Neuronal storage of histamine in the brain and tele-methylimidazoleacetic acid excretion in portocaval shunted rats.

Rats with portocaval anastomosis (PCA), an animal model of hepatic encephalopathy (HE), have very high brain histamine concentrations. Our previous studies based on a biochemical approach indicated histamine accumulation in the neuronal compartment. In this study, immunohistochemical evidence is presented which further supports the amine localization in histaminergic neurons.

Liver regeneration attenuates increased voluntary alcohol intake evoked by the liver damage.

Liver dysfunction induced in Wistar rats either surgically (by construction of portocaval anastomosis) or chemically (by chronic administration of thioacetamide) led to increased voluntary alcohol intake. Alcohol preference could be attenuated by liver regeneration that was triggered by a two-thirds hepatectomy done on cirrhotic rats. The brain serotonin system was activated in portocaval anastomosis rats and unchanged in thioacetamide-treated rats, thus suggesting that serotonin is not likely to be implicated in the mechanism(s) underlying development of alcohol preference in these rats.

Effect of pargyline on brain N-tele-methylhistamine in portocaval-shunted rats: relation to amine neurotransmitters.

HPLC determination of histamine, serotonin, dopamine, and noradrenaline in the brain tissue of rats with portocaval anastomoses (PCA) has revealed a selective increase in histamine concentration. In the posterior hypothalamus, the steady-state level of the amine metabolites showed an inverse pattern; N-tele-methylhistamine (t-MeHA), as estimated by gas chromatography-mass spectrometry, was not changed significantly by portocaval shunting, whereas 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid were more than doubled. Interestingly, the net increase in t-MeHA concentration in response to pargyline (80 mg/kg i.

The FAD dependent amine oxidases in relation to developmental state of enterocyte.

Epithelial cells from bovine and guinea pig small intestines contain monoamine and polyamine oxidases with MAO-A preponderance at any maturational stage. For either species, Km values for 5HT and N1acetylspermine remain throughout cellular maturation on the same levels, whereas the Vmax values do not. For serotonin, the dividing crypt cells showed in cow lower and in guinea pig higher Vmax than the mature cells; for N1acetylspermine, mature cells, independently of species, showed lower Vmax.

Histamine: its metabolism and localization in mammary gland.

1. Mammary gland of mouse (Mus musculus), rat (Rattus rattus), guinea pig (Cavia porcellus), cow (Bos taurus) and pig (Sus scrofa) contains different but always high concentrations of histamine. 2.

Influence of Tołpa Peat Preparation on the IgE-induced anaphylactic reactions in mice.

The ability of Tołpa Peat Preparation (TPP) to affect anaphylactic sensitization and mast cell secretory function was tested in BALB/c mice treated with TPP orally for 12 days. TPP in the doses of 20 and 50 mg/kg/day reduced histamine release from mouse peritoneal mast cells challenged with anti-IgE or concanavalin A in vitro. The treatment of mice with TPP from day 1 to day 12 of immunization with Ovalbumin (OA) absorbed on aluminium hydroxide gel resulted in a decrease of antigen-induced histamine release from mast cells of these mice in vitro and in decreased IgE antibody level in their sera.

Investigations on allergogenic properties of Tołpa Peat Preparation.

The ability of Tołpa Peat Preparation (TPP) to induce or enhance an allergic sensitization was tested on mice and guinea pigs. The levels of IgE antibody in the mouse sera and IgG1 as well as IgE antibody levels in guinea pig sera were evaluated by PCA (Passive Cutaneous Anaphylaxis) tests. TPP adsorbed on aluminium hydroxide gel (alum) and introduced into BALB/c mice by several subcutaneous injections was unable to stimulate the noticeable anti-TPP IgE antibody response.

The influence of Tołpa Peat Preparation (TPP) on rat liver regeneration.

The effect of Tolpa peat preparation (TPP) on the regenerative response has been examined in rats submitted to two thirds hepatectomy. The ornithine decarboxylase activity, spermidine and histamine levels, DNA and RNA content, RNA/DNA ratio and the mass of restituted liver were used to test the intensity of the regenerative processes. The action of TPP is dual: a short-term application of TPP at a dose of 20 mg/kg/day causes an inhibition of the ornithine decarboxylase activity, the decrease in spermidine formation, the levels of DNA and RNA, and liver restitution.

