Induction of fluorescence in histamine-containing cells

Methods in neuroendocrine histopathology, a methodological overview

Light microscopy is still the main tool in diagnostic histopathology, though it does not always lead to a definitive diagnosis. It has therefore been a constant ambition to develop methods which can add further information to the diagnosis. In endocrine pathology, a major problem has been to distinguish between neuroendocrine and non-neuroendocrine tumours. The silver stains, such as the Bodian, Grimelius and Sevier-Munger methods, were the first useful "general neuroendocrine" markers. Electron microscopy can also be useful for identifying neuroendocrine tumours. A further step forward was the introduction of histochemical fluorescence methods, as these could identify biogenic amines. With the introduction of immunohistochemical techniques, tumours could be characterized in a more specific way regarding peptide hormones and biogenic amines content, proliferation factors, hormone receptors, etc. Another method, DNA cytometry, has been used mainly in predicting the prognosis. In situ hybridization can be a useful complement to the histopathological diagnosis when other methods have failed to demonstrate the neuroendocrine nature of the tumour. Some endocrine tumours, especially the well-differentiated ones, still cause diagnostic problems in predicting tumour behaviour, why further complementary methods would be of great value.

Mast cell maturation in young rats: a histofluorescence and cytochemical study

Since they are not submitted to experimental alterations new-born rats are useful for the investigation of mast cell maturation and were therefore analysed in the present study. In the mesentery of new-born rats immature mast cells were present within and close to fat sheaths containing blood vessels. On day 15, mast cells were also found in mesentery windows and generally in a more advanced stage of maturation. On day 30, the distribution and maturation of mast cells were similar to those found in adult rats. In new-born rats, immature mast cells contained a few metachromatic granules, which showed a positive fluorescence after berberine sulfate staining for heparin and after exposure to paraformaldehyde for serotonin detection. Orthophthaldialdehyde-induced fluorescence for histamine demonstration was negative. On day 15, heparin and serotonin fluorescence were increased and histamine fluorescence became positive. Electron microscopically most mesentery immature mast cells of new-born rats had a well developed Golgi apparatus and rough endoplasmic reticulum, numerous mitochondria and an indented nucleus. The few cytoplasmic granules were large and some of them showed a positive trimetaphosphatase reaction in their periphery. On day 15, most mast cells were almost full of granules. On day 30, mast cells could not be distinguished from those in adult rats. These results show that mast cell maturation in young rats differs from that in adult animals after peritoneal distilled water injection.

Localization and quantification of histamine in injured skin as parameters for the timing of wounds

Localization and estimation of the histamine (HA) content in skin wound edges in 86 Sprague-Dawley rats and three cases of human injuries were carried out by a microfluorimetric method specific for this amine which forms a complex with o-phthalaldehyde (OPT). Distribution and density of the mast cells in the same areas were observed at the same time by toluidine blue stain. In all skin specimens with antemortem wounds, both the epidermis and upper dermis exhibit extracellular yellowish fluorescence of the HA-OPT complex. The fluorescent zone spreads in the wound edges with the lapse of time in vital injuries. The HA content increases gradually up to 30 min and then the yellow histamine fluorescence in areas 0-200 microns from the wound edge decreases. None of these features can be observed in normal skin and postmortem-injured skin. Mast cell degranulation can be demonstrated in all antemortem-injured skin. No statistical relationship exists between the number of mast cells and the HA-OPT fluorescence in either ante- or postmortem-injured groups. This study indicates that skin HA microfluorimetry by the OPT method is of practical value for distinguishing ante- from the postmortem wounds and for timing antemortem wounds.

Immunocytochemical localization of histamine in flatworms

Specific antibodies against histamine were used to demonstrate the occurrence and cellular distribution of histamine-like immunoreactivity in three species of flatworms (phylum Platyhelminthes). In the parasitic cestode Diphyllobothrium dendriticum, histamine-reactivity was found in neurons of the main nerve cords, and in cells lining the central and peripheral excretory ducts. In the free-living microturbellarian Microstomum lineare and in the planarian Polycelis nigra, histamine-immunoreactivity was restricted to cells and fibres of the nervous system. The occurrence of histamine or a related substance in the nervous system of flatworms, which represent primary bilateria, indicates the importance of this neuroactive substance in the animal kingdom.

