RESUMO
The lack of immunological or morphological markers makes identification of immature mast cells difficult. In the present study we have used a rat mast cell specific monoclonal antibody (mAb AA4) to immunolabel mast cells during repopulation of the peritoneal cavity. Peritoneal cells were collected six days after injection of distilled water and examined by light and electron microscopy. mAb AA4 stained immature mast cells in various stages of maturation including a population of very immature mast cells that could not be identified using conventional staining methods. These cells had virtually no cytoplasmic granules and peripherally located lobated nuclei. Thus, immunolabeling with mAb AA4 has revealed a population of very immature mast cells not previously reported during repopulation of the peritoneal cavity.
Assuntos
Anticorpos Monoclonais/química , Mastócitos/citologia , Mastócitos/imunologia , Peritônio/citologia , Peritônio/imunologia , Animais , Especificidade de Anticorpos , Diferenciação Celular , Imuno-Histoquímica , Mastócitos/ultraestrutura , Microscopia Eletrônica , Microscopia de Fluorescência , Peritônio/ultraestrutura , Ratos , Ratos WistarRESUMO
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.
Assuntos
Mastócitos/citologia , Mesentério/citologia , Animais , Animais Recém-Nascidos , Divisão Celular , Feminino , Histocitoquímica , Masculino , Mastócitos/ultraestrutura , Microscopia Eletrônica , Ratos , Ratos WistarRESUMO
We have compared epidermal cell proliferation in skin biopsies from areas with lesions to contralateral areas without lesions in patients with indeterminate, tuberculoid and lepromatous leprosy. Cell proliferation was determined as the percentage of labeled cells in the basal and suprabasal epidermal layers, using autoradiographic preparations of skin biopsies taken 1 hr after a 3H-thymidine intradermal injection. We have found a significant reduction in epidermal cell proliferation in areas with lesions in the three groups of patients. The greatest reduction occurred in lepromatous patients. In lesions of patients with indeterminate or tuberculoid leprosy, the reduction was the same, and in both groups it was smaller than in lepromatous patients. In the areas without lesions, the index of labeled cells was similar to that of "normal" skin of nonleprosy patients. In the contralateral unaffected areas from leprosy patients and in "normal" skin from nonleprosy patients, as well as in affected areas from patients with indeterminate leprosy, epidermal cell labeling was greater in the suprabasal layer than in the basal layer. In lesions of lepromatous patients, cell labeling was greater in the basal layer than in the suprabasal layer. Our findings suggest that the reduction of epidermal cell proliferation in leprosy patients is restricted to the cell-mediated immune response, more intense in lepromatous leprosy. It does not seem to be related to denervation, which is greater in tuberculoid leprosy.
Assuntos
Epiderme/patologia , Hanseníase Virchowiana/patologia , Hanseníase Tuberculoide/patologia , Adulto , Divisão Celular , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Mast cells in the tongue of the bat (Artibeus lituratus) show a well-developed Golgi area and abundant mitochondria in the granule-free perinuclear cytoplasm. Rough endoplasmic reticulum profiles, free ribosomes, mitochondria, bundles of filaments and a great number of secretory granules are found throughout the remaining cytoplasm. The granules, of various shapes and sizes, are simple containing an electron-dense, homogeneous matrix, coarse particles or cylindrical scrolls, or combinations (cylindrical scrolls with either electron-dense, homogeneous matrix or coarse particle contents). Up to now, scroll-containing granules have been considered to be a unique feature of human mast cells.
Assuntos
Quirópteros/anatomia & histologia , Grânulos Citoplasmáticos/ultraestrutura , Mastócitos/ultraestrutura , Animais , Feminino , Humanos , Masculino , Língua/citologiaRESUMO
Acid phosphatase (AcP-A), trimetaphosphatase (TmP-A) activities and basic protein reaction were cytochemically studied in rat peritoneal mast cells 15 minutes after stimulation by compound 48/80. The AcPase reaction was positive in slightly altered granules, but negative in those more intensely altered, and also in unaltered granules. The TmP-A reaction was negative in altered granules and positive in a few unaltered granules. These results suggest that mast cells have two populations of granules, one, comprising most granules, is AcP-A positive and is exocytosed. The other, smaller, is TmP-A positive, and is not exocytosed. Intact granules gave a strong positive reaction with amoniacal silver nitrate (AS), which detects basic protein. This reaction decreased in intensity with increasing granule alteration.
