Károly Altdorfer

Neuroimmune interactions in experimental colitis: An immunoelectron microscopic study

With its abundance of neurons and immunocytes, the gut is a potentially important site for the study of the interaction between the nervous and immune systems. In this electron microscopic study we have investigated the distribution of substance P (SP)- and vasoactive intestinal polypeptide (VIP)-immunoreactive (IR) nerve terminals and the immunocytes during experimental colitis in the rat. A mild colitis was induced by a luminal enema containing trinitrobenzene sulfonic acid. The most severe inflammation was detected after 2 days and the density and the distribution of the SP- and VIP-IR nerve terminals as well as the immunocompetent cells were studied at that time. Many SP- and VIP-IR nerve terminals were observed in a very close situation to the inflammatory cells. The number of VIP-IR nerve terminals slightly increased in the inflamed area. The gap between the axolemma of the nerve terminals and immunocytes was 20–200 nm. Some lymphocytes and plasma cells were also IR for SP in the inflamed area, whereas no IR immunocytes were observed in the control and in noninflamed area from the same animal. The very close apposition of the SP- and VIP-IR nerve terminals to the inflammatory cells as well as the presence of SP-IR immunocytes in inflamed area support the suggestion that bidirectional neuroimmunomodulation exists in the colon.

Neuroimmune Link in the Mucosa of Chronic Gastritis with Helicobacter pylori Infection

It is suggested that different neuropeptides regulate gastric mucosal integrity and participate in the development of chronic gastritis. The aim of this study was to examine the roles and changes of immunoreactive (IR) nerves and immunocompetent cells in human gastritis. Immunohistochemical, immunocytochemical, and confocal laser microscopic methods were used. All investigated nerve fibers were found in different quantities in the mucosa of both control and gastritis samples. The number of SP, NPY, and VIP IR nerve fibers increased significantly (P < 0.05) in gastritis. No IR immunocompetent cells (lymphocytes, plasma cells, mast cells) were found in the control, however, some showed NPY (16.8%) and SP (9.4%) immunoreactivity in chronic gastritis. The distance between nerve fibers and immunocompetent cells was 200 nm to 1 μm. In conclusion, the increased number of SP, NPY, and VIP IR nerves and IR immunocytes suggests that they participate in development of neurogenic inflammation, repairing processes of chronic gastritis.

Correlation and immunolocalization of substance P nerve fibers and activated immune cells in human chronic gastritis

Neuropeptides are able to modulate cytokine production by macrophages in response to various stimulators and have a major role in inflammation of different organs. Mammalian poly (ADP‐ribose) polymerase (PARP) and nuclear factor kappa B (NF‐κB) both have been suggested to play a crucial role in inflammatory disorders. Unregulated increase of tumor necrosis factor‐α (TNF‐α) may also be pathogenic in inflammatory diseases. The aim of this study was to investigate the correlation between the number of Substance P (SP) containing nerve fibers and activated immune cells using immunohisto‐, immunocytochemical (EM) and confocal laser microscopic methods. To investigate expression and activation of immune cells gastric biopsy samples from patients with chronic gastritis were used. The number of SP containing nerve fibers and activated immune cells increased significantly in gastritis. Using monoclonal p65 antibody, activated NF‐κB was found in inflamed mucosa but was absent in uninflamed mucosa. Immunobinding for the activated form of p65 of NF‐κB was found in 22% of macrophages and 45% of lymphocytes. The number of immune cells showing IR for NF‐κB, PARP and TNF‐α correlated with the increasing number of SP containing fibres. Confocal laser microscopy was used to confirm the colocalization of SP in TNF‐α and NFκB positive lymphocytes and mast cells in inflamed mucosa. Immunoelectronmicroscopic investigation confirmed that these cells belong to lymphocytes, mast cells and macrophages. Conclusions: The increase of SP in nerve fibers and in activated immune cells further activate the production of other proinflammatory mediators (e.g. TNF‐α) and therefore generate the chronic inflammation. Anat Rec, 291:1140–1148, 2008.

