[Experimental hepatic regeneration after ligation of the hepatic artery and after peri-arterial sympathectomy].
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
C Cavallotti
Publications and source records attributed to C Cavallotti.
[Experimental hepatic regeneration in the rat previously subjected to partial ligature of the portal vein, latero-lateral anastomosis and termino-lateral portacaval anastomosis].
Explore the source record for details and available documents.
Animals↗
(3H)-spiroperidol binding sites in the rabbit splenic artery.
The topographic distribution of (3H)-spiroperidol binding sites (corresponding to dopamine receptors likely) was studied in rabbit splenic artery by the use of a histoautoradiographic technique. (3H)-spiroperidol was localized preferentially at the level of smooth muscle cells of the media as well as in close relation with cellular membrane of endothelial cells. The findings of a constant distribution of (3H)-spiroperidol binding sites within the medial layer of the splenic artery led us to hypothesize that these receptors mediate the relaxation of the splenic artery determined by dopamine infusion.
Animals↗
Changes of dopamine-sensitive cyclic AMP-generating system in the rat hippocampus as a function of age.
The dopamine (DA) D(1) and D(2) receptors coupled to the 3',5'-cyclic adenosine monophosphate (cAMP)-generating system were studied in membrane particles of the dorsal hippocampus in 3 (considered to be young), 12 (considered to be adult) and 24 (considered to be old) month male Sprague-Dawley rats. Activation of D(1) receptors with DA, apomorphine or SKF 82526 enhanced accumulation of cAMP in the hippocampus of rats of the three age groups examined. This stimulatory effect was significantly reduced in adult rats. No further changes were noticeable in old animals. D(2) receptors negatively coupled to cAMP generation were demonstrated by incubating hippocampus membrane particles with SCH 23390 plus DA or with D(2) receptor agonists quinpirole or bromocriptine. The D(2) inhibitory effect on cAMP generation was unchanged in the three age groups. No difference was detectable between young, adult and old rats in the activation of cAMP production by forskolin.
Journal Article↗
Age-related changes in sulfide-silver stainable fibres in the rat cerebral cortex.
The present study was designed to assess the age-dependent changes in sulfide-silver stainable fibres in frontal, parietal and occipital cortex areas of the rat cerebral cortex. Male Sprague-Dawley rats of 2 months (young), 12 months (adult) and 24 months (aged) were used. Sulfide-silver stainable fibres, which represent predominantly zinc-containing associational fibres arising from local cortical interneurons, were visualized using the neo-Timm histochemical technique. The density of sulfide-silver stainable fibres within the neuropil of laminae I-III (upper zone) and of lamina V (lower zone) of the different cerebral cortex areas was assessed microdensitometrically. In the frontal and parietal cortices the density of sulfide-silver stainable fibres was higher in adult and in aged than in young rats both in the upper and in the lower zones. No significant differences were noticeable in the density of sulfide-silver stainable fibres between adult and old rats. In the occipital cortex the density of sulfide-silver stainable fibres was similar in young or adult rats. but was remarkably increased in old animals. The possibility that the increase in the density of sulfide-silver stainable fibres represents a compensatory mechanism in the cerebral cortex area showing the most consistent nerve cell loss is discussed.
Journal Article↗
3H-muscimol binding sites within the rat choroid plexus: pharmacological characterization and autoradiographic localization.
By using combined radioreceptor binding and autoradiographic techniques, we were able to localize the GABA 'A' receptor agonist 3H-muscimol in the rat choroid plexus. Within sections of rat choroid plexus, 3H-muscimol was bound specifically with a KD of 37 nM and a Bmax of 253 pmol/mg tissue. These values are consistent with the labelling of GABA 'A' receptor sites. The autoradiographic studies demonstrated that 3H-muscimol was attached to the epithelium of the choroid plexus. The blood vessels of the plexus did not exhibit specific labelling. Examination of these data suggests the existence of GABAergic mechanisms which control cerebrospinal fluid production or flow.