Murine basophil-mast differentiation: toward optimal conditions for selective growth and maturation of basophil-mast or allied cells

Recent investigations revealed that basophil-mast cells were related to the hemopoietic system. Strikingly, murine bone marrow showed a singular paucity in cells with basophil-mast features; moreover in clonogenic assays (methylcellulose, agarose) bone marrow was found to be manifestly poor in basophil-mast progenitor cells. Our work brought to light several new facts concerning the culture and differentiation of this cell type: 1 degree pure and mixed mast clones can be derived in large numbers from bone marrow, provided progenitors are cultured in collagen matrix. Up to 1,382 hemopoietic clones were analysed in situ after staining: 30% contained mast cells (34 per 10(5) cells), thus the basophil-mast lineage was one of the most frequent. We concluded that other cloning media were noticeably nonoptimal for the growth and/or maturation of mast cells. We suggested that collagen and the molecular edifices derived from it, both found in variable amounts in the natural mast environments, should play essential roles in mast phenotype expression. 2 Degrees cholera toxin (CT) selectively eradicated nonmast progenies: mast progenitors and mast progenies were resistant. In this way, pure and rapidly expanding mast cell clones were obtained at a frequency never reported before. CT possibly acts both directly, as a stimulator of mast cell proliferation, or indirectly on marrow subpopulations which repress basophil-mast cell growth and maturation. In vitro culture conditions, specifically designed for basophil-mast lineage, should prove of interest in the search for an unifying hypothesis concerning the multiple forms of mast cells found in various tissues.

Schistosoma mansoni: neurotransmitters and the mobility of cercariae and schistosomules

The concentration-dependent action of alkyl-isothiouroniums on Schistosoma mansoni cercariae, ranging from partial to total abolition of locomotor and flame cell movements, and/or suppression of virulence, is due to H1-histamine receptor inhibition. Correspondingly, H1-receptor inhibitors of widely different chemical structure, such as clemizol, diphenhydramine, brompheniramine, and promethazine, in 0.03-0.06 nM concentrations, induced an analogous cercarial immobilization reversed by addition of excess histamine. In contrast, the H2-receptor inhibitors cimetidine and metiamide did not immobilize cercariae. Histamine, acetylcholine, and serotonin, added to cercarial suspensions, showed no direct activity. Their participation in the mechanism of cercarial mobility was shown by the dose-dependent effects of antagonists, such as the serotonin antagonist methysergide and the acetylcholinesterase inhibitor physostigmine. These effects were not reversible by addition of serotonin and acetylcholine, respectively. A histamine-irreversible cercarial immobilization induced by the H-liberator 48/80 suggested that, besides H1-receptor inhibition, H-liberation and/or depletion also participated in mobility and survival. The detection of histamine in the cercaria corroborated the participation of histaminergic mechanisms. S. mansoni schistosomules collected from the mouse lung reacted to H1 antihistamines like cercariae, with a dose-dependent reduction of mobility and somatic deformation, such as vacuolization, granulation, and caecal enlargement.

Mast cells in rat thalamus: nuclear localization, sex difference and left-right asymmetry

Mast cells were positively identified in rat brain by a combination of staining and histochemical procedures. These cells stained positively with toluidine blue and Astrablau at low pH, indicating the presence of a proteoglycan similar to that found in peripheral mast cells. Brain mast cells also fluoresced after o-phthalaldehyde exposure, indicating that they contain histamine. Mast cells varied greatly in number among brains, but their distribution was almost exclusively thalamic; within thalamus, the ventral complex, medial dorsal, lateral, and paraventricular nuclei contained the most mast cells. Mast cell numbers were greater in brains of females than of males, and greater in left than in right hemispheres. These findings suggest that mast cells have a specialized function in thalamus and/or that the vascular environment of the thalamus is particularly conducive to mast cell accumulation.

