Comparative analysis of monoamine producers in the major duodenal papilla and lungs of rabbits]

By means of incubation of slices in 2% solution of glyoxylic, acid adrenergic nervous structures and endocrine cells (APUD cells) have been studied in the ampule wall of the duodenal large papilla and in the lungs in 6 mature male rabbits. Topographic proximity of APUD cells and adrenergic nervous fibers is noted. Contents of serotonin and catecholamines in the structures mentioned have been investigated microfluorometrically. Simultaneous revealing of producers of monoamines make possible to suppose that serotonin and catecholamines get paracrinically from the APUD cells into terminals of the adrenergic nervous fibers.     

Fluorescence of neurotransmitters and their reception in plant cell

The use of fluorescent reagents for the histochemical detection of catecholamines or histamine, as well as luminescent antagonists of the intracellular neurotransmitters revealed that they can bind to certain cellular compartments. After the treatment with glyoxylic acid (a reagent used for the detection of catecholamines), blue fluorescence with maximum at 460–475 nm was visualized in nuclei and chloroplasts (in control preparations no emission in this spectral region was recorded), as well as an intense fluorescence, exceeding the control level, in the vacuoles. After the exposure to ortho-phthalic aldehyde (a reagent used for the histamine detection), blue emission was more noticeable in nuclei and chloroplasts, which correlates with previously observed effects on intact cells, such as pollen and vegetative microspores. A comparison of the intensities of the biogenic amine-related emission in various organelles showed that the greatest emission was in vacuoles and the weakest, in chloroplasts. Thus, on the surface, and possibly within the organelles, fluorescence could demonstrate the presence of biogenic amines. Antagonists of the neurotransmitters (dtubocurarine for acetylcholine; yohimbine for dopamine; norepinephrine and inmecarb for serotonin), which fluoresce in the blue and blue-green region and usually bind with the plasmalemma of intact cells, also interacted with the membranes of the organelles studied. Fluorescence intensity depended on the object; most prominent it was for yohimbine in the outer membrane of the nucleus, vacuoles, and chloroplasts.     

Effect of withdrawal from chronic ethanol ingestion on the cAMP response of cerebral cortical slices using the agonists histamine, serotonin, and other neurotransmitters.

The effect of ethanol withdrawal on the cAMP response of cerebral cortical brain slices was studied. The cAMP response was evoked in vitro by various neurotransmitters including norepinephrine (NE), histamine, serotonin, dopamine, acetylcholine, and gamma-aminobutyric acid (GABA). The cAMP response to NE and histamine was enhanced by ethanol withdrawal. Serotonin evoked a cAMP response in the brain slices from ethanol-withdrawal rats but not in pair-fed controls. The histamine and serotonin evoked responses were blocked by chlortripolon and methysergide, respectively. The responses to histamine and serotonin were also blocked by alpha- and beta-adrenergic antagonists, possibly because of the nonspecific membrane stablizing effect of these antagonists. GABA inhibited the NE stimulated cAMP response possibly through the hyperpolarizing action of GABA. The results support the hypothesis that ethanol withdrawal induces a nonspecific postjunctional supersensitivity. It is postulated that the supersensitivity involves a partial depolarization of the receptor membrane. Alternative hypotheses are reviewed.     

Localization of catecholamines, serotonin and histamine in the cells and mucus of bronchial washings from apparently healthy subjects

By means of luminescent-histochemical methods localization of catecholamines, serotonin, histamine has been studied in cells and mucus of bronchial washings of 30 practically healthy persons. Cytofluorometry is performed in mucus, pulmonary epithelium, alveolar macrophages, lymphocytes and neutrophils of the bronchial washings. In the alveolar macrophages a high level of the compounds studied is detected.     

Serotonin and histamine receptor-mediated inhibition of serotonin and noradrenaline release in rat brain cortex under nimodipine treatment

Rat brain cortex slices preincubated with [³H]serotonin or [³H]noradrenaline (25 100 nmol/l each) were superfused and the effects of serotonin and histamine on the electrically (0.3 or 3 Hz) evoked tritium overflow were studied.

