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PubMed1990

Effect of insulin on the utilization of propionate in gluconeogenesis in sheep.

The effects of insulin on the utilization of propionate in glucose synthesis were studied in fed and fasted sheep. Insulin was infused at 0.40 microU/h into the mesenteric vein. Glucose was infused to prevent hypoglycaemia. The rate of incorporation of [2-14C]propionate into glucose was determined before and during insulin infusion. After 150 min of insulin infusion endogenous glucose synthesis was about 70% of control values, whereas the incorporation of [14C]propionate into plasma glucose was 94% of control values. In contrast, the incorporation of other glucose precursors into glucose was decreased 30-50% by insulin. Therefore, insulin does not appear to decrease the utilization of propionate in gluconeogenesis. These results are consistent with the proposition that insulin differentially affects the rate of incorporation of glucose precursors into glucose in ruminant animals.

Animals↗

PubMed1993

Responses in the voluntary intake of hay or silage by lactating cows to intraruminal infusions of sodium acetate or sodium propionate, the tonicity of rumen fluid or rumen distension.

Rumen-fistulated lactating cows were individually fed on hay or silage and intakes were monitored during 3 h treatment periods and for 2 h after. Each experiment used five, six or seven animals and the treatments were applied in a Latin Square design. Sodium acetate infusions of 1.8-11.0 mol in 4.5 litres water caused a dose-related depression in hay intake, the extent being 82 g dry matter (DM)/mol infused (P < 0.01). Sodium acetate infusions of 6.0-15.0 mol in 4.5 litres water caused a dose-related depression in silage intake of 118 g DM/mol infused. Rumen fluid pH for both diets was unaffected by treatment. Acetate and Na concentrations were increased and significantly negatively correlated with intake of both diets. Infusions of 2-8 mol sodium propionate caused a dose-related depression of hay intake which was significant when cow and day effects were accounted for. Sodium propionate infusions of 4-8 mol significantly depressed silage intake by 140 g DM/mol infused (P < 0.001). Rumen fluid pH was unaffected by treatment while propionate and Na concentrations were elevated and significantly negatively correlated with intake for both diets. Inflation of a rubber balloon in the rumen with 12.5-20 litres warm water resulted in a dose-dependent depression in hay intake of 66 g DM/l distension (P < 0.05). There was significant overeating during the 2 h following the 20 litre treatment. With silage, 15-25 litres of balloon distension for 3 h resulted in a dose-dependent depression in intake of 28 g DM/l distension (P < 0.001). There was no significant overeating during the 2 h following distension. When given in physiological amounts, at the lower end of the range used in these experiments, acetate, propionate and distension of the rumen did not significantly affect hay intakes. However, in each case the linear relationship between intake depression and level of treatment suggested that these factors could contribute to the control of feed intake.

Acetates↗

PubMed1995

Effects of dietary propionate on hepatic glucose production, whole-body glucose utilization, carbohydrate and lipid metabolism in normal rats.

Increased intake of dietary fibres is associated with several beneficial effects on carbohydrate and lipid metabolism. The colonic fermentation of dietary fibres produces short-chain fatty acids (SCFA; acetate, propionate and butyrate). Some authors have suggested that SCFA could be partly responsible for the effects of dietary fibres. The purpose of the present study was to test the effects of one of the SCFA, propionate. The effects of moderate amounts of dietary propionate on insulin sensitivity and hepatic glucose production were studied in male Sprague-Dawley rats. Two groups of twenty-one adult rats were fed for 3 weeks on a diet containing 78 g propionate/kg (P) or 78 g/kg of a poorly fermentable cellulose (control group; C). Feed intake, body weight, fasting plasma glucose, insulin, free fatty acids, alanine, lactate, glycerol and beta-hydroxybutyrate levels were measured weekly in anaesthetized rats. At the end of the feeding period basal hepatic glucose production (BHGP) was measured with a primed continuous infusion of [3-3H]glucose and the in vivo insulin sensitivity in rats was quantified by the euglycaemic-hyperinsulinaemic clamp technique (0.6 and 2 U/kg per h). At that time fasting plasma glucose measured in anaesthetized rats was significantly lower in group P than in group C: 7.7 (SE 0.2) v. 8.5 (SE 0.2) mmol/l respectively (P < 0.002); plasma insulin levels were not significantly different. Neither the BHGP (mg/min per kg; C 14.8 (SE 1.3), P 15.1 (SE 1.3); n 7, not significant) nor the basal metabolic clearance (ml/min per kg; 8.9 (SE 0.8) v. 9.9 (SE 1.1); not significant) were different between treatments. Hepatic glucose production and glucose utilization at the two insulin concentrations (approximately 500 and 1500 mU/l respectively, n 7) did not differ significantly between the two groups. These results show that dietary propionate chronically ingested by normal rats could decrease fasting glycaemia, but from our findings, no effect on hepatic glucose production and whole-body glucose utilization could be clearly demonstrated.