Histamine-containing neurons in the rat hypothalamus

A specific antiserum against histamine was produced in rabbits, and an immunohistochemical study of histamine-containing cells was carried out in rat brain. The antiserum bound histamine in a standard radioimmunoassay and stained mast cells located in various rat and guinea pig tissues. Enterochromaffin-like cells in the stomach and neurons in the posterior hypothalamic area could be detected with this antiserum. The staining was highly specific and was not abolished by preabsorption with histidine, histidine-containing peptides, serotonin, or catecholamines, whereas preabsorption with histamine completely abolished the staining. Immunoglobulins of this antiserum purified by affinity chromatography stained the same cells as did the crude antiserum, whereas the serum fraction, which was not absorbed by histamine-affinity ligand, failed to stain any neuron. Histamine-immunoreactive neuronal cell bodies were found only in the hypothalamic and premammillary areas of colchicine-treated rats. The largest group of cells was seen in the caudal magnocellular nucleus and medially on the dorsal and ventral aspects of the ventral premammillary nucleus. Immunoreactive nerve fibers, but no cell bodies, were detected in other parts of the brain. Histamine-immunoreactive mast cells were found in the median eminence and pituitary gland. The results suggest that histamine-containing neurons are located only in a small area of the posterior hypothalamus, and these cells are probably the source of ascending and descending fibers detected in other brain areas.

Fluorescence histochemical methods for the study of peptide hormone-producing cells

Fluorescence histochemical methods for the demonstration of specific residues in peptides and proteins are reviewed: Formaldehyde-ozone for NH2-terminal tryptophan, formaldehyde-HCl for tryptophan regardless of position in the peptide, OPT for NH2-terminal histidine, formaldehyde-fluorescamine for "protected" amino groups, nitroso-naphthol for tyrosine, and phenanthrenequinone for arginine residues. The methods are potent in demonstrating granule-stored material in peptide hormone-producing cells. Also quinacrine, the fluorescent anti-malaria agent, binds to granular components, as yet unidentified, in several endocrine cell types. In many cases the fluorescence histochemical methods seem to demonstrate peptides and proteins distinct from the known hormones.

Polyamine cytochemistry. Use of a novel o-phtalaldehyde method for visualizing spermidine and spermine. Comparisons to the formaldehyde-fluorescamine method

o-Phtalaldehyde (OPT) reacts with a number of biologically important molecules, including the polyamines, spermidine and spermine. By systematically varying reaction conditions with respect to temperature, pH, concentration and length of exposure to the reagent, using both model systems and tissues, we have succeeded in constructing a cytochemical OPT-method specific for spermidine and spermine. The method detects cell types known to contain these polyamines, including growing and neoplastic cells. The staining pattern obtained with the OPT method is identical to that obtained with the formaldehyde-fluorescamine (FF) technique recently shown to be specific for spermidine and spermine. In contrast to the FF technique, the OPT method can be used for staining suspensions of isolated cells and may hence be employed in studies using fluorescence-activated cell sorting (FACS). Preliminary such studies show a pronounced decrease in cellular OPT-induced fluorescence, paralleled by a decrease in content of polyamines, after treatment with the polyamine biosynthesis inhibitor alpha-difluoromethylornithine (alpha DFMO). In contrast, cells simultaneously treated with alpha DFMO + spermidine show pronounced increases in their spermidine content and parallel increases in their OPT-induced fluorescence. Availability of methods selectively demonstrating polyamines at the cellular and subcellular level is expected to aid our understanding of polyamine functions in normal growth and cancer.

A putative role for eosinophils in tick rejection

In the reaction of Bos taurus cattle to infestation by the tick Boophilus microplus, mast cell histamine is translocated by the eosinophils to the attachment site. The concentration pattern of this cutaneous mediator for pain appears related to the grooming behaviour of the host.