In slices preincubated with [³H]serotonin the extent of inhibition of the electrically (3 Hz) evoked tritium overflow produced by histamine was increased when the concentration of [³H]serotonin used for incubation was decreased. The evoked overflow tended to be lower in slices from 2-year-old rats than in slices from 6-month-old animals whereas the inhibitory effect of histamine on the evoked overflow did not differ. Treatment of rats with nimodipine for at least 6 weeks did not significantly affect the evoked overflow in slices from 6-month and 2-year-old rats nor did it significantly alter the serotonin- and histamine-mediated inhibition of the evoked overflow in slices from young adult rats. The extent of histamine-mediated inhibition of the electrically evoked tritium overflow from slices (of young adult rats) preincubated with [³H]noradrenaline did not change when the concentration of [³H]noradrenaline used for incubation was decreased; the degree of inhibition markedly increased when the frequency of stimulation was lowered from 3 to 0.3 Hz. The inhibitory effect of histamine on the electrically (0.3 Hz) evoked overflow was mimicked by the H₃ receptor agonist R-(−)--methylhistamine and antagonized by the H₃ receptor antagonist thioperamide. The electrically evoked overflow and its inhibition by histamine were not affected by nimodipine, irrespective of whether the Ca²⁺ antagonist was administered in vivo (for at least 6 weeks) or added to the superfusion medium in vitro.

It is concluded that (1) the extent of the H₃ receptor-mediated effect in rat brain cortex slices can be markedly increased by lowering the concentration of the tracer in slices preincubated with [³H]serotonin and by lowering the stimulation frequency in slices preincubated with [³H]noradrenaline; (2) the H₃ receptor-mediated inhibition of serotonin release is not changed during aging and (3) nimodipine does not significantly influence serotonin release and noradrenaline release and their serotonin and/or histamine receptor-mediated modulation.     

Localization of catecholamines, serotonin, histamine and acetylcholinesterase in human peripheral blood structures

By means of various histochemical methods localization of biologically active compounds in structure of peripheral blood of 66 practically healthy persons have been studied. In the blood structures studied (plasma, erythrocytes, neutrophilic granulocytes, lymphocytes) catecholamines, serotonin, histamine and acetylcholinesterase are distributed unevenly. In leucocytes their content is the greatest.     

Regulatory role of monoamine neurotransmitters in Saccharomyces cerevisiae cells

Proliferation of Saccharomyces cerevisiae EPF cells on solid maltose-peptone-yeast extract (MPY) medium was stimulated by the addition of monoamine neurotransmitters. Dopamine turned out to be the most efficient among them: it caused approximately 8-fold growth stimulation at 1 microM concentration. The dopamine effect was partly mimicked by apomorphine, a dopamine receptor agonist. Serotonin and histamine produced less significant (1.5-2-fold) effects, and norepinephrine virtually failed to stimulate yeast culture growth. These data point to a specific, apparently receptor-dependent mode of action of the tested neurotransmitters on S. cerevisiae cells. Using high efficiency liquid chromatography, serotonin, catecholamines (dopamine and norepinephrine), catecholamines precursor dioxyphenylamine, and oxidized amine products (homovanilic acid, dihydrophenylacetic acid, and 5-hydroxyindolacetic acid) were established to be accumulated in yeast cells up to (sub)micromolar concentrations without their release into the culture fluid supernatant (CSF). The results obtained suggest that the tested amine neurotransmitters and related compounds do not serve as autoregulators in the yeast population. Nevertheless, they may be involved in the regulation of yeast population development by other ecosystem components.     

ADENOSINE 3'',5''-MONOPHOSPHATE IN GUINEA PIG CEREBRAL CORTICAL SLICES: EFFECTS OF α- AND β-ADRENERGIC AGENTS, HISTAMINE, SEROTONIN AND ADENOSINE

—Norepinephrine and epinephrine, in combination with either adenosine or histamine, enhanced the accumulation of cyclic AMP in guinea pig cerebral cortical slices. Isoproterenol had only marginal effects under the same conditions. Studies with d- and l-norepinephrine and with the α- and β-adrenergic blocking agents, phenoxybenzamine, phentolamine, dihydroergokryptamine, propranolol and sotalol, indicated that the effect of catecholamines on cyclic AMP levels in this tissue was stereo-specific and was mediated primarily via interaction with a classical α-adrenergic receptor. Studies with the antihistaminics, diphenhydramine and pheniramine, and the antiserotonin agent, methysergide, indicated that guinea pig cerebral cortical slices contain receptors for histamine and serotonin, whose activation also stimulates an enhanced accumulation of cyclic AMP in the presence of adenosine.     

