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PubMed1986

Changes in Amines and Biosynthetic Enzyme Activities in p-Fluorophenylalanine Resistant and Wild Type Tobacco Cell Cultures.

The levels of free amines and the activities of their biosynthetic enzymes were measured in a p-fluorophenylalanine resistant Nicotiana tabacum L. cv Xanthi cell line (TX4) which accumulates high levels of cinnamoylamides, and a wild type cell line (TX1). Putrescine in TX1 and spermidine in TX1 and TX4 increased 4-fold by day 4 but declined by day 8 of the culture period. Spermine levels were consistently low, while tyramine was not found in TX1 until day 9 when a gradual rise was noted. Ornithine decarboxylase activity in TX1 and TX4 increased slightly through day 2 but declined gradually thereafter. S-Adenosylmethionine decarboxylase activity remained low throughout the culture period, and tyrosine and arginine decarboxylases in TX1 were very low in activity. In contrast, the activities of tyrosine and arginine decarboxylases were elevated in TX4, but a 3-fold increase in tyramine after a subculture was not accompanied by a rise in tyrosine decarboxylase. However, tyrosine decarboxylase activity did increase during a second rise in tyramine levels in aging cells, late in the culture period. Although significant differences exist in amine levels, between TX4 and TX1, it is unclear how altered amine metabolism relates to p-fluorophenylalanine resistance.

Journal Article↗
PubMed2005

Multiplex PCR method for the simultaneous detection of histamine-, tyramine-, and putrescine-producing lactic acid bacteria in foods.

In a screening of primers, we have selected three pairs of primers for a multiplex PCR assay for the simultaneous detection of lactic acid bacteria (LAB) strains, which potentially produce histamine, tyramine, and putrescine on fermented foods. These primers were based on sequences from histidine, tyrosine, and ornithine decarboxylases from LAB. Under the optimized conditions, the assay yielded a 367-bp DNA fragment from histidine decarboxylases, a 924-bp fragment from tyrosine decarboxylases, and a 1,446-bp fragment from ornithine decarboxylases. When the DNAs of several target organisms were included in the same reaction, two or three corresponding amplicons of different sizes were observed. This assay was useful for the detection of amine-producing bacteria in control collection strains and in a LAB collection. No amplification was observed with DNA from nonproducing LAB strains. This article is the first describing a multiplex PCR approach for the simultaneous detection of potentially amine-producing LAB in foods. It can be easily incorporated into the routine screening for the accurate selection of starter LAB and in food control laboratories.

Amino Acid Sequence↗
PubMed1987

Tumor-promoting phorbol ester amplifies the inductions of tyrosine aminotransferase and ornithine decarboxylase by glucocorticoid.

In adrenalectomized rats, the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) markedly enhanced the inductions of tyrosine aminotransferase (TAT) and ornithine decarboxylase by glucocorticoids, even with sufficient concentration of glucocorticoids to have a maximal effect, whereas it had no effect on TAT activity and increased ornithine decarboxylase activity only slightly in the absence of glucocorticoids. Phorbol derivatives and components of TPA such as 4 beta-phorbol, phorbol 12-tetradecanoate, phorbol 13-acetate, and 4-O-methylphorbol 12-tetradecanoate 13-acetate, which have no tumor-promoting activity or ability to activate protein kinase C, did not have any effect on TAT induction by glucocorticoid. TPA enhanced the induction of TAT by various glucocorticoids but had no effect on induction of TAT by glucagon or insulin and did not enhance the induction of glucose-6-phosphate dehydrogenase by 17 beta-estradiol. These results suggest that TPA specifically enhances the induction of TAT and ornithine decarboxylase by glucocorticoids. Similar effects of TPA on TAT induction by glucocorticoid were observed in primary cultures of adult rat hepatocytes. Another activator of protein kinase C, rac-1,2-dioctanoylglycerol, was also found to have similar effects on the cells.

Adrenalectomy↗
PubMed1984

Induction of ornithine decarboxylase and augmentation of tyrosine aminotransferase activity by N-hydroxy-2-acetylaminofluorene and 2-acetylaminofluorene in rat liver. Influence of sex, retinylacetate, indomethacin, and pentachlorophenol.

