Modulation of hematopoiesis by ketanserin in erythropoietin-treated uremic patients: evidence from platelet studies.

Recombinant human erythropoietin (EPO) not only ameliorates the anemia of renal failure but also modulates platelet function and corrects uremic platelet serotonin (5-hydroxytryptamine, 5-HT) storage pool deficiency. We studied if ketanserin, a blocker of platelet and vascular smooth muscle receptors for 5-HT, could reverse any EPO-induced changes in hemostasis. A complete blood count, immunoreactive serum EPO concentration, skin bleeding time (BT) and whole blood platelet aggregation (electric impedance method) induced by ristocetin and ADP, and intraplatelet and whole blood 5-HT, were determined in seven chronic hemodialysis (HD) patients before and after 1, 2, 4 and 8 weeks of EPO therapy, and repeated after a 4-week co-treatment with oral ketanserin.

Effects of combination of cyclosporine with losartan or enalapril on kidney function in uremic rats.

Long-term treatment with cyclosporine in solid organ transplantation has been shown to be associated with the development of hypertension and nephrotoxicity. Angiotensin-converting enzyme inhibitors have well-known nephroprotective properties and may prevent cyclosporine A (CYA)-induced hypertension. Angiotensin receptor 1 antagonists have similar properties.

Thyroid C cells in male and female rats with chronic renal failure.

The kidneys are responsible for iodine and of thyroid hormone biodegradation. The aim of this study was the histomorphological and immunohistochemical evaluation of the influence of sex on parafollicular thyroid C cells in rats with chronic renal failure. The experiment included 40 Wistar rats after subtotal nephrectomy, after sham operation, and without any surgical procedure.

Preliminary evaluation of pancreatic islets in rats with experimental uremia and after thyroparathyroidectomy.

Hormonal disorders are the permanent symptoms of renal failure. They concern all known hormones and can be due to quantitative changes of the secretory activity and disturbances of endocrine cell functions. The aim of this study was to establish whether experimental thyroparathyroidectomy in uremic animals causes detectable histomorphological changes in endocrine cells of pancreatic islets.

The dynamics of morphological changes in the pyloric endocrine cells of rats with uremia.

Disturbances in renal homeostatic function lead to changes in endocrine cell secretory activity. The aim of this study was the histomorphological estimation of dependence of gastric APUD system cell morphology and function on the time after subtotal nephrectomy in Wistar rats. Fragments of gastric pylorus were collected 1.

Gastric endocrine cells in rats with uremia and after thyroparathyroidectomy.

The decrease in active kidney parenchyma amount causes disorders in hormone secretion processes and their inactivation failure. Experimental thyroparathyroidectomy is connected with an abrupt reduction in endocrine cells and hormones produced by them, which can be a stimulating factor as far as the increase and intensity of endocrine gastric cells activity is concerned. The aim of the study was the histomorphological and immunohistochemical evaluation of these cells in the gastric pylorus.

Immunoreactivity of neuroendocrine cells in the respiratory tract in rats with experimental uremia after thyroparathyroidectomy.

Animals with experimental uremia, which underwent thyroparathyroidectomy, reveal numerous metabolic disorders that can influence morphology and activity of endocrine cells of the scattered neuroendocrine system. The aim of the study was the evaluation of the influence of thyroparathyroidectomy in rats with chronic renal failure on APUD system cells localized in the respiratory tract. The examination was conducted on the group of 20 rats.

Preliminary evaluation of gastric endocrine cells in rats with experimental uremia.

Chronic renal failure can be the cause of various disturbances in hormonal and electrolyte metabolism, including calcium and phosphate metabolism. The aim of this study was the evaluation of pyloric endocrine cells in Wistar rats with experimental uremia. Fragments of gastric pylorus were collected 30 days after nephrectomy.

Preliminary evaluation of neuroendocrine cells in the respiratory tract in rats with experimental uremia.

The goal of this study was to investigate the influence of experimetally induced chronic renal failure on endocrine cells in the respiratory tract in rats. After 30 days of uremia, the fragments of rat lungs were collected. Paraffin sections were stained using H+E, silver impregnation and immunohistochemistry with specific antibodies against calcitonin (CT), synaptophysin (SY), somatostatin (ST), and neuron-specific enolase (NSE).

Preliminary evaluation of thyroid C cells in rats with chronic renal failure.

Numerous water-electrolyte and hormonal disturbances, including secondary hyperparathyroidism, occur in the course of chronic renal failure. It is assumed that chronic renal failure should affect the activity of C cells in the thyroid gland. Thus, the aim of the study was to evaluate immunohistochemically thyroid C cells in rats with experimental uremia.