Localization of biogenic monoamines in the dura mater of the rat brain

Quantitative and qualitative composition of catecholamines (noradrenaline and dophamine) and indolalkylamines (serotonin and tryptamine) and their localization have been studied in cells and neural fibers of the rat dura mater. Luminiscent-cytophotometric and electron microscopic methods have revealed two types of cells depositing biogenic monoamines. As demonstrate the experiments with rausedil injection, monoaminocytes of the first type (mast cells) contain predominantly indolalkylamines and a small amount of dophamine. Monoaminocytes of the second type (chromaffin cells) synthesize mainly serotonin and, perhaps, tryptamine. In adrenergic neural fibers only noradrenaline has been found to be present.     

Studies on the specificity of uptake and release of radiolabelled histamine in rat brain slices

Previously it has been shown that radiolabelled histamine is taken up by brain slices and may subsequently be released by depolarizing stimuli in a calcium-dependent manner, indicating the involvement of neurons in uptake and release of histamine.The present study demonstrates that after incubation of brain slices with low (nM) concentrations of [³H]histamine the amine may be taken up by (and released from) dopaminergic and serotonergic neurons (nerve terminals). Thus 6-hydroxydopamine- and 5,7-dihydroxytryptamine-induced lesions not only reduced the uptake of [³H]dopamine (in striatal slices) and [³H]serotonin (in hippocampal slices), but also, though to a lesser extent, that of [³H]histamine. Immunocytochemical findings revealed that the neurotoxins did not visibly affect histaminergic neurons. Lesioning of noradrenergic neurons appeared not to alter significantly the uptake of [³H]histamine. Further, various drugs acting on either catecholamine-, serotonin- or opioid-receptors and known to cause presynaptic inhibition of the release of [³H]dopamine or [³H]wrotonin from striatal or hippocampal slices also inhibited [³H]histamine release.It is concluded that incubation of brain slices with low concentrations of [³H]histamine does not result in a selective labelling of histaminergic neurons. The possibility that, unlike other monoamines, histamine is not subject to high-affinity uptake by the nerve terminals from which it was released, is discussed.     

Gender differences in the histamine and serotonin content of blood,peritoneal and thymic cells: a comparison with mast cells

The serotonin and histamine content of mast cells and white blood cells in adult male and female rats was compared, using a flow cytometric immunological method. Serotonin was significantly higher in female peritoneal mast cells, peritoneal monocyte-ganulocyte-macrophage cells, blood lymphocytes and blood thymocytes. Histamine was significantly higher in female peritoneal monocyte-granulocyte-macrophage cells, and blood lymphocytes, monocytes and granulocytes, but was significantly less in thymocytes. Peritoneal lymphocytes and the monocyte-granulocyte-macrophage group contained significantly more histamine than mast cells. These experiments call attention to gender differences in the levels of biogenic amines in cells participating in defence reactions, and to the possible non-unique role of mast cells in serotonin and histamine supply.     

The effect of locally injected vasoactive amines on the elicitation of delayed-type hypersensitivity.

In previous work monoamine depletion due to treatment with reserpine was shown to decrease the elicitabiltiy of DTH responses in mice. In addition, treatment with monoamine oxidase inhibitors prevented the reserpine-induced decrease. These findings led to the suggestion that serotonin-induced increased vascular permeability is necessary to the development of DTH reactions, perhaps by allowing bone marrow-derived macrophage precursor cells, which are obligate components of DTH responses, to migrate through specialized venules into the site of the reaction. We have compared classical drug tachyphlaxis (temporary inhibition of the effects of a drug by prior treatment with agonists) to serotonin in vessels of mouse feet with local inhibition of DTH after serotonin pretreatment of mice. During the tachyphylactic period, DTH responses are depressed. This suggests that serotonin-induced tachyphylaxis of local endothelial receptors can be responsible for DTH inhibition. In contrast, local injection of histamine has no effect on DTH and this drug is a much less potent inducer of tachyphylaxis to serotonin-mediated vasoactive reactions. On the other hand, histamine can inhibit in vitro T cell reactions, which are not affected by serotonin. These data help to further the concept that serotonin plays an important role in the regulation of DTH in mice and that it probably does so by acting on vascular endothelium.     