IP injection in rats of 2-acetylaminofluorene (AAF) or N-hydroxy-2-acetylaminofluorene (N-OH-AAF) resulted in a transient increase of hepatic ornithine decarboxylase (ODC) and tyrosine aminotransferase (TAT) activity. Maximal activity of ODC was observed 4 hr and of TAT 3 hr after administration of either AAF or N-OH-AAF. A lag-time of 2 hr preceded the increase of ODC and TAT activity. N-OH-AAF dependent ODC induction displayed an almost linear dose-response in the dose range up to 94.1 mumol/kg bw (body weight) when the ODC activity was measured at its maximum 4 hr after administration. Elevation of the dose N-OH-AAF to 126 mol/kg bw resulted in a lower ODC induction. Administration of doses AAF to 31.4 mumol did not change ODC activity. At doses up to 126 mumol/kg bw ODC induction increased linear. TAT induction increased linear in the dose range 15.7-94.1 mumol N-OH-AAF and 31.4-94.1 mumol AAF/kg. Lowering the dose of AAF did not result in a lower ODC or TAT activity. Judged by the effects of actinomycin D or cycloheximide administered 1 hr prior to AAF or N-OH-AAF, the in vivo induction of rat liver ODC activity by AAF and N-OH-AAF appeared to be under transcriptional control, whereas augmentation of TAT activity under influence of AAF or N-OH-AAF appeared the result of (post) translational events. Induction of ODC by AAF or N-OH-AAF was not significantly changed by indomethacin, was slightly increased by pentachlorophenol (PCP) and was synergistically enhanced by retinylacetate (RA). The increase of TAT activity was stimulated by PCP and RA. The effect of PCP indicates that N-sulfonoxy-2-acetylaminofluorene is most probably not involved in the induction of ODC. AAF appeared more effective hepatic ODC inducer in females than males and moreover more effective than N-OH-AAF in females. N-OH-AAF had stronger ODC inducing capacity in males than females. Similar observations were made with respect to TAT activity. When induction of ODC is indicative for a tumor promoting property then the data presented here suggest that tumor promotion of the complete carcinogens AAF and N-OH-AAF is not mediated by N-O-sulfation; this might be due to other metabolic conversions.

2-Acetylaminofluorene↗
PubMed2000

Formation of biogenic amines in raw milk Hispánico cheese manufactured with proteinases and different levels of starter culture.

Two proteinases, a neutral proteinase from Bacillus subtilis and a cysteine proteinase from Micrococcus sp., were used to accelerate the ripening process of raw cow's milk Hispánico cheese, a semihard variety. Two levels (0.1% and 1%) of a commercial starter culture containing Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris were added for cheese manufacture. The influence of both factors, proteinase addition and level of starter culture, on the growth of amino acid-decarboxylating microorganisms and on the formation of biogenic amines during cheese ripening was investigated in duplicate experiments. The population of tyrosine decarboxylase-positive bacteria, which represented less than 1% of the total bacterial population in most cheese samples, and tyrosine decarboxylase-positive lactobacilli was not influenced by proteinase addition or level of starter culture. Tyramine was detected in all batches of cheese from day 30. Its concentration was significantly (P < 0.05) influenced by proteinase addition but not by the level of starter culture and increased with cheese age. After 90 days of ripening, 103 to 191 mg/kg of tyramine was found in the different cheese batches. Histamine was not detected until day 60 in cheese with neutral proteinase and 1% starter culture and until day 90 in the rest of the cheeses. The concentration of this amine did not exceed 20 mg/kg in any of the batches investigated. Phenylethylamine and tryptamine were not found in any of the samples.

Animals↗
PubMed1997

Tyrosine hydroxylase and DOPA decarboxylase activities in the medical preoptic area and arcuate nucleus during the estrous cycle: effects of aging.

HPLC and Palkovits' microdissection technique were used to measure activities of two catecholamine-synthesizing enzymes, tyrosine hydroxylase (TH) and dopa decarboxylase (DD), in the medial preoptic area (MPA) and arcuate nucleus (AN), both of which are involved in LH regulation. The measurements were made during an 8-h period at 1200, 1400, 1600, 1800, and 2000 h on the days of proestrus and diestrus in young (4-5-month-old) rats. Similar measurements were made at 1400, 1600, 1800, and 2000 h in middle-aged (8-10-month-old) proestrous rats and in 18-22-month-old persistently diestrous rats. For each hour (1200, 1400, etc.), five to seven rats were used. In the young proestrous rats, TH activity in the MPA increased progressively to maximum levels at 1800 h, which is approximately the time when the proestrous surge of LH is known to occur. In contrast, in the young diestrous rats, in which serum LH is known to remain stable, TH activity remained unchanged throughout the afternoon. As in the young proestrous rats, in the middle-aged proestrous rats TH activity reached a peak at 1800 h followed by a precipitous decline at 2000 h. As in the young diestrous rats, in the old persistently diestrous rats no changes in TH activity were observed. The profiles of TH activity in the AN of the four groups were essentially similar to those in the MPA. The cyclic changes in TH activity observed in this study provide a basis for the reported cyclic changes in NE activity, which, in turn, are believed to be responsible for cyclic changes in LH release. The marked deficiency and absence of changes in TH activity in the acyclic old animals corresponded to the reported marked decrease and absence of fluctuations in catecholamine activity in old age. A correlation between DD activities and catecholamine activities was not obvious, most probably due to the large number of compounds that are known to be substrates for this enzyme.

