Cu) and defective pH in the formation of gallstones. The aim of the study was to correlate iron-deficiency anemia with gallstone disease. To estimate the serum ferritin level as a diagnostic tool of iron deficiency anemia in patients with gallstone disease, this prospective study of 100 patients was conducted over a period of 24 months in the Department of General Surgery, Jaipur Golden Hospital, New Delhi, India. Serum cholesterol, iron and ferritin levels were compared in patients having gallstones and healthy individuals. A low serum iron level is a factor in bile super saturation with respect to cholesterol, leading to gallstone formation.

Biliary proteins and their redox status changes in gallstone patients

BACKGROUND

Proteins might act as pronucleating agents of cholesterol crystallization in bile. However, little is known about the redox status of biliary proteins in humans and their interaction with crystallization of biliary cholesterol.

MATERIALS AND METHODS

Gallbladder biles were obtained at cholecystectomy from 86 symptomatic patients with either cholesterol gallstones (32 multiple and 32 solitary stones) or pigment stones (n = 22), and studied for protein redox status [carbonyl and sulfhydryl (PSH) concentrations], total lipid and protein levels and cholesterol saturation index (CSI). First appearance of cholesterol crystals in ultrafiltered bile (crystal observation time, COT) was studied with polarizing light microscopy during 21 days.

RESULTS

Patients with cholesterol stones had significantly shorter COT (3 days vs. >21 days, P < 0.05), higher CSI (149 +/- 10% vs. 97 +/- 7%, P < 0.05) and higher total biliary proteins (1.96 +/- 0.1 mg mL(-1) vs. 0.55 +/- 0.1 mg mL(-1), P < 0.05) than patients with pigment stones. Patients with cholesterol stones had significantly lower (P < 0.05) level of protein sulfhydryl concentrations (18 +/- 4 nmol mg(-1) protein vs. 49 +/- 16 nmol mg(-1) protein), while total lipid and carbonyl proteins concentrations were similar between cholesterol and pigment stone patients. Crystallization probability was influenced by the number/type of gallstones (multiple > solitary > pigment stones, P = 0.009) and total protein concentration (high > low levels, P = 0.004). COT was negatively correlated with total protein content (r = -0.45, P = 0.03).

CONCLUSIONS

Biles with cholesterol stones show high CSI and total protein concentration, and rapid COT, which is even faster in patients with multiple stones and high protein concentration. Low PSH levels in cholesterol stone patients point to a biochemical shift, potentially able to affect cholesterol crystallization.

Patients with iron deficiency anemia have an increased prevalence of gallstones

We determined the frequency of gallstones (GS) in iron deficiency anemia (IDA) patients and evaluated factors that could affect GS formation-like lipid levels and gallbladder (GB) motilities of the patients. One hundred and eleven IDA patients (88 females, 23 males; median age, 42) and 81 healthy controls (68 females, 13 males; median age, 42) were included into our study. The clinical findings of all IDA patients were recorded down; biochemical values and body mass index (BMI) were determined; and abdominal ultrasonography was performed. In addition, GB emptying was monitored by ultrasound at 30-min intervals for 2 h after a mixed meal in randomly chosen, age-matched 25 IDA patients and 26 controls. Fasting volume (FV), residual volume (RV), and ejection fraction (EF) for all GBs were determined. The frequency of GS plus cholecystectomy was significantly higher in IDA patients (15 cases, 13.5%) than in the control group (five cases, 6.2%, p = 0.048). IDA patients with GS plus cholecystectomy were older than those without GS plus cholecystectomy (p < 0.001). FV and EF did not differ between IDA and control groups (p > 0.05). On the other hand, RV was significantly higher in IDA group than in controls (p = 0.035). The frequency of GS in IDA patients was significantly higher than in controls. The increased prevalence of GS in IDA might be explained with impaired GB motility.

