Polak, J.M. (Julia M.)
- Publications
- item.page.relationships.isContributorAdvisorOfPublication
- item.page.relationships.isContributorOfPublication
9 results
Search Results
Now showing 1 - 9 of 9
- Nitric oxide synthase-immunoreactive neurons in human and porcine respiratory tract(Elsevier, 1993) Springall, D.R. (David R.); Polak, J.M. (Julia M.); Villaro, A.C. (Ana Cristina); Montuenga-Badia, L.M. (Luis M.); Diaz-de-Rada, O. (O.); Martinez, A. (Alfredo)The presence of nitric oxide synthase (NO-synthase), the enzyme responsible for the production of nitric oxide (NO) from L-arginine, is shown immunocytochemically in the intrinsic neurons of the human and porcine respiratory tract. NO-synthase immunoreactivity is demonstrated in a subpopulation of neurons of the microganglia present in the wall of the extra- and intrapulmonary bronchi as well as in the hilar region of the lung in relation to blood vessels. The immunostaining was also found in some nerve fibers of the respiratory nervous system. Human and porcine lung gave similar results. The possible involvement of NO in the nonadrenergic noncholinergic (NANC) nervous regulation of the lung is discussed.
- Distribution of peptidyl-glycine alpha-amidating mono-oxygenase (PAM) enzymes in normal human lung and in lung epithelial tumors(Sage Publications, 1996) Springall, D.R. (David R.); Polak, J.M. (Julia M.); Montuenga-Badia, L.M. (Luis M.); Saldise, L. (Laura); Vazquez, J.J. (Jesús Jaime); Treston, A.M. (Anthony M.); Martinez, A. (Alfredo)C-terminal alpha-amidation is a post-translational modification necessary for the biological activity of many regulatory peptides produced in the respiratory tract. This modification is a two-step process catalyzed by two separate enzyme activities, both derived from the peptidyl-glycine alpha-amidating mono-oxygenase (PAM) precursor. The distribution of these two enzymes, peptidyl-glycine alpha-hydroxylating monoxygenase (PHM) and peptidyl-alpha-hydroxyglycine a amidating lyase (PAL), was studied in the normal lung and in lung tumors using immunocytochemical methods and in situ hybridization. In normal lung the enzymes were located in some cells of the airway epithelium and glands, the endothelium of blood vessels, some chondrocytes of the bronchial cartilage, the alveolar macrophages, smooth muscle cells, neurons of the intrinsic ganglia, and in myelinated nerves. A total of 24 lung tumors of seven different histological types were studied. All cases contained PAM-immunoreactive cells with various patterns of distribution. All immunoreactive cells were positive for the PHM antiserum but only some of them for the PAL antiserum. The distribution of PAM co-localizes with some other previously described amidated peptides, suggesting that amidation is an important physiological process taking place in the normal and malignant human lung tissue.
- Localization of amidating enzymes (PAM) in rat gastrointestinal tract(Histochemical Society, 1993) Kuijk, M. (Marjolein); Polak, J.M. (Julia M.); Burrell, M.A. (María Ángela); Montuenga-Badia, L.M. (Luis M.); Cuttitta, F. (Frank); Treston, A.M. (Anthony M.); Martinez, A. (Alfredo)We studied the distribution of the two enzymes involved in post-translational C-terminal alpha-amidation of regulatory peptides in rat digestive tract, using immunocytochemical methods and in situ hybridization techniques. The enzymes were located in most of the fibers and neurons of the myenteric and submucous plexus throughout the entire digestive tract and in endocrine cells of the stomach and colon. Staining of reverse-face serial sections demonstrated that the enzymes in endocrine cells of the stomach co-localized with gastrin in the bottom of the gastric glands. Some gastrin-immunoreactive cells near the neck of the gland were negative for PAM, suggesting that amidation takes place only in the more mature cells. In the colon all cells immunoreactive for glucagon and GLP1 were also positive for peptidylglycine alpha-hydroxylating monooxygenase (PHM) but not for peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL). The absence of immunoreactivity for the amidating enzymes in endocrine cells of the small intestine, known to produce C-terminally amidated peptides, suggests the existence of other amidating enzymes.
- CGRP-immunoreactive endocrine cell proliferation in normal and hypoxic rat lung studied by immunocytochemical detection of incorporation of 5'-bromodeoxyuridine(Springer Verlag, 1992) Springall, D.R. (David R.); Taylor, K.M. (K.M.); Winter, R.J.D. (R.J.D.); Zhao, L. (L.); Barer, G. (G.); Polak, J.M. (Julia M.); Montuenga-Badia, L.M. (Luis M.); Gaer, J. (J.); McBride, J.T. (J.T.)We have tested the suggestion that the reported increase, in hypoxic rats, in the number of lung endocrine cells immunoreactive for the regulatory peptide CGRP is caused by an accumulation of peptide within the cells which renders them more detectable, rather than by a real increase in proliferation. The incorporation of continuously infused 5'-bromodeoxyuridine (BrdU) into nuclei of CGRP-containing cells was studied by immunohistochemistry in the airway and respiratory epithelium of rats kept in a hypoxic (10% O2), normobaric conditions for 7 days and in normoxic, normobaric controls. Some CGRP-immunoreactive cells could also be labelled for BrdU. However, the ratio of the number of cells labelled with both CGRP and BrdU to the number of cells labelled with CGRP alone did not differ significantly between hypoxic and normoxic rats (7.1 +/- 0.7 and 6.1 +/- 1.2, respectively; mean +/- SEM; P = 0.49). These data strongly suggest that CGRP-containing endocrine cells or their precursors do proliferate in adult rat lung, but that the proliferation is not increased significantly in hypoxia.
