Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “HYDROCHLORIC ACID”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,477 records · Page 82Linked to original sources
PubMed1994

The effect of esophageal mechanical and chemical stimuli on salivary mucin secretion in healthy individuals.

Because of a newly developed model of esophageal perfusion in humans, the authors could study the role of esophago-salivary reflex in salivary neutral and acidic mucin output. The basal rate of neutral mucin output was 0.24 +/- 0.06 mg per minute. Placement of intraesophageal tubing and inflation of balloons resulted in a highly significant increase in salivary mucin output (2.10 +/- 0.22 mg per minute; p < 0.00001). However, implementation of esophageal perfusion with saline resulted in a significant decline of salivary mucin output (1.28 +/- 0.10 mg/mL NaCl4 versus 2.08 +/- 0.24 mg/mL NaCl1; p < 0.001). Esophageal perfusion with hydrochloric acid prevented the decline of salivary mucin output observed during perfusion with saline, whereas infusion of hydrochloric acid/pepsin resulted in a significant enhancement of salivary mucin output (2.89 +/- 0.31 mg per minute; p < 0.01). Therefore, mechanical and chemical stimulations resulted in an overall 9-fold and 12-fold increase in the rate of salivary mucin output over the basal value, respectively. The basal rate of acidic mucin secretion was 0.26 +/- 0.06 mg per minute. After placement of intraesophageal tubing, inflation of balloons, perfusion hydrochloric acid, or hydrochloric acid-pepsin solution, a significant enhancement in the rate of salivary acidic mucin output, similar to that observed during measurement of neutral mucin, was observed. Therefore, during mechanical and chemical stimulation, the rate of salivary acidic mucin output increased 7.3-fold and 11.1-fold over the basal value, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Temperature, pH value, acid load and filtrability of normal human erythrocytes: in vitro studies--possible significance for hyperthermic hyperacidotic tumor therapy].

Normal human red blood cells, taken from healthy young men were separated from the other blood cells with the aid of a density centrifugation. The cells were titrated with acid to a defined minimal pH value and retitrated with sodium hydroxide to normal pH (7.4 +/- 0.1) two times. After each of the two acid loadings, which were done at 37 degrees C (normothermia) and 43 degrees C (hyperthermia) the so-called specific filtration time (FZsp) is determined with 5 microns Nuclepore membranes under 4% hematocrit. FZsp is a measure for the relative flow resistance of the red blood cells they have with the filtering membrane. FZsp was found to be irreversibly increased by the twofold acid load. The effect increases with decreasing pH and increasing temperature. Hydrochloric acid has a greater effect than lactic acid.

Acid-Base Equilibrium↗
PubMed1976

Changes of activity of alkaline and acid phosphatase in the rabbit eye in the early phase of alkaline and acid injury.

Rabbit corneas were burned either with 1.0 N sodium hydroxide or 1.0 N hydrochloric acid. Enzyme activities of alkaline and acid phosphatases were examined spectrophotometrically in the homogenates of cornea, iris, aqueous humor and vitreous body. On the 3rd day after alkaline as well as acid burn, a significant decrease of both enzyme activities was produced as compared with untreated animals. A more pronounced change was found in the case of alkaline injuries. With both kinds of caustic agents the decrease of acid phosphatase activity was more striking than that of the alkaline phosphatase. Advantages and shortcomings of biochemical and histochemical enzymatic determinations in experimental ocular inflammations are briefly discussed.

Acid Phosphatase↗
PubMed1992

Continuous versus intermittent acid exposure in production of esophagitis in feline model.

Our morphometric feline model of acid-induced esophageal damage histologically resembles human reflux esophagitis. The histologic scoring system includes intensity and linear extent of basal cell hyperplasia, intraepithelial and subepithelial segmented leukocytes, and ulcers. Each of these four categories is scored from 0 to 4, for a potential total score of 16. Some reports have indicated that the long-duration acid exposure episodes during recumbent nighttime reflux are apt to be associated with greater injury than shorter episodes during daytime upright exposure. We tested the hypothesis that longer single exposures to acid would incite greater morphologic damage in the cat than would multiple, shorter acid exposures. To study the influence of continuous versus intermittent hydrochloric acid exposure, groups of six cats each were infused continuously (single infusion) for 15, 20, or 30 min, and compared with cats infused for 2-min acid infusion times. Our studies indicate that total acid exposure and mucosal damage are more likely to be greater after multiple episodes of the same total duration with adequate clearing (ie, awake upright reflux) than after single long episodes of acid exposure that are poorly cleared (ie, sleeping).

