Immunohistochemical and electron-microscopical identification of neuroendocrine cells in the respiratory tract of rats with experimental uraemia

The aim of the present study was to characterise immunohistochemically and ultrastructurally the neuroendocrine cells in the pulmonary systems of uraemic rats. Pieces of lung and trachea were collected 1, 2 and 4 weeks after nephrectomy. Paraffin-embedded sections were stained with H+E and by silver impregnation. For the identification of neuroendocrine cells immunohistochemical reactions were performed with the use of specific antibodies against calcitonin (CT), somatostatin (SOM), synaptophysin (SYN), neuron-specific enolase (NSE) and calcitonin gene-related peptide (CGRP). For electron microscopy, ultrathin sections were used. The analysis showed an increased number of both the solitary neuroendocrine cells and of neuroepithelial bodies in uraemic rats when compared to control animals

Dynamics of calcitonin gene-related peptide-like cells changes in the lungs of two-kidney, one-clip rats

Taking into consideration renal hypertension-induced homeostatic disorders and the key role of calcitonin gene-related peptide (CGRP) in many, systemic functions regulating systems, a question arises as to what an extent arterial hypertension affects the morphology and dynamics of pulmonary CGRP-immunopositive cell changes. The aim of the present study was to examine the distribution, morphology and dynamics of changes of CGRP-containing cells in the lungs of rats in the two-kidney, one-clip (2K1C) renovascular hypertension model. The studies were carried out on the lungs of rats after 3, 14, 28, 42, and 91 days long period from the renal artery clipping procedure. In order to identify neuroendocrine cells, immunohistochemical reaction was performed with the use of a specific antibody against CGRP. It was revealed that renovascular hypertension caused changes in the neuroendocrine, CGRP-containing cells in the lungs of rats. The changes, observed in the neuroendocrine cells, depended on time periods from experimentally induced hypertension. The highest intensity of changes in the neuroendocrine cells was observed in the lungs of rats after 14 days from the surgery

Immunohistochemical identification and localisation of gastrin and somatostatin in endocrine cells of human pyloric gastric mucosa

The detailed description of the distribution of endocrine cells G and D producing important hormones that regulate activation of other cells in the human stomach may be a valuable source of information for opinions about mucosa changes in different diseases of the alimentary tract. The density and distribution of immunoreactive G and D cells in the pylorus of humans (donors of organs) were evaluated. The pylorus samples were collected after other organs were harvested for transplantation. The number of G cells in the pyloric mucosa of healthy people was higher than the number of D cells. G and D cells were distributed between columnar cells of epithelium mucosa. Multiform endocrine cells generally occurred: gastrin in the middle third of the mucosa and somatostatin cells in the basal half of the pyloric mucosa. The investigation of the pyloric part of the healthy human stomach showed a characteristic distribution of cells that reacted with antisera against gastrin and somatostatin

Altered cannabinoid receptor expression in pancreatic islets in experimental model of uraemia

Background: Uraemia leads to a number of metabolic and hormonal disorders including defective carbohydrate metabolism. Endocannabinoids exert their effect on insulin and glucagon secretion via activation of specific receptors named CB1 and CB2. For this reason and the absence of reports on location and immunoreactivity of CB1, CB2 receptors compared to immunoreactivity of insulin- and glucagon-secreting cells in experimental uraemia, the author decided to investigate this issue. The aim of the present study was the immunohistochemical localisation and evaluation of cannabinoid receptors (CB1, CB2), insulin and glucagon in the pancreatic islets of uraemic rats. Materials and methods: Fragments of the rat’s pancreas were collected 28 days after surgical resection of one kidney and removal of 70% of the other kidney cortex. Paraffin-embedded sections were stained with haematoxylin-eosin and immunohistochemical reactions were performed with the use of a specific antibody against CB1-, CB2-receptors, insulin and glucagon. Results: It was revealed the decreased immunoreactivity of the CB1 receptor and higher intensity of the immunohistochemical reaction against CB2 receptor as compared to the value in the control animals. Significantly higher immunoreactivity of glucagon-positive cells and weaker immunoreactivity of insulin-positive cells were observed in pancreatic islets of uraemic rats. Conclusions: The obtained results indicate the involvement of cannabinoid receptors in the pathomechanism of carbohydrate metabolism disorders, associated with abnormal secretion of hormones by the α and β cells in uraemia

Gastrointestinal neuroendocrine cells in various types of hypertension – a review