Nitric oxide synthase immunoreactivity of interstitial cells of Cajal in experimental colitis

Abstract.Objective: There is functional and morphological evidence that interstitial cells of Cajal (ICC) may play a role in nitric oxide (NO) dependent signal transduction. However, little is known about the nitric oxide synthase (NOS) containing ICC during inflammation.¶Materials and Methods: Immunocytochemical methods were used for the ultrastructural localization of NOS1-containing ICC in the wall of the colon of rats in experimental colitis.¶Results: Large numbers of NOS immunoreactive (IR) nerve terminals were found in very close vicinity to smooth muscle cells as well as to blood vessels. IR nerves were found in close relationship with the ICC. The gap between the NOS IR nerve fibers and the membrane of smooth muscle cells and of ICC was 20–250 nm. In experimental colitis the number of NOS IR nerve fibers slightly decreased, however, large numbers (24%) of the ICC became IR for NOS. In the noninflamed area and in the controls, all these cells were immunonegative for NOS.¶Conclusions: Our light- and ultrastructural study suggests that some of the ICC can also synthesize NO, at least during inflammation. Therefore the change in the number and structure of ICC could play an important role in the pathogenesis of a variety of motility disorders.

Nitric oxide synthase-containing nerve elements in the pylorus of the cat

Combined nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry, nitric oxide synthase (NOS) and vasoactive intestinal polypeptide (VIP) immunocytochemistry were used to study the distribution of NOS- and VIP-containing nerve elements in the feline pylorus. A large number of stained multipolar neurons was found in the myenteric plexus. However, some NADPH-d and NOS positive neurons were also observed in the submucous plexus and in the internal part of muscular layer. A few stained perikarya were found in the tunica mucosa, in a very close situation to the blood vessels. A large number of thin varicose fibres, with intense reaction for all markers were seen around or in close contact with the unstained perikarya to the blood vessels and some of them around the pyloric glands. The density of NOS and NADPH-d positive nerve elements was much higher than that of VIP-immunoreactive (IR) nerve elements. Our results suggest that nitric oxide (NO) might act as a regulatory neurotransmitter of the pyloric sphincter, blood flow and secretion in this region.

Distribution and possible origin of neuropeptide-containing nerve elements in the mammalian liver.

The intrahepatic distribution of nerve fibres is highly species dependent, therefore we searched for a species where the innervation pattern is similar to that of the human liver. Livers of rats, cats, guinea pigs and humans were used. The different nerve elements were identified by ABC immunohistochemistry and analysed semiquantitatively. Large numbers of neuropeptide Y (NPY) and dopamine-beta-hydroxylase immunoreactive (IR) nerve fibres were observed in the human and guinea pig liver, and they were in close contact with portal triads, central veins and ran parallel with liver sinuses. A few substance P, somatostatin and vasoactive intestinal polypeptide IR nerve fibres were also detected intralobularly, while galanin nerve fibres were only observed around portal triads. In the rat liver only a few NPY-positive nerve fibres were found, exclusively in portal tracts. Some nerve cell bodies (IR for NPY and somatostatin) were also found in the liver of guinea pigs, young cats and humans, therefore some of the nerve terminals might originate from these intrinsic ganglia. It can be concluded that the innervation pattern of the guinea pig liver shows the highest similarity to that of the human liver.

Neuropeptide analysis of oral mucosa in diabetic rats

Objective: Increasing evidence indicates that different neuropeptide-containing nerve elements are involved in the immune system and influence the inflammation of the gastrointestinal tract. The aim of this study was to investigate the morphological localization and distribution of the different immunoreactive (IR) nerve fibers and immunocompetent cells in the oral mucosa (e.g. tongue, gingiva) and compare the results with data received from streptozotocin (STZ)-induced diabetic rats. Materials and Methods: The different nerve elements and immunocytes were detected by ABC immunohistochemistry. Results: The IR nerve fibers were found in the tunica propria of oral mucosa with different densities. These IR nerve fibers were mainly located beneath the epithelial lining, around the blood vessels and glands, and some of them were also located in the taste buds. After 2 weeks of STZ treatment the total number of IR nerve fibers, especially the SP and neuropeptide Y (NPY) IR ones, was significantly increased (p < 0.05), as was also the number of immunocytes (lymphocytes, plasma cells, mast cells). Some of these cells also showed immunoreactivity for substance P (SP) and NPY. In several cases the SP IR nerve fibers were found in close proximity to the immunocytes. Electron microscopic investigation also revealed the close association between the IR nerve fibers and immunocompetent cells where the gap was 1 µm or even less. Conclusions: The close anatomical associations suggest communication between nerve fibers and immune cells which can be crucial for maintaining mucosal homeostasis and for ensuring an appropriate response to injury.

