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A M Batlle

Publications and source records attributed to A M Batlle.

At least 37 records · Page 2Linked to original sources
PubMed1996

Strain and sex differences in the effect of enflurane and isoflurane on heme metabolism in mice.

1. The influence of strain and sex on the effect of enflurane and isoflurane and administration on heme metabolism was investigated to identify the animal model which could best reproduce the biochemical signs of acute intermittent porphyria. 2. Enflurane produced 35% and 80% increases in ALA-S activity only in CF1 male and female mice, respectively, whereas isoflurane induced 40% enzyme activity in CF1 male. 3. CF1 males showed around 35% decrease in blood PBGase and PBG-deaminase after administration of enflurane, whereas isoflurane provoked a striking inhibition (70%) in males of the C57 strain. 4. Enflurane produced alterations in heme synthesis, which would fit a model of acute porphyria in CF1 male mice. On the other hand, isoflurane would mimic biochemical alterations of this porphyria in C57 males.

5-Aminolevulinate Synthetase↗
PubMed1995

STZ-induced diabetes in mice and heme pathway enzymes. Effect of allylisopropylacetamide and alpha-tocopherol.

A frequent coexistence of diabetes and porphyria disease has been reported. Under normal conditions, porphyrin biosynthesis is well regulated to only form the amount of heme required for the synthesis of the various hemoproteins. The activity of some heme enzymes and rhodanese in streptozotocin (STZ) induced diabetic mice and in allylisopropylacetamide (AIA) induced experimental acute porphyria mice has been examined. The role of alpha-tocopherol (alpha-T), reported to prevent protein glycation in vitro, has also been investigated. AIA induced hepatic delta-aminolevulinic acid synthetase (ALA-S) activity in control animals but was ineffective in the diabetic group. alpha-Tocopherol did not modify ALA-S activity in either group. delta-Aminolevulinic acid dehydratase (ALA-D) and deaminase activities were significantly diminished both in liver and blood of diabetic animals. alpha-Tocopherol prevented inhibition of ALA-D, deaminase and blood rhodanese activities in diabetic animals but alpha-tocopherol by itself did not affect the basal levels of the enzymes studied. The potential use of alpha-tocopherol to prevent late complications of diabetes, including the onset of a porphyria like syndrome is considered.

5-Aminolevulinate Synthetase↗
PubMed1995

Alterations in fluorinated ether anesthetics effects on heme metabolism following chronic ethanol consumption.

1. The effect of enflurane or isoflurane anesthesia (1 ml/kg, i.p.) in animals chronically treated with ethanol (30%, v/v, in drinking water during a week) on heme metabolism and its regulation was investigated. 2. In those animals previously intoxicated with ethanol that received isoflurane, ALA-S activity was increased (control values: 0.071 +/- 0.022 nmol/mg, n = 10; treated animals: 0.110 +/- 0.034 nmol/mg, n = 8) and blood PBGase and deaminase were strikingly diminished (control values, n = 10: PBGase: 0.101 +/- 0.015 nmol/mg, deaminase: 0.242 +/- 0.075 nmol/mg; treated animals, n = 6: PBGase: 0.063 +/- 0.013 nmol/mg; deaminase: 0.145 +/- 0.045 nmol/mg). 3. The time-response study showed that liver ALA-S is enhanced at shorter times of anesthesia with isoflurane and that blood PBGase and deaminase appeared inhibited later in animals previously treated with ethanol. 4. Results reproduce some biochemical alterations known to occur in acute intermittent porphyria.

Animals↗
PubMed1995

High delta-aminolevulinic acid uptake in rat cerebral cortex: effect on porphyrin biosynthesis.