beta-D-N-acetylglucosaminidase, a new cytochemical marker of human lymphocyte subpopulations

beta-D-N-acetylglucosaminidase staining characteristics of rosetted or non-rosetted normal and malignant lymphoid cells were compared with those observed after nonspecific esterase and acid phosphatase staining. With the three cytochemical techniques a similar staining pattern was observed in T cells (E-rosettes), their subpopulations T mu and T gamma, B cells and the non-T, non-B cells, as well as in the T cell populations defined with the monoclonal antibodies OKT3,4 and 8. T mu cells mostly displayed a "dot-like" reaction, T gamma and the non-T, non-B cells a "fine to heavy granular" reaction, while most B cells were negative. OKT4 and OKT8 positive lymphocytes showed for the larger part a dot-like staining pattern, however, the frequency of cells with a granular pattern was distinctly higher in the OKT8, than in the OKT4 positive cells. E(+)mIg(-) and E(-)mIg(-) A.L.L. blasts stained either with a dot-like or granular pattern or failed to react when stained cytochemically for beta-D-N-acetylglucosaminidase, nonspecific esterase and acid phosphatase activity. Only in a few instances a discrepancy was observed between the types of staining for esterase and acid phosphatase on one hand and those for beta-D-N-acetylglucosaminidase on the other.     

Mechanism of the protective effect of adaptation to hypoxia on the development of allergic arthritis

It has been established that adaptation of Wistar rats to high-altitude hypoxia led to a reduction of inflammatory lesions occurring in adjuvant arthritis. It has been shown that the mechanisms associated with a decrease in the content of mediators (serotonin, histamine) of the chemical and pathophysiological stages of allergic reactions formation in the adapted animals underlie the protective effect of adaptation. Adaptation to hypoxia appreciably lowered the sensitivity of the sensitized rats to serotonin.     

Effects of biogenic amines on the formation of adenosine 3',5'-monophosphate in human thyroid slices.

The effects of various concentrations of biogenic amines on the formation of adenosine-3', 5'-monophosphate (cyclic AMP) and their interactions with other thyroid stimulators were investigated in human thyroid slices from normal and Graves' disease. Most of biogenic amines were found to have the stimulatory effects to some extent. Among the biogenic amines tested, histamine was the most potent thyroid stimulator, norepinephrine and serotonin, the intermediate in terms of cyclic AMP formation. The effect of histamine was almost as potent as TSH in thyroid slices from Graves' disease. This stimulatory effect of histamine was blocked by metiamide, a histamine H2-receptor antagonist, but not by chlorpheniramine, a histamine H1-receptor antagonist. The effect of norepinephrine was completely inhibited by propranolol, but not by phentolamine. Polyphloretin phosphate did not inhibit norepinephrine- or histamine-induced cyclic AMP formation, while it significantly depressed cyclic AMP formation induced by prostaglandin E2. The maximal effect of histamine was additive to that of TSH. It is suggested that biogenic amines, histamine and norepinephrine, in particular, have the thyroid receptors different from that of TSH or prostaglandin E2 and could play an important role in thyroid physiology.     

Effects of biogenic amines on the formation of adenosine 3', 5'-monophosphate in human thyroid slices.

The effects of various concentrations of biogenic amines on the formation of adenosine-3', 5'-monophosphate (cyclic AMP) and their interactions with other thyroid stimulators were investigated in human thyroid slices from normal and Graves' disease. Most of biogenic amines were found to have the stimulatory effects to some extent. Among the biogenic amines tested, histamine was the most potent thyroid stimulator, norepinephrine and serotonin, the intermediate in terms of cyclic AMP formation. The effect of histamine was almost as potent as TSH in thyroid slices from Graves' disease. This stimulatory effect of histamine was blocked by metiamide, a histamine H2-receptor antagonist, but not by chlorpheniramine, a histamine H1-receptor antagonist. The effect of norepinephrine was completely inhibitied by propranolol, but not by phentolamine. Polyphloretin phosphate did not inhibit norepinephrine- or histamine-induced cyclic AMP formation, while it significantly depressed cyclic AMP formation induced by prostaglandin E2. The maximal effect of histamine was additive to that of TSH. It is suggested that biogenic amines, histamine and norepinephrine, in particular, have the thyroid receptors different from that of TSH or prostaglandin E2 and could play an important role in thyroid physiology.     