Analysis of Variance↗
PubMed1998

Mechanism of acid-induced mesenteric hyperemia in rats.

The mesenteric hyperemia induced by intraduodenal application of hydrochloric acid (HCl) is mediated in part by capsaicin-sensitive afferent nerves. Antagonist of capsaicin-sensitive receptors (capsazepine) and blocker of capsaicin-sensitive cation channels (ruthenium red) have been described. We employed these tools to dissect the mechanism of regulation of mesenteric hyperemia induced by intraduodenal administration of HCl. Subcutaneous 100 micromol/kg capsazepine or intraduodenal 0.1% ruthenium red was administered to pentobarbital anesthetized rats. Then, 2.5 ml/kg of 640 microM capsaicin or 0.1 N HCl was administered intraduodenally. The mesenteric hyperemic responses were recorded. The results demonstrated that in a dose that decreased the mesenteric hyperemia induced by intraduodenal capsaicin, capsazepine failed to attenuate the mesenteric vasodilatory effect of intraduodenal HCl. Ruthenium red significantly attenuated the mesenteric hyperemia after intraduodenal capsaicin and HCl. These in vivo data provide the first functional evidence for the existence of capsazepine-sensitive capsaicin receptors and cation channel complexes in the rat duodenal and intestinal mucosa. The capsaicin- and HCl-sensitive receptors are unlikely to be functionally identical in these locations. The ruthenium red-sensitive cation channels appear to mediate the capsaicin- and HCl-induced mesenteric hyperemia.

Animals↗
PubMed2004

A prospective, randomized, blind comparison between saline, calcium gluconate and diphoterine for washing skin acid injuries in rats: effects on substance P and beta-endorphin release.

BACKGROUND AND OBJECTIVE: A randomized, blind study to evaluate the effects on beta-endorphin and substance P release after washing acid burns with 0.9% saline, calcium gluconate or diphoterine in a model of chemical burn in rats. METHODS: Twenty Sprague-Dawley rats (approximate weight 250 g) were anaesthetized with ketamine (30 mg kg(-1) intramuscularly) and then given an acid injury on the back skin with 0.5 mL of hydrochloric acid 52%. The rats were then randomly allocated to receive no washing (control group, n = 5), washing with normal saline (0.9% NaCl) (n = 5), 10% calcium gluconate (n = 5) or diphoterine (n = 5). Blood concentrations of substance P and beta-endorphin were measured 6 h, 48 h and 7 days after the chemical burn. An independent blinded observer evaluated wound healing at the 7th day. RESULTS: Seven days after burn wound healing was almost complete only in rats treated with diphoterine. Plasma concentrations of substance P were lower in rats receiving skin flushing with diphoterine compared to the other groups at 6 and 48 h after acid burn (P < 0.05 and P < 0.05, respectively); this was also associated with higher concentrations of beta-endorphin at day 7 (P < 0.05). CONCLUSIONS: Skin flushing with diphoterine reduced substance P release during the first 48 h after burn, and was associated with better wound healing and higher concentrations of beta-endorphin 7 days later when compared with normal saline or 10% calcium gluconate.

Animals↗
PubMed1987

Ulcer pain mechanisms. The clinical features of active peptic ulcer disease and implications for therapy.

Pain is commonly the initial symptom in peptic ulcer, but the mechanism is controversial. Chemical irritation by hydrochloric acid (HCl) and disordered motor activity have been implicated. Questions have been raised as to whether pain is a good indicator of an active ulcer. We have studied the mechanism of ulcer pain, using intragastric administration of 0.1 N HCl, study of X-ray alterations, measurement of intraluminal pressures, and measurement of gastric acidity along with fluorocinematography. Ulcer pain was accompanied by a synchronous increase in motor activity; gastric emptying was rapid with duodenal ulcer and delayed with gastric ulcer; relief of pain occurred with emptying. Ulcer pain is not a good indicator of activity. Relief of ulcer pain before endoscopic healing with famotidine is due to the inhibition of HCl below the threshold required to initiate disturbances of motor activity. Recurrent 'silent' ulcer with complications occurs in 40% of patients.