The response of nerve cells to high exogenous aminolevulinic acid (ALA) concentrations was studied by examining the changes in its uptake and in porphyrin biosynthesis. ALA was shown to be taken up by cerebral cortex particles by a non-saturable process. As opposed to other previously described experimental systems, it was also observed that 84-87% of porphyrins formed was found within the cells. Exposure of cerebral cortex particles to high exogenous ALA (0.8-4.0 mM) showed that ALA can be accumulated in relatively high concentrations in brain cells (21.04 +/- 1.05 nmol/mg protein). Under these experimental conditions, porphyrin biosynthesis was found to be markedly inhibited (52%). 2.4 mM ALA caused an initial stimulation of glucose uptake after 1 hr incubation and a later fall to below control values, being consistent with the fact that acute porphyric crisis could be precipitated by the action of ALA on energy metabolism. ALA toxicity could be due both to its accumulation in the cells and to deficient heme concentrations, with an additional effect on glucose metabolism. These findings provide the basis for a useful brain tissue model to investigate the nature of the metabolic mechanisms occurring in acute intermittent porphyria (AIP) patients.

Aminolevulinic Acid↗
PubMed1995

Mitochondrial and cytosolic rhodanese from liver of DAB treated mice. II. Some properties and spectral studies.

Rhodanese (thiosulfate: cyanide sulfurtransferase) shows distinctive mitochondrial and cytoplasmic activities in several models of tumorigenesis. To investigate the basis for these differences, the enzyme was purified from the mitochondrial and cytosolic liver fractions of mice treated with the carcinogen p-dimethyl-aminoazobenzene (DAB) and some properties were studied. Mitochondrial and cytoplasmic rhodanese exhibited different responses to the effect of ionic strength, denaturants, sulphydryl reagents, lipids and detergents, but no significant difference between enzymes purified from controls or DAB treated animals was observed. It is important to note that although chemical studies did not show very striking differences between either of the rhodanese forms, fluorescence spectral studies suggested that in DAB-treated mice, the cytosolic rhodanese would be present almost completely as the sulfur-free form, while the mitochondrial enzyme would be present as the sulfur-substituted form. These findings would justify the high rhodanese activity present in mitochondria. On the other hand, in control animals, rhodanese would exist only as the partial sulfur-substituted form in both fractions.

Adipates↗
PubMed1994

delta-Aminolevulinic acid dehydratase inactivation by uroporphyrin I in light and darkness.

1. The action of uroporphyrin I on erythrocytic ALA-D activity under dark and light conditions was examined. 2. Photo and non-photoinactivation of ALA-D induced by uroporphyrin I were observed. 3. Both effects were dependent on uroporphyrin concentration, temperature and time of exposure of the protein to the porphyrin. 4. Light-dependent effect of uroporphyrin I is related with the phototoxicity of porphyrins and could be produced by primary amino acid photooxidation followed by secondary cross-linking of the protein. 5. Light-dependent effect of uroporphyrin I could be ascribed to a direct enzyme inhibition due to binding of the porphyrin to the protein inducing structural changes at or near its active site.

Darkness↗
PubMed1994

How the atmosphere and the presence of substrate affect the photo and non-photoinactivation of heme enzymes by uroporphyrin I.

1. The effect of URO I on the activity of ALA-D, PBGase, deaminase and URO-D, both in aerobiosis and anaerobiosis, was studied. 2. Photoinactivation of the enzymes was much lower in an anaerobic than in an aerobic atmosphere. 3. Dark inactivation in the absence of oxygen was lower than its presence. 4. Preincubation in the presence of ALA or PBG protected the enzymic activity of ALA-D, PBGase and deaminase against URO I-inactivation both under u.v. light and in the dark. 5. Photoinactivating action of URO I would be mediated by reactive oxygen species generated by the excited porphyrin after its absorption of light. Dark inactivation, in aerobiosis, can also be partly mediated by amino acid oxidation, although to a lesser extent than that observed under u.v. light.

Aerobiosis↗
PubMed1994

Inhibition of porphobilinogenase by porphyrins in Saccharomyces cerevisiae.