Preliminary evaluation of endocrine cells in the rat respiratory tract after thyroid and parathyroid gland removal.

The complete thyroid and parathyroid gland removal leads to the abrupt reduction of calcitonin, which can be a factor stimulating growth and intensified activity of APUD system cells in the respiratory tract. Thus, neuroendocrine cells in the lungs and trachea in rats after thyroid and parathyroid removal were evaluated. Paraffin specimens of the examined organs were stained with H+E and impregnated with silver.

Preliminary immunohistochemical investigations of human thyroid C cells in the simple and hyperactive nodular goitre.

The aim of this study was to carry out histomorphological and immunohistochemical analysis of thyroid C cells in 30 patients with simple goitre and hyperactive goitre including Graves-Basedow (G-B) disease, treated surgically. Four tissue samples were always taken from the same internal parts of the gland where the number of C cells in physiological conditions was the highest. C cells were detected in paraffin sections after impregnation with silver salt (Grimelius method) or immunohistochemically, with antibodies against calcitonin, synaptophysin, chromogranin A and neuron-specific enolase.

Preliminary evaluation of influence of gemcitabine (Gemzar) on proliferation and neuroendocrine activity of human TT cell line: immunocytochemical investigations.

The choice treatment of medullary thyroid carcinoma (MTC) is total thyroidectomy. It is difficult to evaluate effectiveness of chemotherapy due to the rare incidence of MTC. Gemcitabine is a new drug of antimetabolite nucleoside group used in treatment of cancers since 1996.

Platelet serotonergic mechanisms in patients with cancer of the urinary bladder.

Platelet reactivity of hypertensive patients and patients with cancer of the urinary bladder was examined in vitro in comparison with normotensive patients. A significant increase in free serotonin in the plasma of patients with cancer of the bladder and a less pronounced increase in hypertensive subjects was observed. The platelets in neoplastic disease and hypertension showed a significant reduction in the kinetics of serotonin uptake.

[Erythropoietin and hypertension].

Hypertension is one of the adverse effects associated with recombinant human erythropoietin (rHuEPO) therapy for anaemia in hemodialysed patients. The incidence of hypertension is reported to be 10-15%. The exact mechanism of rHuEPO-induced hypertension has not been fully elucidated, although in this paper several theories have been presented.

Long-term effects of erythropoietin on platelet serotonin storage and platelet aggregation in hemodialysis patients with reference to ketanserin treatment.

Correction of uremic platelet serotonin (5-HT) storage pool deficiency is one of the very early hemostatic effects of erythropoietin (Epo) therapy. In this work, platelet 5-HT with relation to primary hemostasis was studied in 15 hemodialysis patients treated with Epo for 8 months. Moreover, effects of ketanserin, a blocker of platelet and vascular smooth muscle cell 5-HT2A receptors, in these patients were followed.

Nitric oxide and prostacyclin are involved in antithrombotic action of captopril in venous thrombosis in rats.

The long-term administration of captopril to patients with a left ventricular dysfunction after myocardial infarction reduces the rate of recurrent coronary thrombosis. Thus, in the present study we investigated the influence of angiotensin-converting enzyme inhibitors (ACE-Is) on experimental venous thrombosis in normotensive rats and the involvement of NO and PGI2 in this effect. Animals were treated with captopril (1.

The effect of tacrolimus (FK506) and cyclosporin A (CyA) on peripheral serotonergic mechanisms in uremic rats.

The aim of this study was to investigate the mechanism of hypertension and thromboembolic events induced by cyclosporin (CyA) and tacrolimus (FK506) in respect to their action on the serotonergic blood system. The study was carried out on healthy rats and those with experimental chronic renal failure. CyA injected into healthy and uremic rats caused an increase in serotonin (5-HT) concentration levels in whole blood and platelets.

Cyclosporine A affects serotonergic mechanisms in uremic rats.

The aim of this study was to investigate the mechanism of cyclosporine-induced hypertension in respect to its action on blood serotonergic system. The experiment was carried out on healthy rats and animals with experimental chronic renal failure. Cyclosporine A (CsA) injected into the healthy and uremic rats caused an increase in systolic blood pressure.

Effect of endothelin-1 on some hemostatic parameters in normotensive rats.

Some parameters of hemostasis and fibrinolysis were investigated in rats administered with endothelin-1 (ET-1). ET-1 (0.5, 1.