Biliary lipids and cholesterol crystal formation in leptin-deficient obese mice

BACKGROUND

Obesity is often associated with increased biliary cholesterol secretion resulting in cholesterol gallstone formation. We have previously demonstrated that leptin-deficient C57Bl/6J Lep ob obese mice have abnormal biliary motility and are prone to cholesterol crystal formation. In addition, others have demonstrated that leptin-deficient mice when fed a lithogenic diet for eight weeks are not prone to gallstone formation. However, the biliary lipid and in vivo cholesterol crystal response of homozygous and heterozygous leptin-deficient mice to four weeks on a lithogenic diet has not been studied. Therefore, we tested the hypothesis that lithogenic diets influence gallbladder bile composition, serum lipids and cholesterol crystal formation in homozygous and heterozygous leptin-deficient mice compared to normal lean controls.

METHODS

319 female lean control mice, 280 heterozygous lep ob obese mice and 117 homozygous lep ob obese mice were studied. Mice were fed either a lithogenic or control non-lithogenic chow diet for four weeks. Gallbladder volumes were measured, and bile was pooled to calculate cholesterol saturation indices. Serum cholesterol, glucose, and leptin levels were determined. Hepatic fat vacuoles were counted, and bile was observed microscopically for cholesterol crystal formation.

RESULTS

The lithogenic diet and mouse strain influenced body and liver weights, gallbladder volume, cholesterol crystal formation, serum cholesterol, glucose and leptin levels and hepatic fat vacuole numbers. However, only diet, not strain, altered biliary cholesterol saturation.

CONCLUSION

The association among obesity, leptin, and gallstone formation may be primarily related to altered gallbladder motility and cholesterol crystal formation and only secondarily to biliary cholesterol saturation.

Esophageal contractions and oropharyngeal and esophageal transits in patients with iron deficiency anemia

OBJECTIVE

Patients with iron deficiency may have reduced power of the pharyngeal muscle for bolus propulsion into the esophagus. We hypothesized that esophageal muscle is similarly impaired.

METHODS

We studied the oropharyngeal and esophageal transits and esophageal motility of 12 patients (11 women) aged 31-50 yr (median 36 yr) with iron deficiency anemia (serum iron less than 40 microg/dl) and 17 normal volunteers (16 women) aged 26-52 yr (median 37 yr) with serum iron greater than 60 microg/dl. The esophageal motility was studied by the manometric method, with continuous perfusion and 10 swallows of a 2-ml bolus of water alternated with 10 swallows of a 7-ml bolus; and the oropharyngeal and esophageal transits were studied by scintigraphy, with swallows of a 10-ml bolus for the study of oropharyngeal transit and of a 10-ml bolus for the study of esophageal transit. Motility and transit were studied in the supine position.

RESULTS

The amplitude, duration and area under the curve of contractions were lower in patients than in volunteers. There were no differences in peristaltic contraction velocity, lower esophageal sphincter pressure, and lower esophageal sphincter relaxation duration. There was no difference in oropharyngeal transit. In the esophagus the transit was slower in patients than in volunteers. The time needed by the scintigraphic activity to reach a peak in the proximal esophagus was longer in patients than in volunteers.

CONCLUSIONS

Iron deficiency may decrease esophageal contractions and impair esophageal transit.

Investigation of the mechanism of nicotine-induced relaxation in guinea pig gallbladder

BACKGROUND

Muscular contraction of the gallbladder is the primary determinant of bile delivery into duedonum. Gallbladder filling and emptying are influenced by both inhibitory and excitatory stimuli, and NO plays a key role in normal relaxation. In this study, to determine whether nicotine acts on the gallbladder muscle, the mechanism of its effect on strips of guinea pig gallbladder was studied in vitro.

MATERIALS AND METHODS

Guinea pig gallbladder muscle strips were mounted in organ bath with modified Krebs-Henseleit solution and aerated with Carbogen. Tension was measured with isometric force transducers, and muscle relaxation was expressed as percent decrease of precontraction induced by carbachol.

RESULTS

Nicotine produced concentration dependent relaxation when preparations were precontracted by carbachol (10(-6) M). Nicotine-induced relaxation was 51.6 +/- 3.2% of phenylephrine contraction and was not affected by guanethidine (10(-5) M), propranolol (10(-6) M), hexamethonium (10(-4) M), indomethacin (10(-5) M), N(w)-nitro L-arginine methyl ester (L-NAME) (3 x 10(-5) M), methylene blue (10(-5) M), glibenclamide (10(-5) M), clotrimazole (10(-6) M), tetraethylammonium (3 x 10(-4) M), or 4-aminopyridine (10(-3) M). Nicotine did not exhibit a calcium antagonizing effect.