The biosynthesis of uroporphyrinogen III, the precursor of hemes, chlorophylls, corrins and related structures, is catalyzed by the porphobilinogenase system (PBGase), a complex of two enzymes, PBG-Deaminase (PBG-D) and Isomerase. Although the separate enzymes have been studied in some detail less work has been performed on the properties of the complex. In this study the kinetic behaviour of the enzyme PBGase in a normal yeast strain, D273-10B, and its derivative B231 has been investigated. Uroporphyrinogen formation was linear with time up to 2 hr at 37 degrees C. The enzyme complex shows classical Michaelis-Menten kinetics. From the double reciprocal plots kinetic parameters were estimated for PBGase and PBG-D. Porphyrins were found to be competitive inhibitors with respect to porphobilinogen (PBG) and these compounds appeared to act as inhibitors by forming dead-end complexes with the free enzyme. 5-Aminolevulinic acid (ALA) also inhibited PBGase and this inhibition was overcome by addition of levulinic acid (2 microM). These results indicate that ALA, is not an inhibitor but acts through its conversion into porphyrins which are the true inhibitors.

Aminolevulinic Acid↗
PubMed1994

Effect of multiple doses of volatile anesthetics on heme enzymes.

1. The effect of the administration of several doses of Enflurane and Isoflurane (2 ml/kg, i.p., daily) on heme metabolism and glucose levels was studied. 2. Liver and kidney delta-Aminolevulinic acid synthetase (ALA-S) activities were 85% (P < 0.01) induced after the third dose of Enflurane, instead induction of this enzyme was only detected, in animals receiving one dose of Isoflurane. 3. Blood Porphobilinogenase and deaminase (50%, P < 0.01) inhibition was produced only when animals received a single dose of the anesthetics. 5. ALA-S induction observed after the third dose of anesthetics could be a consequence of long lasting depletion in heme synthesis produced by blocking at uroporphyrinogen level.

5-Aminolevulinate Synthetase↗
PubMed1994

Porphyrinogenesis in rat cerebellum. Effect of high delta-aminolevulinic acid concentration.

1. delta-Aminolevulinic acid (ALA) uptake as well as precursor accumulation and porphyrin biosynthesis were investigated in rat cerebellum, using as experimental approach minimal tissue units called particles. 2. ALA was shown to be taken up into cerebellum particles by a non saturable process up to 4.0 mM ALA whereas PBG and porphyrin formation exhibited a hyperbolic response reaching the plateau at about 1.0 and 1.5 mM ALA respectively. 3. Exposure of cerebellum particles to high exogenous ALA amounts (0.01-4.0 mM) indicated that ALA can be accumulated in relatively high concentrations in the cells (40 nmol/mg protein). Under these experimental conditions, PBG-D presented a low activity (3.25 pmol/mg protein/4 hr) showing to be a secondary control step in heme biosynthesis. 4. Incubation of cerebellum particles in the presence of a physiological concentration of glucose revealed that 1.0 mM ALA decreased glucose uptake by the cells (87% during 1 hr incubation), being consistent with the fact that acute attacks are precipitated by fasting and that sugar administration appeared to be an efficient treatment of AIP crisis. 5. These findings provide the basis for a useful model to study the nature of the metabolic mechanism underlying the acute attack.

Aminolevulinic Acid↗
PubMed1993

The role of ALA-S and ALA-D in regulating porphyrin biosynthesis in a normal and a HEM R+ mutant strain of Saccharomyces cerevisiae.

Catabolite repression and derepression on delta-aminolevulinate synthase (ALA-S) and delta-aminolevulinate dehydratase (ALA-D) in a normal yeast strain, D27, and its derived D27/C6 (HEM R+) were investigated. ALA-S and ALA-D activities and intracellular ALA (I-ALA) at different physiological states of the cells were measured. In YPD medium, under conditions of repression and when glucose was exhausted, both strains behaved identically as if the mutation was not expressed. In YPEt medium, however, both ALA-S and ALA-D activities were higher than in YPD, but the I-ALA content and the enzymic activity profiles shown by the two strains were quite different. It appears, therefore, that the mutation causes a deregulation of ALA-S, so that its activity is kept at a high level throughout the cell cycle. This would explain the increased levels of cytochromes present in the mutant. This mutation may affect some regulatory aspect of ALA formation and renders an ALA-S of high activity; moreover, this enzyme species seems to be more stable than in the normal strain.