Assuntos
Hidrolases Anidrido Ácido , Fosfatase Ácida/metabolismo , Exocitose , Mastócitos/metabolismo , Cavidade Peritoneal/citologia , Monoéster Fosfórico Hidrolases/metabolismo , Proteínas/metabolismo , Animais , Feminino , Concentração de Íons de Hidrogênio , Masculino , Mastócitos/enzimologia , Ratos , Ratos EndogâmicosRESUMO
Degranulation of rat mesentery mast cells by increasing concentrations of protamine causes a parallel decrease in the numbers of mast cells stained with toluidine blue or with berberine sulfate. No decrease in mast cell numbers occurs when degranulation is inhibited. Since protamine does not enter into non stimulated mast cells, these results suggest that this reduction in mast cell numbers is caused by the binding of protamine to the anionic sites of heparin of exocytosed granules thereby preventing their staining. There seems to be a competitive antagonism between protamine and toluidine blue at the anionic sites of heparin for increasing concentrations of toluidine blue progressively reverse the reduction in mast cell numbers.
Assuntos
Mastócitos/efeitos dos fármacos , Protaminas/farmacologia , Animais , Sítios de Ligação , Feminino , Heparina/metabolismo , Técnicas In Vitro , Masculino , Mastócitos/metabolismo , Ratos , Ratos Endogâmicos , Coloração e Rotulagem , Cloreto de TolônioRESUMO
The ammoniacal silver method, which identifies basic proteins, gives a positive reaction in cytoplasmic granules of rat peritoneal mast cells. However, in cytoplasmic granules of mucosal mast cells in the small intestine of the rat, this reaction is negative.
Assuntos
Mucosa Intestinal/análise , Mastócitos/análise , Peptídeos/análise , Animais , Grânulos Citoplasmáticos/enzimologia , Feminino , Mucosa Intestinal/enzimologia , Intestino Delgado , Masculino , Mastócitos/enzimologia , Peptídeo Hidrolases/análise , Ratos , Ratos Endogâmicos , Coloração e RotulagemRESUMO
Protamine stimulates guinea-mesenteric mast cells in a concentration-dependent manner, both histamine release and mast cell degranulation being correlated. Mast cell stimulation is blocked by 2,4-DNP (0.03 mM), low (0 degrees C) and high (45 degrees C) temperature. The inhibitory effect by 2,4-DNP is reversed by glucose (5.0 mM), while incubation at 37 degrees reverses that by low and high temperature. Lack of calcium from the incubation medium does not influence mast cell stimulation by protamine. However calcium chelation with EDTA (2.0 mM) or EGTA (2.0 mM) blocks mast cell stimulation. Addition of calcium (0.9 mM) reverses this inhibition. These observations indicate that guinea-pig mast cell stimulation by protamine is a nonlytic, energy and calcium dependent process, similar to anaphylaxis, but different from that of other basic compounds which induce mast cell lysis.
Assuntos
Mastócitos/fisiologia , Mesentério/citologia , Protaminas/farmacologia , 2,4-Dinitrofenol , Animais , Cálcio/farmacologia , Grânulos Citoplasmáticos/efeitos dos fármacos , Grânulos Citoplasmáticos/fisiologia , Dinitrofenóis/farmacologia , Ácido Edético/farmacologia , Ácido Egtázico/farmacologia , Feminino , Cobaias , Liberação de Histamina/efeitos dos fármacos , Magnésio/farmacologia , Masculino , Mastócitos/efeitos dos fármacosRESUMO
1. Verapamil (1.0 microM) inhibits histamine release from rat peritoneal mast cells induced by both compound 48/80 (Burroughs Wellcome), an external calcium-independent stimulant, and by protamine, an external calcium-dependent stimulant. 2. The inhibition was reversed by calcium in a concentration-dependent manner and thus seems to be related to the calcium-blocking action of verapamil. The inhibitory effect of 1.0 microM verapamil on protamine-induced histamine release in the presence of 0.5 mM calcium was 64%, and 32% in the presence of 2.0 mM calcium. 3. At concentrations of 0.1-1.0 mM, verapamil induces histamine release. The verapamil-induced release was independent of calcium at lower concentrations but at 1.0 mM, more release was observed in the absence of calcium. Histamine release induced by verapamil was blocked by temperature (2-4 degrees C) and by 2,4-dinitrophenol. Glucose (5 mM) reversed the effect of 2,4-dinitrophenol.