Biomedical subjects

Tivadar Zelles

Publications and source records attributed to Tivadar Zelles.

5 recordsLinked to original sources

PubMed2006

Changes of the different neuropeptide-containing nerve fibers and immunocells in the diabetic rat's alimentary tract.

Peripheral neuropathy is a common complication of diabetes mellitus, where neuropeptides and immunocells might play important roles in the pathogenesis of the disease. In this article we have quantified the different neuropeptide-containing nerve fibers and immunocells in the streptozotocin-induced diabetic rat's alimentary tract (tongue, duodenum, colon) using immunohistochemical and immunocytochemical methods. The immunoreactive (IR) nerve fibers were found in all layers of the alimentary tract and their distribution pattern was similar in both control and diabetic groups. Mast cell-nerve fiber contacts were rarely found in the controls. However, after 4 weeks duration of diabetes the number of IR nerve fibers and the immunocompetent cells increased significantly (P < 0.05), and the number of mast cell-nerve fiber contacts was even more significantly increased (P < 0.001). The distance between nerve fibers and immunocells was about 1 mum or even less. Some of the mast cells were degranulated in the vicinity of nerve fibers. No immunocompetent cells were IR for any antisera in the control. However, after the streptozotocin treatment, a large number of the immunocompetent cells showed immunoreactivity for SP and NPY. Counting all immunocompetent cells in whole sections showed that 12.3% of them were IR for SP and 25.4% were IR for NPY. Increased number of SP-containing nerve fibers and immunocells in diabetes mellitus might be the reason for painful neuropathy and might amplify the inflammatory reaction in an axon reflex manner; the released histamine and leukotrienes, cytokines, and chemokines might cause inflammations and lesions of the mucosa.

Animals↗

PubMed2005

Endotoxin can decrease isolated rat parotid acinar cell amylase secretion in a nitric oxide-independent manner.

Salivary mucus and amylase have an anti-bacterial nature. Bacterial endotoxin is considered to decrease mucus secreting cell activity by nitric oxide-dependent mechanisms. In this study, the actions of endotoxin on amylase secreting cell activity have been studied. Endotoxin (Escherichia coli lipopolysaccharide; 3 mg/kg, i.v., 5 h) evoked nitric oxide synthase 2 (NOS2) induction in the rat whole parotid tissue (assessed by Western blot and the citrulline assay) and in rat isolated parotid acinar cells (assessed by Western blot and immunohistochemistry), and reduced basal and acetylcholine-stimulated amylase secretion from these isolated cells. However, N(G)-nitro-L-arginine methyl ester (0.1 mg/ml, 4 days in drinking water, yielding a dose of 25 mg/kg/day) did not affect amylase release under basal or acetylcholine-stimulated conditions, either in control acinar cells or those from endotoxin challenged rats. Thus, basal, acetylcholine-evoked or endotoxin-decreased cellular amylase secretion from rat isolated parotid acinar cells does not appear to be modulated by endogenous nitric oxide.

Acetylcholine↗

PubMed2005

Morphological evidence of sensory neurons in the root of the rat tongue.

In our previous studies, a large number of substance P (SP)-immunoreactive (IR) nerve fibers were detected in the rat tongue and their number increased after inflammation, suggesting that these fibers might be involved in the axon reflex. Therefore, in this study, we have examined the different neuropeptide-containing nerve elements by light, electron, and confocal laser microscopy. SP, vasoactive intestinal polypeptide (VIP), and neuropeptide Y (NPY) IR varicose fibers were numerous compared with other ones. Small groups of ganglia with perikarya IR for SP, VIP, NPY, galanin, and somatostatin were observed. The SP-IR nerve cell bodies were mainly located in the tunica propria just below the epithelial lining. Double-labeling immunohistochemistry showed that the intrinsic SP-IR neurons did not colocalize VIP. The SP containing nerve terminals were observed in and below the epithelium as well as in very close contact to or making real synapses with other neurons in the intralingual ganglion. Our data confirmed the possibility of intrinsic sensory neurons, which might be the afferent branch of the intralingual reflex arch, while the VIP- and NPY-IR neurons located in the salivary glands, around the blood vessels, and in the muscle layer might constitute the efferent site of this reflex.

Animals↗

PubMed2004

Plasticity of the different neuropeptide-containing nerve fibres in the tongue of the diabetic rat.

Common oral complications of diabetes mellitus are xerostomia, impairment of taste, atrophic lesions of the tongue, leukoplakia, lichen oris planus, and tumours, which might be the consequence of chronic inflammation and changes in innervation. In this work, we examined the density of different neuropeptide-containing nerve fibres immunohisto- and immunocytochemically in the root of the control and diabetic rat's tongue. Quantitative analysis showed that the number of immunoreactive (IR) nerve fibres was decreased after 1 week of the streptozotocin treatment, which was prevented by immediate insulin treatment. However, after 4 weeks duration of diabetes, the number of all investigated IR nerve fibres increased significantly (p<0.05), which was further enhanced by the delayed insulin treatment. The numbers of substance P (SP) and vasoactive intestinal polypeptide IR perikarya were also increased by insulin treatment. The electron-microscopic investigations showed that some of the nerve terminals from diabetic animals were found in degeneration. After 4 weeks duration of diabetes, the number of inflammatory cells as well as the mast cell/nerve fibre contacts was also increased. The immunocells also showed IR for SP and neuropeptide Y in the diabetic rats. The insulin treatment decreased both the number and the immunoreactivity of these cells. The increased synthesis and/or regeneration of neuropeptide-containing nerves might indicate the plasticity of nerve fibres in diabetes mellitus, which might happen as a consequence of the changes in the level of neurotrophic factors released by increased number of inflammatory cells or as an effect of insulin.

Animals↗

PubMed2002

[Changes of the nerve fibers innervating the minor salivary glands in Sjögren syndrome].

INTRODUCTION: A large number of nerve fibres containing different neuropeptides/transmitters are also found in the salivary glands. The number and the distribution of nerve fibres is altered in many diseases, including in Sjögren's syndrome. AIM: Therefore in the present study the distribution and precise localisation of the nerve fibres containing the frequently observed neuropeptides were studied in the minor salivary glands. METHODS: Vasoactive intestinal polypeptide, neuropeptide Y, substance P, calcitonin gene-related peptide, somatostatin, nitric oxide synthase and tyrosine beta-hydroxylase antibodies were used as primary antisera, and then by the aid of avidin-biotin-peroxidase complex method the immunoreactive fibers in human labial glands (control and with Sjögren's syndrome) and in minor glands of the root of the rat's tongue were detected. RESULTS: Large number of vasoactive intestinal polypeptide and nitric oxide synthase immunoreactive nerve fibres were seen around the acini. The neuropeptide Y and tyrosine beta-hydroxylase positive nerve fibres were mainly found around the blood vessels. Some of the IR fibers were also found around the excretory ducts. In the biopsy of patients with Sjögren's syndrome, the acini were destroyed and only few excretory ducts were seen. The number of the nerve fibres was significantly decreased and many degenerated fibres were also observed among the acini. The electron-microscopic examinations showed that the immunoreactive nerve fibres were in close association to the secretory cells, to the smooth muscle cells of blood vessels and to the immunocells. The synaptic gap between the nerve fibres and the target cells were 40-200 nm. CONCLUSIONS: On the bases of the distribution of the different transmitters containing nerve fibres and their relationship to effector cells, the authors suppose that these transmitters control the function of the gland and regulate the blood flow. The close association to immunocells and decreasing the nerve fibres in Sjögren's syndrome imply that they may have also a role in the neuroimmunologic processes.

Adult↗