Animals↗

PubMed1981

[Propionic acid preservation of corn following inoculation with molds and yeasts].

In laboratory tests spores of 7 Fusarium species, 6 yeast species, and of the molds Paecilomyces varioti and Trichoderma viride were inoculated into propionic acid treated corn. The initial moisture content of the corn was adjusted to 19, 25, 32, and 40%, the propionic acid dosages being 0.3, 0.5, 0.7, and 1.0% respectively. By these treatments the growth of the inoculated fungi was inhibited for a storage of a least 6 months at 20 degrees C. The inhibition of growth was indicated by the decrease of viable mold count, the percentage of surface-sterilized kernels infected with fungi being 0% after 6 months. In addition, by the propionic acid treatment the production of zearalenone by two strains of Fus. culmorum and three strains of Fus. graminearum, and the production of T-2 toxin by two strains of Fus. tricinctum and one strain of Fus. sporotrichioides was inhibited. These results were obtained during an incubation period of 1-4 months using a temperature shift (20 and 10 degrees C). The propionic-acid dosage sufficient for the inhibition of the inoculated fungi was lower than that recommended in the literature for large-scale treatment of corn.

Food Microbiology↗

PubMed1983

Changes of glucose, insulin and glucagon associated with propionate infusion and vitamin B-12 status in sheep.

The effect of propionate on hormonal and metabolic events was studied in ewes that were vitamin B-12 depleted (de-B12) and repleted (re-B12). Experiments were conducted before and after hydroxocobalamin resupplementation. De-B12 sheep had greater blood concentrations and total hepatic influx and efflux of glucose. However, rates of net hepatic release of glucose were similar. Comparable glucagon concentrations and fluxes were reduced in de-B12, but insulin values were unaffected by vitamin B-12 status. Intramesenteric infusion of propionate elevated concentrations of glucose, insulin and glucagon at nearly all samplings. Secretion of insulin was elevated at the first sampling only (15 minutes), while glucagon appeared elevated until 30 minutes. Rates of hepatic removal of hormones were not altered during infusion. Net hepatic release of glucose was increased at nearly all samplings, but de-B12 ewes had a greater increment of total hepatic influx and efflux. De-B12 ewes exhibited a diminished glucagon response to propionate infusion, whereas insulin concentrations and hepatic uptakes tended to be greater. Vitamin B-12 status, within the range usually considered normal, thus influences metabolic and hormonal responses to increased rates of propionate entry in the sheep, independent of feed intake.

Animals↗

PubMed1996

Serum acetate:propionate ratio is related to serum cholesterol in men but not women.

Acetic and propionic acids, produced by colonic fermentation of unabsorbed carbohydrates, may influence systemic lipid metabolism. To determine whether the ratio of the concentrations of acetate to propionate in peripheral serum of fasting humans was related to serum cholesterol, we studied 62 men [age 45 +/- 17 y (mean +/- SD), range 19-74 y; body mass index 25.0 +/- 2.8 kg/m2] and 69 women [43 +/- 18 y, (range, 18-77 y); body mass index 23.0 +/- 3.1 kg/m2] with normal serum lipid concentrations. The concentrations of serum acetate, propionate and butyrate (means +/- SD) were similar in men (98 +/- 33, 3.8 +/- 1.5 and 2.3 +/- 1.5 micromol/L, respectively) and women (92 +/- 38, 3.9 +/- 1.9 and 2.3 +/- 1.6 micromol/L). There were significant positive relationships between the serum acetate:propionate ratio and total cholesterol (r = 0.466, P = 0.0002) and LDL cholesterol (r = 0.384, P = 0.0023) in men, but in women the relationships were not significant (R = 0.174, P = 0.15 and r = 0.135, P = 0.27, respectively). The relationships in men remained significant after adjustment for age and body mass index. These data support the hypothesis that, at least in men, colonic short-chain fatty acids influence systemic lipid metabolism. The relationships among the factors influencing colonic short-chain fatty acid production, the enterohepatic circulation of endogenous estrogens, dietary phytoestrogens and blood lipids in women, however, need further clarification.