Structure and histochemistry of the normal intestine of the fowl. I. The mature absorptive cell

Synopsis The fine structure and cytochemistry of the intestinal epithelial cell of the fowl have been investigated. The fine structure of the mature absorptive cell of the fowl duodenum was very similar to that described for man and other mammals. Minor differences were the thinner microvillous glycocalyx, the unusual length of the cells and their microvilli, and the wide distribution of lysosomal bodies. The membrane-associated enzymes alkaline phosphatase, ATPase (pH 7.2) and leucine naphthylamidase were mainly associated with the brush border; this organelle also gave positive reactions for mucopolysaccharides and phospholipids. No enzyme activities were found in the terminal web.The distribution of lysosomes between the terminal web and the Golgi apparatus was correlated with the granular localization of the lysosomal enzymes acid phosphatase, -glucuronidase and non-specific esterase. The mitochondrial enzyme succinate dehydrogenase was seen to be localized in rod-like dots which marked the distribution of mitochondria in the absorptive cell. The localization of mitochondrial ATPase (pH 9.4) was not clearly demonstrated because of diffusion artifacts. The region of the Golgi apparatus gave a strong reaction for thiamine pyrophosphatase, together with weak reactions for acid and alkaline phosphatases after extensive overincubation.The endoplasmic reticulum-associated enzymes glucose-6-phosphatase and nonspecific esterase were distributed throughout the absorptive cell, with a maximum activity apical to the Golgi apparatus. Additionally, the jejunal absorptive cells showed endoplasmic reticulum-as well as lysosomal-associated -glucuronidase.     

Histological and histochemical studies on the distribution of a few enzymes in the neoplastic liver of Uroloncha malabarica (Linnaeus)

The present work describes histological and histochemical observations made on the neoplastic liver of Indian silver bills, Uroloncha malabarica. The histology of neoplastic tissue as well as liver has been discussed. Further, a few enzymes like alkaline phosphatase, acid phosphatase, 5-nucleotides and non-specific esterase have been localized in the diseased liver. The occurrence of lymphocytoma caused a marked change in the localization of the enzymes. Sometimes total inhibition of the enzyme was encountered. Damaged sinusoid cells and bile canaliculi of the neoplasm as well as liver lobules show no reaction for alkaline phosphatase. However, its counterpart, acid phosphatase, exhibits intense activity in both neoplastic tissue and liver cells. Aggregates of neoplastic tissue give moderate 5-nucleotidase reaction while it gives poor activity in hepatic tissue of the diseased liver. Parenchymatous cells are able to give some activity for the non-specific esterase while it is very dull in the neoplastic tissue.     

Vesicular monoamine transporters in the rat stomach.

Cellular distribution of vesicular monoamine transporters (VMATs), known to regulate vesicular storage and release of biogenic amines (i.e., catecholamines, serotonin, histamine, etc.), have been studied in the rat stomach using in situ hybridization histochemistry (ISHH) and immunohistochemical (IHC) techniques. 35S-UTP labeled riboprobes showed that mRNAs of both VMATs are expressed in the gastric mucosa. A combination of ISHH and IHC verified that most of the parietal cells (among other epithelial cells) express mRNA of the peripheral type transporter (VMAT1) while enterochromaffin-like cells (ECL) of the fundic mucosa express mRNA of the central type (VMAT2). In addition, with double fluorescent IHC we detected VMAT1 protein in serotoninergic enterochromaffin cells (EC) of the stomach and in gastrin producing G cells of the antral mucosa. Similarly to the fundus, VMAT2 protein was present in ECL cells and in the enteric plexus. Surprisingly, serotonin- and/or histamine-containing cells in the connective tissue compartments of the stomach (i.e., lamina propria and submucosa), immunoreactive for a mast cell specific antigen, displayed neither VMATI nor VMAT2 immunoreactivity. Distribution of VMATs in the rat stomach support our previous observations on aminergic properties of two important gastrointestinal (GI) epithelial cell populations primarily known for other specific secretory products, i.e. dopaminergic properties of acid producing parietal cells and histaminergic properties of gastrin producing G cells. These data emphasize the existence of a non-neuronal, intrinsic aminergic system in the GI tract.     

Changes in mast cells after their exposure to constant electromagnetic field

By means of luminescent histochemistry effect of a constant magnetic field with induction 60 mTl (exposition for 2, 6, 36 h and 7 days) has been studied in order to reveal contents of catecholamines in mesenteric mast cells and in the intestinal mesentery cells in 50 white Wistar rats. In 2-6 h specific luminescence of the mast cells increases, however, at prolongation of the exposure up to 30 h metabolism of catecholamines in the mast cells is inhibited noticeably++ (luminescence disappears). In 8 days amount of the mast cells and specific luminescence of catecholamines decrease. The essential shifts revealed in the system of the mast cells of the mammalian should be taken into consideration in the magnetic-therapeutic practice. Close spatial relations between the mast cells and the mesenteric adrenergic terminals have been elucidated, demonstrating their morphofunctional interconnection.