Animals↗
Catecholaminergic nerve fibers in bronchus-associated lymphoid tissue: age-related changes.
Age-related changes of the catecholaminergic nerve fibers of the trachea, bronchial smooth muscle, lung capillaries and bronchus-associated lymphoid tissue (BALT) were studied in male Wistar rats aged 3 months (young), 12 months (adult) and 24 months (old/aged). Catecholamine histo- and immuno-fluorescence techniques were used, associated with image analysis and high pressure liquid chromatography with electrochemical detection of nor-epinephrine (nor-adrenaline). In young rats, blue-green fluorescent nerve fibers supply the trachea-bronchial smooth muscle and tracheal and bronchial glands. These structures are innervated by a delicate network of nerve fibers, being rich in varicosities. Pulmonary capillaries are sparsely innervated. The highest nor-epinephrine concentration was found in the trachea and bronchi, followed by BALT. The density and the pattern of noradrenergic nerve fibers of the trachea-bronchial tree or of the pulmonary vessels were similar in young and adult rats. In aged rats, a loss of noradrenergic nerve fibers, involving primarily the supply to the smooth muscle of the trachea-bronchial tree, was observed. Fluorescence microscopic techniques demonstrated a higher sensitivity than nor-epinephrine assay in detecting changes of the sympathetic nerve supply of the trachea-bronchial tree, pulmonary vessels and BALT. The possible significance of reduced noradrenergic nerve supply of the trachea-bronchial-pulmonary tree in aged rats is discussed.
Aging↗
Age-related changes in rat retina.
PURPOSE: To describe the changes in rat retina occurring with ageing by means of histological methods, scanning electron microscopic observations and morphometrical data; and to study by means of biochemical methods the amount of protein content in retinal tissues. METHODS: Samples of fresh retinal tissue obtained from young, adult, and aged rats were studied by means of traditional histological methods and by scanning electron microscopy. Particular attention was paid to morphometrical data and to the changes which occur with ageing. With the aid of a quantitative analysis of images, a large amount of morphometrical data was collected. Moreover, the amount of protein content in retinal tissues has been determined. RESULTS: Retinal thickness significantly decreases with age. The ganglion cells seem to be more vulnerable to age-related loss than other retinal cells. The number of retinal capillaries is diminished with age. The intercellular connections between photoreceptors, the number of cellular processes, and the number of synaptic bodies of the bipolar cells also decrease significantly with age. These results were all confirmed by scanning electron microscopy observations and morphometrical findings. Biochemical dosage of proteins demonstrates that retinal tissues decrease with age. CONCLUSIONS: All morphological, morphometrical, ultrastructural and biochemical data are concordant in demonstrating that the retinal tissues of rats undergo specific changes with age. Our findings are in agreement with those described by previous authors and underline that the rat retina can be considered an optimal model for studies on neuronal maturation and/or neuronal ageing. Since our data have confirmed that many changes occur in rat retina with ageing, we can hypothesize that rat retina is particularly sensitive to developmental changes and to senile decay.
Aging↗
Diabetic rats treated by low molecular weight heparin OP 2123/parnaparin: morphological changes in the kidney and heart.