Fluoroscopy↗
PubMed1975

Bile aspiration: an experimental study in rabbits.

It has been shown that bile injected intratracheally in rabbits produces severe pulmonary edema, atelectasis, and focal hemorrhages. The authors investigated the effect of a number of solutions, including physiological concentration of bile, hydrochloric acid pH 1.0, bile salt diluted to 1%, and bile at 100% concentrations. Whenever the bile concentration exceeded 3%, none of the test animals survived. It is not possible to apply directly the results of an experimental animal study to humans. However, the severity of the pulmonary changes produced force the conclusion that bile is a potentially dangerous aspirate in humans.

Animals↗
PubMed1988

[Utilization of modified waste from the antibiotic industry for the production of construction materials].

Possible utilization of treated streptomycin fermentation broth modified with waste hydrochloric acid solution followed by lime neutralization was studied. Such a complex additive to concrete increased its strength by 36-41 per cent. With saving cement by 7 per cent the concrete strength increased by 22-29 per cent as compared to the control samples. Therefore, utilization of antibiotic industry waste in production of building material allowed not only to improve its quality but also to lower the environmental pollution.

Acetates↗
PubMed1987

Cation dependence of frog gustatory neural responses to acid stimuli.

1. To understand the mechanism underlying the gustatory response for acid stimuli, the characteristics of glossopharyngeal neural responses elicited by 1 mM hydrochloric acid (HCl) in bullfrogs were examined by changing the ionic composition of adapting solutions flowed on the tongue surface. 2. The amplitude of the gustatory neural response for HCl was increased with an increase of Ca2+ concentration in the adapting solution. 3. The action of Ca2+ in the adapting solution could be replaced by Ba2+ and Sr2+, and was inhibited by Co2+, suggesting that the Ca2+ channel in the receptor membrane of taste cells is related to a gustatory neural response to acid.

Acclimatization↗
PubMed1997

Analysis of monosaccharide composition by capillary electrophoresis.

The monosaccharide composition analysis described in this paper employs capillary electrophoretic separation of sugar monomers liberated from glycoproteins or oligosaccharides, by high temperature acidic hydrolysis. Trifluoroacetic acid was used for sialo- and neutral-sugar hydrolysis, and hydrochloric acid was used for amino-sugar hydrolysis. The neutral- and amino-sugars in the hydrolyzates were then labeled with a charged fluorophore, 8-aminopyrene-1,3,6-trisulfonate, while sialic acids were labeled with 9-aminoacridone. The stoichiometry of labeling was such that only one fluorophore molecule was attached to each monosaccharide molecule. The labeled monosaccharides were then separated by high-performance capillary electrophoresis with laser induced fluorescence detection. The acidic hydrolysis and fluorophore labeling conditions described in this paper are suitable for monosaccharide composition analysis of a wide variety of complex carbohydrates from glycoprotein and/or oligosaccharide samples using capillary electrophoresis.

Acetylglucosamine↗
PubMed2001

Listed chemicals; establishment of non-regulated transactions in anhydrous hydrogen chloride. Final rule confirmation.

Effective October 3, 1996, the Comprehensive Methamphetamine Control Act of 1996 (MCA) had the practical effect of directing the DEA to place domestic controls on anhydrous hydrogen chloride. Previously, exports of the listed chemical hydrochloric acid (including anhydrous hydrogen chloride, referred to in the MCA as hydrochloric gas, which is a form of hydrogen chloride) were already regulated pursuant to 21 CFR 1310. A domestic threshold of zero (0.0 kilograms) for anhydrous hydrogen chloride became effective September 1,2000, by a Final Rule published on August 2, 2000 (65 FR 47309). Although the threshold for anhydrous hydrogen chloride is established at 0.0 kilogram, DEA has concluded that certain transactions in anhydrous hydrogen chloride are not sources for diversion. The Final Rule establishing a zero threshold for anhydrous hydrogen chloride also provided exemption, on an interim basis, from the recordkeeping and reporting requirements for: (1) Domestic transactions involving pipeline distributions; and (2) domestic distributions of 12,000 pounds (net weight) or more in a single container. Because these exemptions were not discussed in the Notice of Proposed Rulemaking published on September 30,1997 (62 FR 51072), DEA requested public comment with respect to the exemption for these two types of transactions involving anhydrous hydrogen chloride. The period for public comment closed on September 1, 2000. Two comments were received supporting these exemptions. This publication finalizes the interim rule without change.