Morphological evidence of local reflex arc in the rat's tongue.

Lingual components of the autonomic nervous system are considered to be the most rostral portion of the enteric nervous system. Therefore our aim was to study the intrinsic nerve cell bodies and synapses using immunohisto-, immunocytochemical methods. Several small groups of ganglia with cell bodies immunoreactive (IR) for vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) and substance P (SP) were observed just below the gustatory epithelium. A few somatostatin and galanin IR nerve cell bodies were also found. Many IR cell bodies were also demonstrated in the glands and next to blood vessels. Some of these cell bodies were multipolar and some of them were small neurons with an ovoid shape having only one process. Cell bodies positive for calcitonin gene-related peptide (CGRP) were detected neither in the superficial nor in the deep portion. Electronmicroscopical analysis demonstrated different IR nerve fibres having axo-somatic and axo-dendritic synapses with other immunonegative cells. In a few cases VIP IR nerve processes were found to synaptize with other VIP positive nerve cell bodies. These results support the existance of intralingual reflex in the tongue, where the ganglia might have an integrative role of the different neuropeptide containing nerve fibres.

Changes in the innervation of the taste buds in diabetic rats

Bevezetes: A diabetes mellitusban szenvedő betegek 10%-a koros erzesről panaszkodik, amelyek kozott a leggyakoribb a fajdalom es az izerzes zavara. Cel: A papilla vallataban levő kulonboző neuropeptidtartalmu idegrostok valtozasainak vizsgalata diabeteses patkanyokban. Modszerek: A szerzők streptozotocinnal indukalt diabeteses patkanyokban immunhisztokemiai modszerrel vizsgaltak a papilla vallataban levő neuropeptidtartalmu idegrostok mennyisegi valtozasat. Eredmenyek: A substance P, galanin, neuropeptid-Y es vasoactiv intestinalis polipeptid tartalmu idegrostok mennyisege szignifikansan megemelkedett (p<0,05) ket hettel a kezeles utan a nyelv nyalkahartyajaban. A lymphocytak es hizosejtek szama szinten szignifikansan megemelkedett. Az immunreaktiv idegrostok főleg a ham alatt, a tunica propriaban helyezkedtek el, de nehany rost behatolt a hamba is, es megfigyelhetők voltak intergemmalisan es intragemmalisan. A receptorsejtek nem mutattak immunjelzest az altaluk vizsgalt neuropeptidekre. Neuropeptid-Y es ...INTRODUCTION Abnormal sensations such as pain and impairment of taste are symptoms of approximately 10% of patients having diabetes mellitus. AIM The aim of the study was to investigate and quantify the different neuropeptide containing nerve fibres in the vallate papilla of the diabetic rat. METHODS Immunohistochemical methods were used to study the changes of the number of different neuropeptide containing nerve terminals located in the vallate papillae in diabetic rats. Diabetes was induced in the rats with streptozotocin. RESULTS Two weeks after streptozotocin treatment the number of the substance P, galanin, vasoactive intestinal polypeptide and neuropeptide Y immunoreactive nerve terminals was significantly increased (p<0.05) in the tunica mucosa of the tongue. The number of the lymphocytes and mast cells was also increased significantly. Some of the immunoreactive nerve terminals were located in the lingual epithelium both intragemmally and extragemmally and were seen to comprise dense bundles in the lamina propria just beneath the epithelium. No taste cells were immunoreactive for any of the investigated peptides. Vasoactive intestinal polypeptide and neuropeptide Y immunoreactive nerve fibres were not detected in the taste buds. For weeks after streptozotocin administration the number of the substance P, calcitonin gene related peptide and galanin immunoreactive nerve terminals was decreased both intragemmally and intergemmally. In case of immediate insulin treatment, the number of the immunoreactive nerve terminals was similar to that of the controls, however, insulin treatment given 1 week later to diabetic rats produced a decreased number of nerve fibers. Morphometry revealed no significant difference in papilla size between the control and diabetic groups, but there were fewer taste buds (per papilla). CONCLUSIONS Increased number of immunoreactive nerve terminals and mast cells 2 weeks after the development of diabetes was the consequence of neurogenic inflammation which might cause vasoconstriction and lesions of the oral mucosa. Taste impairment, which developed 4 weeks after streptozotocin treatment could be caused by neuropathic defects and degeneration or morphological changes in the taste buds and nerve fibres.