AIM: Early morphological alterations in the rat kidney and heart due to experimentally induced diabetes are described in order to evaluate the possible therapeutic role of low molecular weight heparin (LMWH; OP 2123/parnaparin). METHODS: Our findings concern the alterations observed in the rat kidney and heart because these are the organs (together with the retina) mainly involved in the early morphological angiopathic modifications associated with diabetic damage of organs and tissues. In diabetic animals treated with LMWH, the Periodic Acid-Schiff (PAS) reaction showed a slight decrease when compared with the diabetic control group. Photographs were submitted to the quantitative analysis of images using a Quantimet 500 Image Analyzer (Leica) equipped with specific software. The following parameters were measured: (1) total area occupied by alkaline phosphatase (AP)-positive capillaries; (2) number and diameter of AP-positive capillaries; (3) distribution and total area occupied by PAS-positive structures (related to the intensity of the reaction resulting from the different amount of mucopolysaccharides). RESULTS: LMWH treatment is efficient in preventing these modifications, above all in the kidney. The histological study of the heart and kidney shows no significant, relevant alterations. However, the histological study of the mucopolysaccharides in diabetic animals highlighted a tendency for the heart to accumulate these substances. LMWH treatment only modestly reduced this accumulation. CONCLUSIONS: Previous evidence demonstrating a beneficial effect of therapy based on heparan sulphate proteoglycans and/or other heparin-like substances in insulin-dependent diabetes mellitus seems to be confirmed by our experimental results in different organs of adult rats. In fact, parnaparin treatment is effective (in our experience) for ameliorating the morphological pattern observed early in some diabetic tissues of rats and, above all, in the kidney.
Animals↗
Uveoscleral outflow in dog's eye: role of several enzymes.
The morphological pattern of several enzymes (succinic dehydrogenase--SDH, glucose-6-phosphate dehydrogenase--G6PDH and lactic dehydrogenase--LDH) was evaluated in normal dog eyes. Special attention was paid to the uveo-scleral tissue. Cryostatic sections of dog eye were stained with toluidine blue for the recognition of the microanatomical details or with histoenzymatic methods for SDH, G6PDH and LDH activities using sodium succinate, glucose-6-phosphate and sodium lactate as substrates respectively, nicotinamide adenine dinucleotide (NAD) as a reducing agent and sodium nitro-blue-tetrazolium as a colouring substance. A moderate positive reaction for SDH and a strong positive reaction for LDH were observed in the uveoscleral tissue, while G6PDH gave negative staining. Some considerations regarding a possible active role of these enzymatic activities to the aqueous humor outflow are suggested.
Animals↗
A morphometric study of age changes in the rat optic nerve.
Age-related changes of the optic nerve fibres were studied in 3-month-old (young), 12-month-old (adult) and 24-month-old (aged) male Sprague-Dawley rats. The optic nerve was harvested with particular care from the intracranial portion. Cross sections from the optic nerve of animals of different age groups were stained with toluidine blue and examined under a light microscope at low and high magnification. Other sections were stained for the demonstration of glial cells using the method described by Holzer. A third group of sections were stained by the immunohistochemical method to detect glial fibrillary acidic protein, which is a marker for localising and characterising astrocytes. All these morphological results were subjected to the quantitative analysis of images and to statistical analysis of the values to identify significant morphometric data. Biochemical dosages of proteins were also performed on homogenised fragments of the optic nerve. Our results demonstrate that the following age-related changes can be observed: (1) an increase in meningeal membranes, (2) an increased number of astrocytes, (3) an increase in areal density of glial fibrillary acidic protein immunoreactivities, (4) an increased thickness of the entire optic nerve and an increased area of the nerve, (5) a decreased number of nerve fibres and (6) a decrease in the nerve fibre/meningeal membrane ratio from 3:1 to 1:1. Moreover, the amount of protein does not change with age. The rat optic nerve, therefore, appears sensitive to aging processes.
Aging↗
Metabolic changes in rabbit lens induced by treatment with dexamethasone.
Metabolic changes in the rabbit lens have been studied by means of nuclear magnetic resonance spectroscopy. These changes have been induced by prolonged topical treatment with dexamethasone. Our results demonstrate an increase in sorbitol, sorbitol-3-phosphate, fructose-3-phosphate, glycerol-3-phosphate and glucose-6-phosphate levels and a decrease in glutathione sulphate (GSH) and myo-inositol levels, in agreement with what was observed in lenses from streptozocin-diabetic rats before lens opacity. The hyperglycaemia can only partially explain all these observed biochemical variations. The lack of increase in the intermediates of pentose cycle, such as sedoheptulose-7-phosphate, seems to support the hypothesis of an inhibition of glucose-6-phosphate dehydrogenase by dexamethasone treatment. Finally dexamethasone treatment induces a decrease in GSH. The decreasing or the loss of GSH has been suggested as a possible pathogenic mechanism in the cataract formation.