Central Nervous System Stimulants↗
PubMed1994

Characterization of air contaminants formed by the interaction of lava and sea water.

We made environmental measurements to characterize contaminants generated when basaltic lava from Hawaii's Kilauea volcano enters sea water. This interaction of lava with sea water produces large clouds of mist (LAZE). Island winds occasionally directed the LAZE toward the adjacent village of Kalapana and the Hawaii Volcanos National Park, creating health concerns. Environmental samples were taken to measure airborne concentrations of respirable dust, crystalline silica and other mineral compounds, fibers, trace metals, inorganic acids, and organic and inorganic gases. The LAZE contained quantifiable concentrations of hydrochloric acid (HCl) and hydrofluoric acid (HF); HCl was predominant. HCl and HF concentrations were highest in dense plumes of LAZE near the sea. The HCl concentration at this sampling location averaged 7.1 ppm; this exceeds the current occupational exposure ceiling of 5 ppm. HF was detected in nearly half the samples, but all concentrations were <1 ppm Sulfur dioxide was detected in one of four short-term indicator tube samples at approximately 1.5 ppm. Airborne particulates were composed largely of chloride salts (predominantly sodium chloride). Crystalline silica concentrations were below detectable limits, less than approximately 0.03 mg/m3 of air. Settled dust samples showed a predominance of glass flakes and glass fibers. Airborne fibers were detected at quantifiable levels in 1 of 11 samples. These fibers were composed largely of hydrated calcium sulfate. These findings suggest that individuals should avoid concentrated plumes of LAZE near its origin to prevent over exposure to inorganic acids, specifically HCl.

Air Pollutants↗
PubMed1986

Selective oxidation and reduction of methionine residues in peptides and proteins by oxygen exchange between sulfoxide and sulfide.

Treatment of amino acids, peptides, and proteins with aqueous solution of dimethyl sulfoxide (Me2SO) and hydrochloric acid (HCl) resulted in the oxidation of methionine to methionine sulfoxide. In addition to methionine, SH groups are also oxidized, but this reaction proceeds after a lag period of 2 h. Other amino acids are not modified by aqueous Me2SO/HCl. The reaction is strongly pH-dependent. Optimal conditions are 1.0 M HCl, 0.1 M Me2SO, at 22 degrees C. The reaction exhibits pseudo-first order kinetics with Kobs = 0.23 +/- 0.015 M-1 min-1 at 22 degrees C. Incubation of methionine sulfoxide with dimethyl sulfide and HCl resulted in the conversion of methionine sulfoxide to methionine. This reaction is fast (t1/2 = 4 min at room temperature) and quantitative at relatively anhydrous condition (i.e. at H2O:concentrated HCl:dimethyl sulfide ratio of 2:20:1). Quantitative conversions of methionine sulfoxide back to methionine are obtained in peptides and proteins as well, with no observable other side reactions in amino acids and proteins. The wide applications of this selective oxidation and reduction of methionine residues are demonstrated and discussed.

Adrenocorticotropic Hormone↗
PubMed2000

[Pretreatment of acid-induced lung injury with specific neutrophil elastase inhibitor ONO-5046 did not exasperate the subsequent bacterial lung infection by Pseudomonas aeruginosa].