Recent years have witnessed a progressive increase in the number of people suffering from hypertension, which is one of the most serious health problems in the world. Hypertension results in changes leading to function disorders, not only of the organs and tissues, but also changes leading to the activation of many defense mechanisms in the cells in order to prevent damage. One of them is the expression of neuroendocrine (NE) hormones and biologically active substances, which has been the focus of extensive research for a number of years. Active involvement of NE cells and the biological and therapeutic properties of various substances synthesized by them have been confirmed in clinical trials and in various experimental models. Results obtained in many research studies indicate intense activity of enteroendocrine cells in the gastrointestinal tract in various pathological conditions, including hypertension. In the present review, we discuss the morphological and functional changes of gastrointestinal neuroendocrine cells under conditions of different types of hypertension

Quantitative evaluation of CART-containing cells in urinary bladder of rats with renovascular hypertension

Recent biological advances make it possible to discover new peptides associated with hypertension. The cocaine- and amphetamine-regulated transcript (CART) is a known factor in appetite and feeding behaviour. Various lines of evidence suggest that this peptide participates not only in control of feeding behaviour but also in the regulation of the cardiovascular and sympathetic systems and blood pressure. The role of CART in blood pressure regulation led us to undertake a study aimed at analysing quantitative changes in CART-containing cells in urinary bladders (UB) of rats with renovascular hypertension. We used the Goldblatt model of arterial hypertension (two-kidney, one clip) to evaluate quantitative changes. This model provides researchers with a commonly used tool to analyse the renin-angiotensin system of blood pressure control and, eventually, to develop drugs for the treatment of chronic hypertension. The study was performed on sections of urinary bladders of rats after 3-, 14-, 28-, 42 and 91 days from hypertension induction. Immunohistochemical identification of CART cells was performed on paraffin for the UBs of all the study animals. CART was detected in the endocrine cells, especially numerous in the submucosa and muscularis layers, with a few found in the transitional epithelium and only occasionally in serosa. Hypertension significantly increased the number of CART-positive cells in the rat UBs. After 3 and 42 days following the procedure, statistically significantly higher numbers of CART-positive cells were identified in comparison with the control animals. The differences between the hypertensive rats and the control animals concerned not only the number density of CART-immunoreactive cells but also their localization. After a 6-week period, each of the rats subjected to the renal artery clipping procedure developed stable hypertension. CART appeared in numerous transitional epithelium cells. As this study provides novel findings, the question appears about the type of connection between hypertension and the functioning and activity of CART in the urinary tract (UT). The study gives rise to the assumption that high blood pressure can be a factor that intensifies CART secretion. In conclusion, the endocrine system of the urinary tract is modified by renovascular hypertension. This may affect the production of hormones and biologically active substances and contribute to the development of possible hypertension complications. In order to fully comprehend the role of the CART peptide in blood pressure regulation, further analyses are necessary

Evaluation of CART-, glucagon-, and insulinimmunoreactive cells in the pancreas of an experimental rat model of unilateral renal artery stenosis

Hypertension is one of the most frequently occurring diseases worldwide. Approximately 10% of the population with hypertension reveal the secondary type of hypertension. The aim of this study was to evaluate the cells containing CART, insulin and glucagon in the pancreas of rats with renovascular hypertension. An experimental model of hypertension in rats according to Goldblatt (2K1C model of hypertension) was used in the study. The experimental material (pancreas) was collected in the 6th week of the study. Cells containing CART, insulin and glucagon were evaluated using immunohistochemical and morphometric methods. Pancreatic islet cells were evaluated based on the number and intensity of staining. The investigation showed an increase in the number and immunoreactivity of CART containing cells, 6 weeks after partial unilateral ligation of the renal artery. There was a significant decrease in the number of glucagon-IR cells. Although intensity of staining these cells did not change. No differences were observed in the number and staining affinity of insulin-containing cells. On the basis of the study it can be stated that the endocrine system of pancreas undergoes changes in the course of renovascular hypertension. This may affect the production of hormones and contribute to the development of possible hypertension complications

Gastrointestinal neuroendocrine cells in various types of hypertension – a review

Recent years have witnessed a progressive increase in the number of people suffering from hypertension, which is one of the most serious health problems in the world. Hypertension results in changes leading to function disorders, not only of the organs and tissues, but also changes leading to the activation of many defense mechanisms in the cells in order to prevent damage. One of them is the expression of neuroendocrine (NE) hormones and biologically active substances, which has been the focus of extensive research for a number of years. Active involvement of NE cells and the biological and therapeutic properties of various substances synthesized by them have been confirmed in clinical trials and in various experimental models. Results obtained in many research studies indicate intense activity of enteroendocrine cells in the gastrointestinal tract in various pathological conditions, including hypertension. In the present review, we discuss the morphological and functional changes of gastrointestinal neuroendocrine cells under conditions of different types of hypertension