Acetates↗

PubMed2001

Butyrate and propionate downregulate ERK phosphorylation in HT-29 colon carcinoma cells prior to differentiation.

We have characterized the effects of different short-chain fatty acids (SCFAs) on cell growth and differentiation as well as the phosphorylation state of ERK1 and 2 in the human colon adenocarcinoma cell line HT-29. Of the five SCFAs tested, only butyrate and propionate impaired cellular proliferation. Moreover, butyrate and propionate specifically resulted in a decrease in ERK1 and 2 phosphorylation at 3 and 6 hours post-treatment, suggesting a correlation between the ability of these SCFAs to inhibit cellular proliferation and decrease ERK phosphorylation. Notably, the decrease in ERK phosphorylation was observed prior to the induction of the differentiation markers alkaline phosphatase (AP) and carcinoembryonic antigen (CEA) by butyrate and propionate from days 6 to 18 post-treatment. In the case of butyrate- and propionate-induced differentiation, ERK phosphorylation is a marker and may play a role in the proliferation and/or differentiation states of this cell line.

Alkaline Phosphatase↗

PubMed2001

Desulfomusa hansenii gen. nov., sp. nov., a novel marine propionate-degrading, sulfate-reducing bacterium isolated from Zostera marina roots.

The physiology and phylogeny of a novel sulfate-reducing bacterium, isolated from surface-sterilized roots of the marine macrophyte Zostera marina, are presented. The strain, designated P1T, was enriched and isolated in defined oxygen-free, bicarbonate-buffered, iron-reduced seawater medium with propionate as sole carbon source and electron donor and sulfate as electron acceptor. Strain P1T had a rod-shaped, slightly curved cell morphology and was motile by means of a single polar flagellum. Cells generally aggregated in clumps throughout the growth phase. High CaCl2 (10 mM) and MgCl2 (50 mM) concentrations were required for optimum growth. In addition to propionate, strain P1T utilized fumarate, succinate, pyruvate, ethanol, butanol and alanine. Oxidation of propionate was incomplete and acetate was formed in stoichiometric amounts. Strain P1T thus resembles members of the sulfate-reducing genera Desulfobulbus and Desulforhopalus, which both oxidize propionate incompletely and form acetate in addition to CO2. However, sequence analysis of the small-subunit rDNA and the dissimilatory sulfite reductase gene revealed that strain P1T was unrelated to the incomplete oxidizers Desulfobulbus and Desulforhopalus and that it constitutes a novel lineage affiliated with the genera Desulfococcus, Desulfosarcina, Desulfonema and 'Desulfobotulus'. Members of this branch, with the exception of 'Desulfobotulus sapovorans', oxidize a variety of substrates completely to CO2. Strain P1T (= DSM 12642T = ATCC 700811T) is therefore proposed as Desulfomusa hansenii gen. nov., sp. nov. Strain p1T thus illustrates the difficulty of extrapolating rRNA similarities to physiology and/or ecological function.

Biodegradation, Environmental↗

PubMed2002

Desulfotomaculum thermobenzoicum subsp. thermosyntrophicum subsp. nov., a thermophilic, syntrophic, propionate-oxidizing, spore-forming bacterium.