Innervation of papilla vallata in diabetic rats

Bevezetes: A diabetes mellitusban szenvedő betegek 10%-a koros erzesről panaszkodik, amelyek kozott a leggyakoribb a fajdalom es az izerzes zavara. Cel: A papilla vallataban levő kulonboző neuropeptidtartalmu idegrostok valtozasainak vizsgalata diabeteses patkanyokban. Modszerek: A szerzők streptozotocinnal indukalt diabeteses patkanyokban immunhisztokemiai modszerrel vizsgaltak a papilla vallataban levő neuropeptidtartalmu idegrostok mennyisegi valtozasat. Eredmenyek: A substance P, galanin, neuropeptid-Y es vasoactiv intestinalis polipeptid tartalmu idegrostok mennyisege szignifikansan megemelkedett (p<0,05) ket hettel a kezeles utan a nyelv nyalkahartyajaban. A lymphocytak es hizosejtek szama szinten szignifikansan megemelkedett. Az immunreaktiv idegrostok főleg a ham alatt, a tunica propriaban helyezkedtek el, de nehany rost behatolt a hamba is, es megfigyelhetők voltak intergemmalisan es intragemmalisan. A receptorsejtek nem mutattak immunjelzest az altaluk vizsgalt neuropeptidekre. Neuropeptid-Y es ...INTRODUCTION Abnormal sensations such as pain and impairment of taste are symptoms of approximately 10% of patients having diabetes mellitus. AIM The aim of the study was to investigate and quantify the different neuropeptide containing nerve fibres in the vallate papilla of the diabetic rat. METHODS Immunohistochemical methods were used to study the changes of the number of different neuropeptide containing nerve terminals located in the vallate papillae in diabetic rats. Diabetes was induced in the rats with streptozotocin. RESULTS Two weeks after streptozotocin treatment the number of the substance P, galanin, vasoactive intestinal polypeptide and neuropeptide Y immunoreactive nerve terminals was significantly increased (p<0.05) in the tunica mucosa of the tongue. The number of the lymphocytes and mast cells was also increased significantly. Some of the immunoreactive nerve terminals were located in the lingual epithelium both intragemmally and extragemmally and were seen to comprise dense bundles in the lamina propria just beneath the epithelium. No taste cells were immunoreactive for any of the investigated peptides. Vasoactive intestinal polypeptide and neuropeptide Y immunoreactive nerve fibres were not detected in the taste buds. For weeks after streptozotocin administration the number of the substance P, calcitonin gene related peptide and galanin immunoreactive nerve terminals was decreased both intragemmally and intergemmally. In case of immediate insulin treatment, the number of the immunoreactive nerve terminals was similar to that of the controls, however, insulin treatment given 1 week later to diabetic rats produced a decreased number of nerve fibers. Morphometry revealed no significant difference in papilla size between the control and diabetic groups, but there were fewer taste buds (per papilla). CONCLUSIONS Increased number of immunoreactive nerve terminals and mast cells 2 weeks after the development of diabetes was the consequence of neurogenic inflammation which might cause vasoconstriction and lesions of the oral mucosa. Taste impairment, which developed 4 weeks after streptozotocin treatment could be caused by neuropathic defects and degeneration or morphological changes in the taste buds and nerve fibres.