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.

Histological and histochemical study of the magnocellular neuroendocrine system in white rat after parenteral administration of adrenaline.

The effect of a single dose of adrenaline on the neurosecretory action of the hypothalamo-hypophyseal system was investigated in 90 male rats. Increased release and transport of neurosecretory material were observed after a low dose of adrenaline, and the enhancement of the neurosecretory process was noted following a high dose. As shown in numerous reports, there is a link between the neuroendocrine system and the hypothalamic adrenergic system.

Experimental model of hepatic venoocclusive disease (VOD) caused by dactinomycin--preliminary report about hepatoprotective effect of amifostine.

UNLABELLED: The purpose of the study was elaboration of the experimental model of hepatic venoocclusive disease (VOD) induced by dactinomycin and investigation of possible hepatoprotective effects of amifostine and heparin individually or in combination with dexamethasone. 198 Wistar strain male rats were used in the trial in two series of experiments. In the first series the experimental model of VOD induced by dactinomycin was elaborated on the group of 18 animals (divided into 3 groups receiving intraperitoneally isotonic salt solution, dactinomycin or nitrosamine). Nitrosamine--a well-known agent causing VOD--was used as positive control. Open biopsies of the liver and blood collections were repeated in order to determine liver enzymes' concentrations. Histopathological examinations demonstrated that dactinomycin caused liver lesion corresponding with VOD picture. Second series of animals was divided into 6 groups receiving the following drugs: I--0.9% NaCl solution, II--dactinomycin (ACT), III--ACT + fraxiparine s.c., IV--ACT + fraxiparine + dexamethasone, V--ACT + amifostine. Five animals from each group were sacrificed on the 3rd and 7th day after each cycle of drug administration. Blood was drawn in order to determine the following: AspAT, AlAT, Falk, GGTP and LDH. Intravital wedge biopsies under anesthesia with the use of inactin were also performed. Liver samples were stained with the use of H&E, p. a. S and Gomory's techniques. We did not find significant differences in liver enzymes' levels between the groups. Pathological changes corresponding with VOD picture of different intensification were found in liver samples from all the rats receiving ACT. Changes became more and more intensive after consecutive cycles. Lesion of central veins' and liver sinusoids' endothelium dominated. Fraxiparine administered individually or in combination with dexamethasone did not prevent the lesion. Administration of amifostine before ACT decreased pathomorphological changes in liver. Dactinomycin caused homogenous subclinical liver lesion corresponding with VOD. It may also occur in children receiving ACT in the course of nephroblastoma's treatment. But probably the changes are too subtle to manifest themselves clinically with exception of patients particularly sensitive (for example after previous radiotherapy). Lack of differences observed in liver enzymes' levels between the groups supports the explanation. Markers of lesion of liver vessels' endothelium should be looked for to make more specific diagnostics of VOD possible. Hepatoprotective properties of amifostine need further studies. CONCLUSIONS: 1. It is possible to create the experimental model of VOD induced by dactinomycin administration. 2. Amifostine seems to act hepatoprotectively to liver lesions caused by dactinomycin.

Hypothalamo-neurohypophysial magnocellular neuroendocrine system of field voles after acute heat or cold stress.

Hypothalamo-neurohypophysial magnocellular neuroendocrine system (H-NH MC NES) of field voles was described in normal conditions and after acute heat or cold stress. 60 mature males of field voles were used for examinations after 2 weeks of adaptation to stable conditions of laboratory keeping. 10 animals were the controls. Another group of 25 field voles were subjected to sudden cold of -15 degrees C for 3 hours. The third group of 25 field voles were subjected to sudden heat of +32 degrees C for 3 hours. Neurosecretory material in paraffin 6 microns sections was stained with paraaldehyde fuchsin (fixed in Bouine fluid in the modyfication of Bock et al. 1968) and tigroid was stained with toluidine blue (fixed in Carnoy fluid). Routine staining with hematoxylin and eosin was used for comparison. It was found that H-NH MC NES in field voles has similar body structure as that described in many reports for laboratory H-NH MC NES of rodents. Supraoptic nucleus (SON) consisted of large multipolar neurocytes and paraventricular nucleus (PVN) consisted of slightly smaller neurocytes. PVN also included areas with small neurocytes. Acute heat or cold stress evoked enhanced concentration of neurosecret in SON and PVN and in the remaining H-NH MC NES structures of field voles simultaneously a decrease of tigroid contents was observed in neurocytes of SON and PVN after heat stress.

The effect of X-radiation on the hypothalamo-hypophyseal neurosecretory system of the rat.

The aim of the study was to reveal alterations in the macrocellular neurosecretory system of the rat which occur under the influence of X-radiation. The experiment was carried out on 15 male Wistar rats, divided into 1 control and 4 experimental groups. The animals were subjected to total-body-X-irradiation in a dose of 300R. Brains and cerebral pituitaries were collected after decapitation and fixed in Bouine's fluid. Staining with haematoxylin & eosin and paraldehyde fuchsin was applied. A reduction in the neurosecrete content was found after 7 days following irradiation both in the area of perikarya and nerve processes of SON and PVN. In animals dissected on the 14th and 21st day following irradiation, a shift of neurosecrete along the neurosecretory path was observed (via nerve processes to the posterior lobe of cerebral pituitary). On the 28th day, the morphological picture of the system examined was similar to the control one. The above results indicate that initially X-radiation causes a decrease in the production of neurosecrete within SON and PVN; later, however, the amount of neurosecrete is increased, like in control nuclei.