- Immunohistochemical colocalization of 7B2 and 5HT in the neuroepithelial bodies of the lung of Rana temporaria(Springer Verlag, 1993) Sesma, M.P. (María Pilar); Polak, J.M. (Julia M.); Montuenga-Badia, L.M. (Luis M.); Bodegas-Frías, E. (Elena)The neuroendocrine cell population of the lung of Rana temporaria has been studied by means of immunocytochemistry. Serotonin (5HT)- and polypeptide 7B2-immunoreactive neuroepithelial bodies have been observed in the epithelial lining of the lung. 5HT- but not 7B2-immunoreactive isolated endocrine cells have also been observed.
- Simultaneous immunostaining method for localization of bromodeoxyuridine and calcitonin gene-related peptide(Histochemical Society, 1992) Springall, D.R. (David R.); Polak, J.M. (Julia M.); Montuenga-Badia, L.M. (Luis M.); Gaer, J. (J.); McBride, J.T. (J.T.)A new simultaneous double immunostaining method has been optimized to localize the DNA synthesis marker bromodeoxyuridine (BrdU) and calcitonin gene-related peptide (CGRP) in endocrine cells of Bouin's-fixed, paraffin-embedded rat lung. Nuclease pre-treatment before immunostaining is compatible with optimal tissue morphology and CGRP antigenicity preservation. Nickel-enhanced development of avidin-biotin-peroxidase staining is used to show CGRP immunoreactivity in black and alkaline phosphatase-anti-alkaline phosphatase is applied to demonstrate incorporated BrdU in red. The present methodology could be useful for studies requiring detection of incorporated BrdU in cells producing regulatory peptides or other labile antigens.
- Immunocytochemical localization of peptidylglycine alpha-amidating monooxygenase enzymes (PAM) in human endocrine pancreas(Histochemical Society, 1993) Springall, D.R. (David R.); Polak, J.M. (Julia M.); Montuenga-Badia, L.M. (Luis M.); Cuttitta, F. (Frank); Treston, A.M. (Anthony M.); Martinez, A. (Alfredo)We studied the distribution of the enzymes that are involved in the post-translational alpha-amidation of regulatory peptides in human endocrine pancreas, using immunocytochemical methods for light and electron microscopy. Immunoreactivity for the two enzymes involved, peptidylglycine alpha-hydroxylating monooxygenase (PHM) and peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL), was located in the periphery of the islets of Langerhans and in ductal endocrine cells. Staining of reverse-face serial sections demonstrated that these immunoreactivities co-localize with glucagon but not with pancreatic polypeptide (PP), insulin, or somatostatin. Double immunogold staining for electron microscopy confirmed the previous results and revealed a different localization for each enzyme inside the secretory granule: PHM is present in the central core of the glucagon-containing granules, whereas PAL is predominantly located near the granule membrane. The existence of an amidated peptide, GLP1, in the A-cells explains the presence of peptidylglycine alpha-amidating monooxygenase enzymes (PAM) in these cells. The absence of the enzymes in the PR-cells raises the possibility that a different form of amidating enzyme may be involved in the post-translational processing of this peptide.
- Endothelin-like immunoreactivity in midgut endocrine cells of the desert locust, Locusta migratoria(Elsevier, 1994) Sesma, M.P. (María Pilar); Springall, D.R. (David R.); Polak, J.M. (Julia M.); Prado, M.A. (M.A.); Montuenga-Badia, L.M. (Luis M.)Endothelin-1-like immunoreactivity has been found in endocrine cells of the midgut of the desert locust Locusta migratoria. Several antisera have been directed against the whole molecule and its C-terminal sequence. Endothelin-1-immunoreactive cells are present in the main region of the midgut (ventriculus) and in the midgut caeca but not in the ampullae through which the malpighian tubules drain. Endothelin-1-like immunoreactivity colocalizes with FMRFa immunoreactivity in the cells of the main region of the midgut but not in those in the midgut caeca. Endothelin-1-immunoreactive cells are present not only in adults but also throughout the five instars of posthatching development.
- A novel granular cell type of locust Malpighian tubules: ultrastructural and immunocytochemical study(Springer Verlag, 1992) Sesma, M.P. (María Pilar); Polak, J.M. (Julia M.); Villaro, A.C. (Ana Cristina); Prado, M.A. (M.A.); Montuenga-Badia, L.M. (Luis M.); Etayo, J.C. (Juan Carlos)A novel secretory cell type in the initial segment of the Malpighian tubules of the locusts Schistocerca gregaria and Locusta migratoria is described ultrastructurally and studied by means of immunocytochemical techniques. The cells show abundant rough endoplasmic reticulum with interspersed Golgi zones. The richness of the cell secretory machinery and the presence of apical dense pleomorphic granules suggest a role in secretion of proteinaceous material to the tubule lumen. The surprising finding of ACTH (1-24)-, ~-MSH-, and 7B2-1ike immunoreactivity for this cell is discussed.