From granular sludge from a laboratory-scale upflow anaerobic sludge bed reactor operated at 55 degrees C with a mixture of volatile fatty acids as feed, a novel anaerobic, moderately thermophilic, syntrophic, spore-forming bacterium, strain TPO, was enriched on propionate in co-culture with Methanobacterium thermoautotrophicum Z245. The axenic culture was obtained by using pyruvate as the sole source of carbon and energy. The cells were straight rods with pointed ends and became lens-shaped when sporulation started. The cells were slightly motile. The optimum growth temperature was 55 degrees C and growth was possible between 45 and 62 degrees C. The pH range for growth of strain TPO was 6-8, with an optimum at pH 7-7.5. Propionate was converted to acetate, CO2 and CH4 by a co-culture of strain TPO with Methanobacterium thermoautotrophicum Z245. In pure culture, strain TPO could grow fermentatively on benzoate, fumarate, H2/CO2, pyruvate and lactate. Sulphate could serve as inorganic electron acceptor when strain TPO was grown on propionate, lactate, pyruvate and H2/CO2. The G+C content was 53.7 mol%. Comparison of 16S rDNA sequences revealed that strain TPO is related to Desulfotomaculum thermobenzoicum (98%) and Desulfotomaculum thermoacetoxidans (98%). DNA-DNA hybridization revealed 88.2% reassociation between strain TPO and D. thermobenzoicum and 83.8% between strain TPO and D. thermoacetoxidans. However, both organisms differ physiologically from strain TPO and are not capable of syntrophic propionate oxidation. It is proposed that strain TPO should be classified as new subspecies of D. thermobenzoicum as D. thermobenzoicum subsp. thermosyntrophicum.

Anaerobiosis↗

PubMed2003

Propionicimonas paludicola gen. nov., sp. nov., a novel facultatively anaerobic, Gram-positive, propionate-producing bacterium isolated from plant residue in irrigated rice-field soil.

Two propionate-producing strains (Wd(T) and Wf) that were isolated anaerobically from plant residue of irrigated rice-field soil in Japan were characterized phenotypically and phylogenetically. The growth rate of strain Wd(T) was very slow in basal medium, but both growth and propionate production were stimulated significantly by the addition of cyanocobalamin. Strain Wf grew well in basal medium and produced substantial amounts of fermentation products, including propionate. Other phenotypic and phylogenetic characteristics of the two isolates were almost identical. Both were facultatively anaerobic, but much better growth was observed under anaerobic conditions. Cells were Gram-positive, non-motile, non-spore-forming and pleomorphic rods with irregular V- or crescent-shaped cell arrangements. Fermentation products from glucose in the presence of excess cyanocobalamin were acetate, lactate, a small amount of succinate and CO(2), in addition to propionate. Both oxidase and catalase activities were negative. The strains possessed meso-diaminopimelic acid in their peptidoglycan and their major cellular fatty acids were C(13 : 0), anteiso-C(15 : 0) and C(15 : 0). The isolates had high genomic DNA G+C contents (68.7 and 67.4 mol%, respectively). Menaquinones MK-9(H(4)) and MK-10(H(4)) were the predominant respiratory quinones. Phylogenetic analysis based on 16S rDNA sequences placed both strains in the Actinobacteria, with Micropruina glycogenica as their closest relative (sequence similarity values of 95.8 and 95.7 %, respectively). Microlunatus phosphovorus and Friedmanniella antarctica were also related closely to the isolates. As their morphological, physiological and chemotaxonomic characteristics were distinctly different from those of any related species, Propionicimonas paludicola gen. nov., sp. nov. is proposed to accommodate these strains. The type strain of the novel species is Wd(T) (=JCM 11933(T)=DSM 15597(T)).

Actinomycetales↗

PubMed2005

The first true obligately syntrophic propionate-oxidizing bacterium, Pelotomaculum schinkii sp. nov., co-cultured with Methanospirillum hungatei, and emended description of the genus Pelotomaculum.

A Gram-positive, spore-forming, syntrophic propionate-oxidizing bacterium, Pelotomaculum schinkii sp. nov. strain HH(T), was isolated as a co-culture with Methanospirillum hungatei JF-1(T) from anaerobic, freeze-dried granular sludge obtained from an upflow anaerobic sludge bed reactor treating sugar beet wastewater. The bacterium converted propionate to acetate in co-culture with Methanospirillum hungatei JF-1(T) or Methanobacterium formicicum MF(NT), but not in co-culture with Methanobrevibacter arboriphilus AZ. The organism could not be cultured axenically with any of the substrates tested and therefore can be considered as a (the first) true anaerobic syntrophic bacterium. The bacterium contained two distinct 16S rRNA gene sequences, with 96.8% sequence similarity, which were both expressed during syntrophic growth on propionate as revealed by fluorescent in situ hybridization. The most closely related organisms are Cryptanaerobacter phenolicus LR7.2(T), a bacterium that transforms phenol into benzoate, and Pelotomaculum thermopropionicum SI(T), a thermophilic, syntrophic propionate-oxidizing bacterium. Other related species belong to the Gram-positive, sulfate-reducing genus Desulfotomaculum. The type strain of Pelotomaculum schinkii is strain HH(T) (=ATCC BAA-615(T)=DSM 15200(T)).