Administration, Topical↗
Age-related changes in catecholaminergic nerve fibers of rat heart and coronary vessels.
BACKGROUND: Age-related changes of catecholaminergic nerve fibers supplying the myocardium and the coronary vessels were studied in adult and in old rats. OBJECTIVE: The purpose of this study was to investigate whether there are quantitative changes in myocardial and/or coronary catecholaminergic nerve fibers and related neurotransmitters. METHODS: Samples of myocardium and/or coronary vessels were studied by means of glyoxylic acid induced fluorescence, aldehyde-induced fluorescence, and neuropeptide Y immunoreactivity. All morphological results were submitted to quantitative analysis of images. Biochemical dosage of proteins and of norepinephrine was also performed, and morphological data were compared with biochemical ones. Finally, all data were subjected to statistical analysis. RESULTS: Our findings are indicative of an age-related decrease of all types of fluorescent sympathetic nerve fibers in rat heart and coronary arteries. Moreover, our data show that aging induces a strong decrease of norepinephrine levels in tissue homogenates of rat heart and coronary vessels. The majority of the catecholaminergic nerve fibers that show strong age-related changes are not contiguous with contractile cells of myocardium and/or of vascular wall. In fact, these fibers are located in adventitial (or epicardial) and in endothelial (or endocardial) layers. CONCLUSION: The decrease of the catecholaminergic innervation of heart and coronary vessels of old rats can be in close relationships to the poor cardiac and/or coronary functions observed in old animals.
Aging↗
Localization of dopamine receptors in the rabbit lung vasculature.
The localization of dopamine receptor subtypes in the rabbit pulmonary circulation was investigated by using combined radioligand binding and light microscope autoradiography techniques. Dopamine D1-like receptors, probably belonging to the dopamine D1 receptor subtype, were demonstrated in sections of rabbit lung using [3H]-SCH 23390 as a ligand. This site is located within the tunica intima and the tunica media of large intrapulmonary artery branches (diameter > 300 microns) as well as within the tunica media of medium-sized pulmonary artery branches (diameter between 100 and 300 microns). No [3H]-SCH 23390 binding sites were found in small-sized pulmonary artery branches (diameter < 100 microns) or in pulmonary veins. Dopamine D2-like receptors, probably belonging to the dopamine D2 receptor subtype, were demonstrated with radioligand binding techniques in sections of extrapulmonary arteries but not of lung using [3H]-spiroperidol as a ligand. Light microscope autoradiography revealed the localization of this site within the tunica adventitia of extrapulmonary arteries as well as of large- and medium-sized intrapulmonary artery branches. The different anatomical localization of dopamine D1- and D2-like receptors in the rabbit pulmonary vasculature suggests that these sites are involved in the modulation of pulmonary vascular tone by interacting with different receptors having endothelial, muscular and probably prejunctional localization. The functional significance of the uneven distribution of dopamine receptor subtypes throughout the pulmonary vascular bed should be clarified in future studies.
Analysis of Variance↗
Anatomical variations of the ulnar and median nerves in the upper limb.
The aim of our study was the evaluation of the anatomy of ulnar and median nerves in the upper limb in order to ameliorate knowledge on the clinical anatomy of these nerves. In fact, further information on this topic may be useful owing to its possible clinical relevance when planning surgical anatomy and reconstructive surgery in tumor affected and injured patients. The relationships between ulnar and median nerve and neighbouring anatomical structures have been examined, together with the course and ramification of the ulnar and median nerves in six fresh cadavers. Moreover, we have performed a review of the literature. Four specific aspects were evaluated during dissection: 1) division modality of the ulnar nerve at the wrist; 2) anatomical details of the medial humeral epicondyle; 3) anatomical relationships between median nerve and retinaculum flexorum; 4) median-ulnar nerves anastomosis. Our results show that: the medial humeral epicondyle shows specific anatomical details in relation to the ulnar nerve; the relationships between the median nerve and the transverse carpal ligament may be characterized by one or two nerve trunks (two cases of bifid median nerve in our experience); median-ulnar nerve anastomosis may be also found at various levels. Comparing our results with those of the available literature we can conclude that anatomical variations of ulnar and median nerve in the upper limb are not an infrequent finding and their clinical, diagnostic and surgical relevance should be considered.