5-Aminolevulinate Synthetase↗
PubMed1993

Delta-aminolevulinic acid transport in Saccharomyces cerevisiae.

1. This work represents the first approach to characterize the transport system of haem pathway precursors, such as delta-aminolevulinic acid (ALA), in two strains of Saccharomyces cerevisiae, a wild type, D27, and a HEM R+ mutant. 2. ALA transport occurs unidirectionally by a sole active system with an apparent KM of 0.10 mM, at the optimum pH of 5.0. ALA uptake is influenced by both the carbon and nitrogen source; this suggests a rather complex regulation mechanism. 3. This transport is not mediated by the general amino acid permease (GAP). 4. ALA uptake is strongly inhibited by compounds harboring a methyl-amine terminus suggesting that this group is essential for ALA transport; however, the electric environment of the carboxylic group may be also important for the interaction between ALA and its transporter active site. 5. We have found differences in ALA transport which would indicate a different regulation mechanism for this system in both strain cells.

Aminolevulinic Acid↗
PubMed1993

Photodynamic action of endogenously synthesized porphyrins from aminolevulinic acid, using a new model for assaying the effectiveness of tumoral cell killing.

1. The effectiveness of the photodynamic action of porphyrins, was studied by means of the tissue explant culture technique. A murine tumor tissue explant was incubated in a medium containing 0.6 mM of ALA for periods of 1 and 2 hr; total porphyrins synthesized under these conditions were of the same level as those found in our previous in vivo experiments. The explants were then irradiated for 30 min with He-Ne laser of 3.5 mW output power placed at a distance of 10 cm. Controls of non-irradiated tumor tissue slices incubated with and without ALA were performed. Immediately after irradiation, inocula of exactly 1 mm3 of the irradiated and non-irradiated tissue were subcutaneously injected under the right and left flanks of the same animal, respectively. The growth of the tumor was measured 15, 20 and 25 days after implantation. 2. Results obtained showed that the explants that were incubated for 1 hr with ALA and irradiated, reaching a concentration of 2.8 micrograms porphyrins/g tissue, produced a reduction of 50-70% of tumor size as compared with the non-irradiated controls incubated with ALA. Explants incubated for 2 hr, reaching a concentration of 4.6 micrograms porphyrins/g tissue, produced from 60% to complete lack of tumor growth. The effectiveness index (EI) of photoirradiation was calculated on the basis of the tumor growth in irradiated and non-irradiated tumors. EI was nearly 100% showing almost complete tumor cell destruction for tumor irradiated for 2 hr with 0.6 mM ALA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1993

Kinetics of porphyrin accumulation in cultured epithelial cells exposed to ALA.

1. The kinetics of porphyrin accumulation in cultured mammalian epithelial cells (CNCM-I-221) during exposure to ALA was investigated. 2. The total porphyrin synthesized is a function of ALA concentration and the incubation time. The cellular porphyrin content exhibited a saturation pattern, reaching a plateau at about 0.04 fmol porphyrins/cell. A biphasic time-dependent increase in the total porphyrin synthesized was observed. 3. After 3 hr of exposure to ALA the rate of synthesis increased to almost twice the initial rate, reaching between 0.02 and 0.05 fmol porphyrins/cell/hr depending on serum concentration in the medium. 4. Two effects of FBS on ALA-stimulated porphyrin accumulation were observed. Greater total porphyrin synthesis was found when incubations were made in 10% FBS compared to those in 1% FBS. 5. The higher serum concentration also caused a greater release into the medium of the porphyrins generated in the cells with a calculated half-life of 24 min in 10% serum-supplemented medium compared with 62 min in 1% serum. 6. The results obtained from cell synchronization experiments suggest that there is little obvious cell cycle-dependent variation in the synthesis of porphyrins from ALA. 7. The small differences in the intracellular porphyrin content that were observed may be attributed to a slight reduction in the rate of loss of porphyrins in G2/M cells.