Anaerobiosis↗

PubMed2004

2-Methylcitrate-dependent activation of the propionate catabolic operon (prpBCDE) of Salmonella enterica by the PrpR protein.

The function of the PrpR protein of Salmonella enterica serovar Typhimurium LT2 was studied in vitro and in vivo. The PrpR protein is a sensor of 2-methylcitrate (2-MC), an intermediate of the 2-methylcitric acid cycle used by this bacterium to convert propionate to pyruvate. PrpR was unresponsive to citrate (a close structural analogue of 2-MC) and to propionate, suggesting that 2-MC, not propionate, is the metabolite that signals the presence of propionate in the environment to S. enterica. prpR alleles encoding mutant proteins with various levels of 2-MC-independent activity were isolated. All lesions causing constitutive PrpR activity were mapped to the N-terminal domain of the protein. Removal of the entire sensing domain resulted in a protein (PrpR(c)) with the highest 2-MC-independent activity. Residue A162 is critical to 2-MC sensing, since the mutant PrpR protein PrpR(A162T) was as active as the PrpR(c) protein in the absence of 2-MC. DNA footprinting studies identified the site in the region between prpR and the prpBCDE operon to which the PrpR protein binds. Analysis of the binding-site sequence revealed two sites with dyad symmetry. Results from DNase I footprinting assays suggested that the PrpR protein may have higher affinity for the site proximal to the P(prpBCDE) promoter.

Adaptation, Physiological↗

PubMed1994

Cutaneous manifestations of methylmalonic and propionic acidaemia: a description based on 38 cases.

Methylmalonic and propionic acidaemias are rare metabolic disorders with an autosomal recessive mode of inheritance. A number of aminoacidopathies may have cutaneous manifestations, but these are usually absent in methylmalonic and propionic acidaemia. We have studied 38 children with propionic and methylmalonic acidaemia in the last 10 years at the Hôpital Necker-Enfants Malades. Thirteen had cutaneous manifestations: acute superficial scalded skin and superficial desquamation, bilateral and periorificial dermatitis, psoriasiform eruptions, and alopecia. The relative uniformity of these manifestations (scalded skin and desquamation after metabolic decompensation, chronic bilateral and periorificial dermatitis) suggests that methylmalonic and propionic acidaemias should be included in the category of aminoacidopathies with cutaneous manifestations. All these patients were suffering from severe forms of these diseases, with no residual enzyme activity, and they were all subjected to a very severe natural protein-restricted diet. These cutaneous manifestations may therefore either be part of a complex multideficiency syndrome, or be due to the enzyme deficiency itself.

Amino Acid Metabolism, Inborn Errors↗

PubMed1996

Metabolic activities of Listeria monocytogenes in the presence of sodium propionate, acetate, lactate and citrate.

The effects of sodium propionate, acetate, lactate and citrate on cell proliferation, glucose and oxygen consumption, and ATP production in Listeria monocytogenes were investigated in growing and resting cells. Media pH was 6.7-6.8. Growth inhibition increased while glucose consumption continued in the presence of > or = 1% propionate, > or = 3% acetate and > or = 5% lactate in broth during incubation at 35 degrees C, indicating that glucose consumption was uncoupled from cell proliferation. Acetate and propionate were the most effective antilisterials, whereas citrate (5%) was only slightly inhibitory. Of the four salts, only lactate supported growth, oxygen consumption and ATP production. While concentrations of 1 and 5% propionate, acetate and citrate did not have an effect on oxygen consumption, they inhibited ATP production. ATP production in the presence of the four salts was consistently lower at pH 6.0 than at neutral pH. Lactate served as an alternative energy source for L. monocytogenes in the absence of glucose but became toxic to the organism in the presence of the carbohydrate.

Adenosine Triphosphate↗

PubMed1996

Identification of a new prp locus required for propionate catabolism in Salmonella typhimurium LT2.