CONCLUSIONS

From these results, we concluded that nicotine-induced relaxation of the guinea pig gallbladder is not mediated by the release of noradrenaline, nitric oxide (NO), prostaglandins, or a related substance, or by the activation of potassium channels, or by the stimulation of nicotinic cholinoceptors. Further work is needed to determine the cellular mechanism(s) of action by which nicotine acts on gallbladder smooth muscle.

Regulation of nitric oxide synthesis by dietary factors

Nitric oxide (NO) is synthesized from L-arginine by NO synthase (NOS). As an endothelium-derived relaxing factor, a mediator of immune responses, a neurotransmitter, a cytotoxic free radical, and a signaling molecule, NO plays crucial roles in virtually every cellular and organ function in the body. The discovery of NO synthesis has unified traditionally diverse research areas in nutrition, physiology, immunology, pathology, and neuroscience. Increasing evidence over the past decade shows that many dietary factors, including protein, amino acids, glucose, fructose, cholesterol, fatty acids, vitamins, minerals, phytoestrogens, ethanol, and polyphenols, are either beneficial to health or contribute to the pathogenesis of chronic diseases partially through modulation of NO production by inducible NOS or constitutive NOS. Although most published studies have focused on only a single nutrient and have generated new and exciting knowledge, future studies are necessary to investigate the interactions of dietary factors on NO synthesis and to define the underlying molecular mechanisms.

Iron deficiency transiently suppresses biliary neuronal nitric oxide synthase

BACKGROUND

Iron deficiency results in altered gallbladder and sphincter of Oddi (SO) motility and cholesterol crystal formation. In addition, gallbladder neuronal nitric oxide synthase (nNOS) has been shown to be markedly reduced after 8 weeks on an iron-deficient diet. However, the effects of prolonged iron deficiency on gallbladder and SO nNOS as well as crystal formation have not been determined. Therefore, we tested the hypothesis that iron deficiency would downregulate both gallbladder and SO nNOS expression and that nNOS downregulation and cholesterol crystal formation would progress over time.

MATERIALS AND METHODS

Thirty-eight adult female prairie dogs were fed either an ironsupplemented (Fe+) (200 ppm) or an iron-deficient (Fe-) (8 ppm) diet for 8 weeks (Fe+ n = 9, Fe- n = 10) or 16 weeks (Fe+ n = 9, Fe- n = 10). Blood hemoglobin (HbG) was measured; gallbladder cholesterol crystals were counted; and cholesterol saturation indices (CSI) were calculated. Gallbladder and SO nNOS levels were measured by Western blot.

RESULTS

The Fe+ prairie dogs had significantly higher HbG than the Fe- animals (16.9 +/- 0.6 g/dl vs 15.2 +/- 0.5 g/dl, respectively, P < 0.05) after 8 weeks. This difference was even greater after 16 weeks (16.1 +/- 0.4 g/dl vs 14.0 +/- 0.5 g/dl, P < 0.01). At 8 weeks, more cholesterol crystals per 10 HPF were observed in the Fe- animals (0.4 +/- 0.3 vs 1.6 +/- 0.4 per 10 HPF, P < 0.05). This difference was even greater after 16 weeks (0.0 +/- 0.0 vs 52.6 +/- 25.3 per 10 HPF, P < 0.01). No difference in the CSI was observed in the four groups. Iron deficiency decreased the nNOS/beta-actin protein levels in the gallbladder and SO at 8 weeks (57.0 +/- 29.6 vs 7.4 +/- 2.6, gallbladder, P < 0.05) (98.4 +/- 39.7 vs 29.9 +/- 11.0, SO, P = 0.09), but these levels returned to baseline at 16 weeks.

CONCLUSIONS

We conclude that iron deficiency acutely suppresses gallbladder and SO nNOS, and that compensatory mechanisms return nNOS to baseline levels while cholesterol crystal formation increases over time.