Aminolevulinic Acid↗
PubMed1993

Porphyrins, porphyrias, cancer and photodynamic therapy--a model for carcinogenesis.

Porphyrins are the only and most powerful photosensitizers synthesized internally. To understand better the involvement of porphyrins in photosensitization reactions, the heme biosynthetic pathway is first described, as well as the main features of its regulation in both erythroid and hepatic cells. Most disorders of porphyrin metabolism, known as porphyrias, are characterized by porphyrin accumulation. A full discussion of these diseases, their classification and relevant biochemical and clinical signs are presented. Abnormalities in heme biosynthesis in disorders other than porphyrias, such as iron-deficient and sideroblastic anemias, lead poisoning, hereditary tyrosinemia, chronic renal disease and alcoholism, are briefly considered. A complete survey of the experimental research on the biosynthesis of porphyrins in tumors and of the important association between cancer and porphyrias is dealt with. The link to photodynamic therapy (PDT) emerges naturally and this is treated from the point of view of using porphyrins endogenously formed by the tumors for their localization and PDT. Finally, considering the nature of the alterations occurring in heme metabolism in tumors, and porphyrias and their ubiquity, a model is discussed where the abnormality of heme synthesis is involved in the initiating lesion of carcinogenesis. The model strongly predicts that the incidence of cancer will be high in cells with abnormal heme metabolism, suggesting that porphyric patients may be at greater risk of the development of cancer.

Aminolevulinic Acid↗
PubMed1992

Tumour-localizing properties of porphyrins. In vivo studies using free and liposome encapsulated aminolevulinic acid.

1. Using different doses of free and liposome encapsulated aminolevulinic acid (ALA) (between 2 and 8 mg/animal), given i.p., s.c. and intra-tumoural (i.t.), in vivo porphyrin synthesis by tumour, red blood cells (RBC) and different organs from tumour-bearing mice (TBM) and normal mice (NM) at different times, up to 24 hr after ALA administration, was examined. 2. It was found that by giving entrapped ALA, at a dose of 6 mg/animal (or 200 mg/kg wt), after 10 hr, a high level of porphyrin accumulation in the tumour was produced (7 micrograms/g tissue). Low synthesis occurred in muscle, lung, brain, RBC and skin; in spleen, kidney and liver synthesis is significant after 10 hr, but after 24 hr returned to normal values in the spleen and to about 2-3 micrograms/g tissue in the kidney and liver. 3. The tumour/skin porphyrin concentration ratio after 10 hr was nearly 30, the highest so far reported. 4. These results support our previous in vitro findings, indicating that free or encapsulated ALA might be used for early diagnosis of cancer and in photodynamic therapy.

Aminolevulinic Acid↗
PubMed1992

Rhodanese and ALA-S in mammary tumor and liver from normal and tumor-bearing mice.

1. Basal levels and allyl-isopropylacetamide (AIA) or veronal induced levels of delta-amino-levulinate synthetase (ALA-S), cytoplasmic and mitochondrial rhodanese were determined in tumor (T) and liver of both normal mice (NM) and T-bearing mice (TBM). 2. Rhodanese tumoral mitochondrial levels were higher than the hepatic normal mitochondrial fraction, while the cytoplasmic activity was nearly equal in all sources. 3. In neither case was the activity of tumoral ALA-S and rhodanese altered by any of the porphyrinogenic drugs. 4. Mitochondrial and cytoplasmic rhodanese activity was also measured in tumor and liver of TBM at different intervals after transplantation. We concluded that the behaviour of rhodanese is a property inherent to the tissue and not one attained with time.

5-Aminolevulinate Synthetase↗