Aging↗
PubMed1963

Dopamine-beta-oxidase activity in man, using hydroxyamphetamine as substrate.

Hydroxyamphetamine was administered orally to five human subjects in daily doses of 26 to 118 mg. Approximately half the dosage administered was recoverable in the urine as unchanged drug (free plus conjugated) and 3.7 to 9.1% was excreted as the beta-hydroxylated metabolite, hydroxynorephedrine (free plus conjugated). Since conversion of hydroxyamphetamine to hydroxynorephedrine occurs in vitro by the action of dopamine-beta-oxidase, a simple method is suggested for measuring the activity of this enzyme and the effect of its inhibitors in man. No impairment of beta-hydroxylation was noted in an adrenalectomized subject. The beta-hydroxylation of hydroxyamphetamine in vivo has not been described previously.

Dopamine↗
PubMed1991

Co-localization of tyrosine hydroxylase and glutamate decarboxylase in a subpopulation of single nigrotectal projection neurons.

The neurotransmitter phenotype(s) of nigral neurons innervating the superior colliculus (SC) in the rat was examined using a combination of immunohistochemical techniques and fluorescent retrograde tracing. After double-immunofluorescent histochemistry for tyrosine hydroxylase (TH) and glutamate decarboxylase (GAD), single cells in the rostral ventrolateral portion of the substantia nigra pars reticulata (SNr) and to a lesser extent the substantia nigra pars lateralis (SN1) displayed immunoreactivity to both antigens. Furthermore, following True blue (TB) injections into the SC and incubation for both TH and GAD immunoreactivity, a considerable number of cells in the SNr retrogradely labeled with TB (approximately 10%) were also immunopositive for both synthetic enzymes. The present study provides evidence for the coexistence of TH and GAD and thus, the coexistence of dopamine and GABA in a subpopulation of single nigrotectal projection cells.

Animals↗
PubMed1986

Use of high concentrations of glutaraldehyde for immunocytochemistry of transmitter-synthesizing enzymes in the central nervous system.

Aldehyde fixatives containing high concentrations of glutaraldehyde, usually used for conventional electron microscope studies, were successfully used for immunocytochemistry of transmitter synthesizing enzymes, glutamate decarboxylase and tyrosine hydroxylase, in the rat central nervous system. Although a high concentration of glutaraldehyde could cause tremendous non-specific staining, this was almost completely absent after treating sections with 1% sodium borohydride for 30 min. Furthermore, it was shown that a high concentration of glutaraldehyde might cause no appreciable reduction of the antigenicities of glutamate decarboxylase and tyrosine hydroxylase when compared with fixatives containing a low concentration of glutaraldehyde. It is suggested that fixatives containing high concentrations of glutaraldehyde are very useful, not only for conventional electron microscope studies, but also for light and electron microscope immunocytochemistry of some antigens, including glutamate decarboxylase and tyrosine hydroxylase.

Aldehydes↗
PubMed1988

Catecholaminergic innervation of pyramidal and GABAergic nonpyramidal neurons in the rat hippocampus. Double label immunostaining with antibodies against tyrosine hydroxylase and glutamate decarboxylase.

This study describes the catecholaminergic innervation of rat hippocampal neurons at the electron microscopic level by using an antibody against tyrosine hydroxylase (TH) and immunocytochemical techniques. In a first series of experiments, the course and distribution as well as the synaptic contacts of TH-immunoreactive fibers were analyzed with the peroxidase-antiperoxidase (PAP) method. Next, peroxidase immunostaining of TH fibers was combined with glutamate decarboxylase (GAD) immunostaining, using avidinated ferritin as a second electrondense marker. Our results demonstrate that TH-immunostained terminals establish asymmetric synaptic contacts with spines of pyramidal neurons, and symmetric synaptic contacts with cell bodies and dendritic shafts of ferritin-labeled GAD-immunoreactive nonpyramidal cells.

Animals↗