Cytochemical detection of histamine in the human granulopoietic series of healthy subjects and of patients affected by chronic myeloid leukaemia. A spectrophotofluorimetric test for checking OPT-induced fluorescence in isolated cells

Cellular histamine in blood and bone marrow has been identified histochemically using an o-phthaldialdehyde fluorescence reaction. The specificity of the reaction was tested by a spectrofluorometric analysis of cell extracts. In normal blood, the basophils emit a bright yellow fluorescence, whereas neutrophils, eosinophils and platelets react less consistently and when they do, they give off a less intense yellow or blue emission. In normal marrow, basophils react strongly whereas the metamyelocytes and later granular cells show only a weak yellow or blue fluorescence. In chronic myeloid leukaemia, cells of the granular series emit a strong yellow fluorescence at all stages of development, although still less intense than the basophils. During remission, the fluorescence pattern of cells from leukaemic subjects reverts to that of normal cells.

Requirement for vasoactive amines for production of delayed-type hypersensitvity skin reactions

The skin sites of the mouse where delayed-type hypersensitivity (DTH) reactions are most easily elicited (foot pads and ears) are particularly rich in 5-hydroxytryptamine (5-HT)-containing mast cells. Since mice are deficient in circulating basophils, which play a role in at least some DTH reactions, we investigated the possibility that the mast cells were playing an important role in the evolution of the skin reactions of DTH in mice. We found that reserpine, a drug which depletes mast cells of 5-HT, abolished the ability of the mouse to make DTH reactions in the skin. The suppressive effect of reserpine could be partially blocked by monoamine oxidase inhibitors which prevent the degradation of 5-HT in the cytosol of the mast cell. Spleen cells of immune, reserpine-treated mice transferred DTH reactions to nonimmune mice normally, indicating that the reserpine treatment did not affect immune T cells. DTH reactions could not be transferred into reserpine-treated mice. We suggest that T cells are continually emigrating from the blood, through postcapillary venule endothelium, by a mechanism which does not depend on vasoactive amines. If they are appropriately immune and meet the homologous antigen in the tissue, they induce mast cells to release vasoactive amines which cause postcapillary venule endothelial cells to separate, allowing the egress from the blood of cells which ordinarily do not recirculate. The secondarily arriving vasoactive amine-dependent cells are responsible for the micro- and macroscopic lesions of DTH reactions. Chemotactic factors may also be involved in bringing cells to the DTH reaction sites but we propose that T-cell regulation of vasoactive amine-containing cells allows the effector cells to pass through the endothelial gates after they are called.

The role of the antrum and the vagus nerve in the formation of gastric mucosal histamine

1. The effects of the vagus nerve and of antral gastrin on the rate of histamine formation (histamine forming capacity, HFC, i.e. histidine decarboxylase activity) in the parietal cell region of the gastric mucosa has been investigated in the following stomach preparations: gastric fistula, denervated Heidenhain pouch, antral resection with gastrojejunostomy, gastrojejunostomy with exclusion of the duodenum and in the intact stomach. The determinations of mucosal HFC were made on fasting rats and on re-fed animals when the effect of feeding was studied.2. In fasting rats with a gastrojejunostomy and the antrum intact the mucosal HFC of the innervated stomach was about 4 times higher than in the corresponding preparation with the antrum resected. In the innervated main stomach the mucosal HFC was about twice as high as in the denervated pouch, indicating that the vagus and endogenous antral gastrin each contribute to maintaining mucosal HFC in the fasting state.3. Acidifying the stomach caused a substantial lowering of the mucosal HFC presumably by inhibiting antral gastrin release, whereas acid in the stomach did not interfere with the elevation of mucosal HFC evoked by injection of gastrin.4. Injection of gastrin elevated mucosal HFC in the innervated main stomach and in the denervated pouch to approximately equal levels. With the dose of gastrin employed there was about a fourfold increase in the HFC of the pouch mucosa.5. In antrectomized rats enhanced vagal influence, evoked by insulin injection or by feeding, raised the mucosal HFC. In rats with the antrum intact and the stomach acidified, insulin injection produced an increased HFC. Thus, a vagal effect on mucosal HFC exists independent of participation of antral gastrin.6. The stable choline esters carbachol and methacholine act directly on the parietal cell without involving mucosal HFC. The vagus nerve and gastrin, however, are assumed to provide secretory stimulation by means of accelerated histamine formation.7. The interrelation between increased histamine formation and hydrochloric acid secretion is discussed.