Patients with acid lung injuries are at high risk for bacterial pulmonary infections which commonly occur several days after the acid aspiration. We reported that a specific neutrophil elastase inhibitor ONO-5046 inhibited the multi-organ injury caused by acid-instillation into the lung. In this study, we evaluated the effect of ONO-5046 on lung infection by Pseudomonas aeruginosa (PAO-1:Ps.) following acid-induced lung injury in rat lungs. Animals received 0.2 ml of hydrochloric acid (pH = 1) into the right lungs. Pretreated animals were administered ONO-5046 (30 mg.kg-1) i.v. 15 min. before acid instillation. Other groups received vehicle (saline). Twenty four hours later, they were instilled with 0.1 ml of Ps. 1 x 10(8) cfu into the left lungs. Four hours after bacterial challenge, the animals were deeply anesthetized and killed. Bronchoalveolar lavage was done on each lung separately to evaluate neutrophil elastase activity, neutrophil number and protein permeability of lung endothelium and epithelium. The numbers of Ps. in the lungs were measured. In the Ps.-instilled lung, the number of Ps. or the protein permeability was not increased with ONO-5046 pretreatment compared with those in the untreated group. Pretreatment inhibited the exasperation of the protein permeability indirectly caused by Ps. infection in the acid-instilled lung. It was indicated that ONO-5046 could inhibit the indirect lung injury caused by acid-instillation into the lung without aggravating the subsequent bacterial infection.

Animals↗
PubMed1990

Is gastric acid responsible for the pain in patients with essential dyspepsia?

The pathogenesis of symptoms in patients with essential dyspepsia is not known. Since treatment with H2-receptor antagonists has provided symptomatic relief in some reports, we carried out the present study to investigate whether gastric acid is responsible for symptoms in these patients. Fifty patients with essential dyspepsia and 25 healthy control subjects were studied. After an overnight fast, a nasogastric tube was passed and its tip positioned in the antrum under fluoroscopic control. Normal saline or 0.1 M hydrochloric acid was infused in a randomized, double-blind fashion. Eleven (22%) patients developed pain with acid infusion, but none with normal saline (p less than 0.005). In 10 of these 11 patients, pain recurred on rechallenge with acid infusion but was promptly relieved with infusion of 1 M sodium bicarbonate. None of the healthy controls developed pain on infusion of acid or saline. These observations suggest that acid has a definite role in the pathogenesis of symptoms in some patients with essential dyspepsia, although other factors may also be important.

Adolescent↗
PubMed1986

Esophageal blood flow in the cat. Normal distribution and effects of acid perfusion.

The radioactive microsphere technique was used to estimate blood flow to different regions of the esophagus and to adjacent regions of the stomach before and after perfusion of the esophagus with hydrochloric acid (pH 1.5) for 5 min. Under resting conditions total blood flow, as well as blood flow to the mucosal-submucosal layer and the muscular layer, to both sphincters was significantly higher than to the esophageal body. Blood flow to the adjacent regions of the stomach was significantly higher than esophageal blood flow. Acid perfusion resulted in a large increase in total blood flow in both sphincters and the lower esophageal body. Gastric blood flow was not altered by acid perfusion. The esophageal hyperemia resulted primarily from an increase in blood flow to the muscular layer; mucosal-submucosal blood flow was increased only in the lower esophageal sphincter. The present study indicates that short periods (5 min) of gastroesophageal reflux may increase esophageal blood flow.

Animals↗
PubMed1980

The effect of ascorbic acid on experimental acid burns of the rabbit cornea.

The corneas of albino rabbits were subjected to 45 sec, 12 mm, 2.3N hydrochloric acid burns. Of 18 eyes in nine rabbits receiving no treatment (controls), 11 (61%) developed ulceration sometimes progressing to descemetoceles and perforation. Of 17 eyes in nine rabbits receiving a daily subcutaneous injection of ascorbic acid (0.5 gm/kg), only one eye (5.9%) developed an anterior stromal ulcer. The difference in incidence of ulceration between the control and ascorbate-treated eyes was statistically significant (p less than 0.01). The aqueous humor level of ascorbate in untreated animals was 6.0 +/- 0.6 mg/dl compared to 33.0 +/- 2.7 in the treated group. This study therefore demonstrates that subcutaneous administration of ascorbic acid significantly raises the aqueous humor level of ascorbic acid in severely acid-burned eyes, thereby largely preventing the characteristic development of corneal ulceration. The mechanism of this effect is presumably the same as previously described for alkali-burned eyes.

Animals↗