Aged↗
Autoradiographic localization of peripheral [3H]-hydergine binding sites.
The anatomical distribution of the ergot derivative [3H]-hydergine (co-dergocrine mesylate) was analyzed by the use of an in vitro autoradiographic technique on frozen sections of rat heart, mesenteric and renal arteries, adrenal gland and kidney. In the heart, [3H]-hydergine was bound by atria and by myocytes of ventricles. In the arterial wall, the drug was bound primarily by the adventitia, by the adventitia-media border and by the intimal layer. The density of adventitial and adventitial-medial binding sites has an inverse relation with the diameter of mesenteric or renal vessels. In the adrenal gland, [3H]-hydergine was bound primarily by the medulla and, in lesser amounts, by the zona glomerulosa. In the kidney, the drug was localized within the arterial tree as well as in cortical tubules and in medullary collecting tubules. The above findings suggest that [3H]-hydergine is bound by various structures involved in the regulation of cardiovascular homeostasis. Interaction with these sites probably accounts for the antihypertensive action of hydergine.
Adrenal Glands↗
Are muscarinic receptors present in rat pial or intracerebral vessels?
Experiments were performed to determine whether muscarinic receptors were present within rat pial or intracerebral vessels. Localization of muscarinic receptors was determined by autoradiography using [3H]-quinuclidinyl benzilate ([3H]-QNB) as a ligand on brain sections of the frontoparietal and the temporal cortex, the neostriatum and the hippocampus. [3H]-QNB was bound specifically to sections of rat brain in a manner consistent with the labelling of muscarinic receptors. A high density of muscarinic receptors was found primarily in the neostriatum, followed, in descending order, by the cerebral cortex and the hippocampus. However, no specific [3H]-QNB binding was observed at the level of either the pial or intraparenchymal vessels. On the basis of the present data, the existence of muscarinic receptors within rat pial arteries and arterioles, as well as within intracerebral vessels, seems to be highly questionable.
Animals↗
Muscarinic cholinergic receptors in the hippocampus of the aged rat: effects of long-term hydergine administration.
The effects of senescence and of long-term hydergine treatment on the density and the pattern of muscarinic cholinergic receptors in rat hippocampus were studied using combined radioreceptor binding and autoradiography with [3H]-quinuclidinyl-benzilate ([3H]-QNB) as a ligand. [3H]-QNB accumulated in the hippocampus of 3 month old rats, primarily in the stratum oriens of the CA1 and CA2 fields, followed in descending order by the molecular layer of granule cells of the dentate gyrus and the CA3 field. The density and pattern of [3H]-QNB binding sites in the hippocampus of 16 month old rats were the same. In contrast, the density of [3H]-QNB binding sites in the hippocampus of 22 months old rats was significantly reduced, mainly in the granule cells of the dentate gyrus, next in the CA3 and in the CA1-CA2 fields. Hydergine treatment (0.6 mg/kg and 1 mg/kg, p.o.), started at 16 months of age and continued for 6 months, caused a dose-related restoration of the number of [3H]-QNB binding sites, primarily in the CA1 and CA2 fields and in lesser amounts of the dentate gyrus. The possibility that the therapeutic effects of hydergine administration on memory function in the elderly might be related to an effect on cholinergic muscarinic receptors of the ageing hippocampus is discussed.
Aging↗