A new propionate (prp) locus of S. typhimurium was defined by mutation, was located to minute 8 of the chromosome, and was shown to be transcribed in the clockwise direction. A plasmid carrying the wild-type prp+ locus was isolated by complementation and its initial physical characterization is presented. Transcriptional regulation of prp was studied using MudI1734(lacZ+) operon fusions. Propionate stimulated prp transcription in a merodiploid strain containing prp+ and a prp::MudI1734 fusion, but failed to stimulate transcription of the same fusion in a haploid genetic background. prp transcription was reduced by a factor of 2 in strains deficient in the synthesis of the global regulatory protein FruR; fruR mutants failed to grow on propionate. Propionate blocked growth of prp mutants on medium containing succinate as carbon/energy source.

Chromosome Mapping↗

PubMed2006

Butyrate- and propionate-degrading syntrophs from permanently cold marine sediments in Skan Bay, Alaska, and description of Algorimarina butyrica gen. nov., sp. nov.

Two anaerobic, psychrotolerant, syntrophic strains were enriched from permanently cold, shallow anoxic marine sediments in Skan Bay, Alaska. One strain, AK-B(T), oxidized butyrate syntrophically and was isolated in defined coculture with a H(2)-using methanogen or in a dixenic coculture that also contained an acetate-scavenging methanogen. The other enrichment culture syntrophically oxidized propionate. The growth of these syntrophic cultures was very slow: approximately 1 year for cocultures of strain AK-B(T) to form colonies and >1 year for the propionate-oxidizing enrichment to form colonies. Neither culture grew axenically when supplied with the catabolic substrates crotonate, pyruvate, malate, or sulfate plus butyrate or propionate. Strain AK-B(T) catabolized iso-butyrate in syntrophic coculture but did not catabolize valerate or caproate. Phylogenetic analyses of the 16S rRNA gene sequence suggested that strain AK-B(T) was only distantly related to cultivated sulfate-reducing bacteria, and that this strain represented a new genus. We propose Algorimarina butyrica, with strain AK-B(T) (=OCM 842(T)), as the type strain. This report is the first description of psychrotolerant as well as marine butyrate--and propionate-oxidizing syntrophic organisms.

Alaska↗

PubMed1999

Propionate and butyrate esters of camptothecin and 9-nitrocamptothecin as antileukemia prodrugs in vitro.

Six camptothecin (CPT) alkyl esters and four 9-nitrocamptothecin (9NC) alkyl esters were assayed for ability to inhibit proliferation and induce programmed cell death (apoptosis) in human leukemia HL-60 and U-937 cells, which exhibit differential sensitivity to CPT and 9NC. In general, CPT-propionate and CPT-butyrate demonstrated activities, while the other esters were practically inactive. Similarly, 9NC-propionate and 9NC-butyrate were active, while the other 9NC esters exhibited little or no activity. The biologically active esters required metabolic conversion (i.e., de-esterification) to their parental compounds as demonstrated by the conversion of CPT-propionate to CPT in mouse liver homogenate, and the topoisomerase I-inhibition assay. In conclusion, the propionate and butyrate esters of CPT and 9NC are CPT and 9NC prodrugs, that can develop to important chemotherapeutic agents for the effective treatment of human leukemias and other malignancies.

Animals↗

PubMed1994

Functional role of bicarbonate in propionate transport across guinea-pig isolated caecum and proximal colon.

1. Unidirectional fluxes of propionate across isolated epithelia from the guinea-pig caecum and proximal colon were measured under short-circuit current conditions. In the caecum and proximal colon the serosal-to-mucosal propionate flux (JPrsm) was higher than mucosal-to-serosal flux (JPrms), resulting in a net secretory flux of propionate. 2. HCO3(-)-CO2-free solution reduced JPrms in the caecum and proximal colon markedly; JPrsm was not (caecum) or little (proximal colon) affected. The subsequent addition of acetazolamide caused a further decrease in JPrms in the proximal colon, but not in the caecum. 3. In HCO3(-)-containing solutions acetazolamide or ethoxzolamide inhibited JPrms; JPrsm was not affected. A macromolecular carbonic anhydrase inhibitor, prontosil-dextran, had no effect on propionate fluxes, indicating that the intracellular carbonic anhydrase is of importance for short-chain fatty acid transport. 4. Subsequent to carbonic anhydrase inhibition, mucosal addition of amiloride caused a slight further decrease of JPrms in the caecum and proximal colon; JPrsm was not affected. 5. Results support the view that a considerable proportion of short-chain fatty acids (SCFAs) is absorbed via a SCFA(-)-HCO3- exchange.

Acetazolamide↗