Decreased histamine content and metabolism in mammary cancer tissue from C3H mice.

Histamine (HA) level and its metabolism in adenocarcinoma mammae, spontaneously growing cancer in C3H mice, were examined in relation to the type of tumor, intensity of tumor vascularization and the presence or absence of a secretory function. Histamine concentration being in mammary gland one of the highest among mammalian organs (418 nmol/g) was decreased by 90% in tumor (34 nmol/g). Similarly, histidine decarboxylase (HDC) activity dropped from approximately 7.

The immunomodulating preparation Ukrain does not induce anaphylactic sensitization in mice and guinea pigs.

The ability of Chelidonium majus L. alkaloids derivative Ukrain to induce an anaphylactic sensitization was tested on mice and guinea pigs. The levels of IgE antibody in the mouse sera, and IgG1a, IgG1b as well as IgE antibody levels in guinea pig sera, were evaluated by passive cutaneous anaphylaxis (PCA) tests.

Histamine in C3H/W mice carrying spontaneous tumors of the mammary gland.

Adenocarcinoma mammae, a spontaneously growing mammary cancer in C3H/W mice, contrary to many transplanted tumors does not evoke any rise in histamine level either in the tumor or in distant tissues. On the other hand, the histamine level is reduced by 90% in the tumor in comparison with the healthy gland. This seems to be a consequence of the fall of histidine decarboxylase activity to below a detectable level.

Liver damage, voluntary alcohol intake and brain histamine.

Liver dysfunction induced by protocaval anastomosis (PCA) in the rat is associated with a great reduction of hepatic alcohol and aldehyde dehydrogenase activities. Despite this, PCA rats voluntarily drank more alcohol than unoperated rats. When subjected to forced alcohol consumption, shunted rats maintained their exaggerated voluntary alcohol intake whereas unoperated rats developed aversion to alcohol.

Brain histamine in rats with hepatic encephalopathy.

Chronic liver failure induced by portocaval anastomosis (PCA) in Wistar rats resulted in a dramatic increase in histamine concentration in hypothalamus and a smaller, but clearly pronounced, elevation in the rest of brain. Between 10 and 120 days following surgery, shunted rats exhibited a histamine level 2.4- to 13-fold higher in hypothalamus and 1.

Histamine metabolism in diabetic rats.

Streptozotocin-induced diabetes in rats has been used to study the effect of insulin deficiency on histamine metabolism. There were significant increases in the amine content in the pancreas and intestine, and a significant drop in intestinal diamine oxidase (DAO) activity. The reduced DAO activity may be of clinical relevance.

Neurotransmitters in hepatic encephalopathy.

The pathogenesis of hepatic encephalopathy (HE), a neuropsychiatric disorder resulting from liver failure, is still a matter of debate. Recently attention has been focused on brain neurotransmitters. The accumulating evidence indicates that the imbalanced metabolism and turnover as well as the altered functions of neurotransmitters (dopamine, noradrenaline, serotonin, GABA) and false neurotransmitters (phenylethanolamine, octopamine, synephrine) may be of high importance in the pathomechanism of HE.

Histamine catabolism in proliferating skin.

The histamine (HI) content and the activities of the enzymes involved in its degradation have been studied in guinea pig skin after stimulation of epidermal proliferation. As compared with unstimulated skin the HI content and histamine N-methyltransferase (HMT) activity in the stripped skin were reduced at the time of increased epidermal proliferation and were higher than the normal when the epidermis becomes hyperplastic. Diamine oxidase (DAO) followed an inverse pattern.

Participation of aldehyde dehydrogenase in the oxidative deamination pathway of histamine and putrescine.

Some guinea pig tissue homogenates have shown the ability to catabolize, in vitro, imidazoloacetaldehyde (ImAAL) and gamma-aminobutyraldehyde (GABAL) via NAD-dependent aldehyde dehydrogenase (ALDH, EC 1.2.1.