Protocol for improving the morphology of frozen sections of nervous and muscular tissue.
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Frozen Sections↗
Biomedical subjects
C Cavallotti
Publications and source records attributed to C Cavallotti.
3H-spiroperidol binding sites in the rabbit superior mesenteric artery. A histoautoradiographic study.
The distribution of 3H-spiroperidol binding sites within rabbit superior mesenteric artery was studied in normal as well as 6-hydroxydopamine (6-OHDA) sympathectomized animals using a histoautoradiographic technique. The labelled drug was located in the three layers of the artery (adventitia, media and intima), with the greater density in the media. In the adventitia the radiolabelled drug was located at the level of fibrous and connective cells. In the media 3H-spiroperidol was bound by smooth muscle cells and is found in the cellular membrane of the same cells. 6-OHDA administration causes an increase in the number of 3H-spiroperidol binding sites in the adventitia and as well as a 20-25% increase in the media. The possible existence of a direct dopaminergic innervation of the superior mesenteric artery is discussed.
Animals↗
Localization of dopamine receptors in the rabbit renal artery: a histoautoradiographic study.
The localization of dopamine receptors within rabbit renal artery was studied using 3H-spiroperidol as a label for dopamine receptors and a histoautoradiographic technique. Preliminary radioreceptor binding studies showed that 3H-spiroperidol was bound to sections of renal artery in a manner consistent with the existence of dopamine receptors. In fact the binding was found to be saturable, stereospecific and of high affinity, with a Bmax approximately of 158.3 fmol/mg protein and a Kd of 13.5 nmol/l. The microscopic examination of sections processed for the histoautoradiographic demonstration of 3'-spiroperidol binding sites showed that the distribution of dopamine receptors in the renal artery was widespread. The highest concentration of dopamine receptors was found primarily in the smooth muscle cells of the media and then, in the following order, in endothelial cells of the intima and in fibrous and connective cells of the adventitia. The direct demonstration of dopamine receptors in the media of rabbit renal artery strongly supports the hypothesis that these receptors may be involved in the relaxation of the artery caused by infusion or application of dopamine.
Animals↗
Regional distribution of cholinergic nerves in rat parietal pericardium.
The innervation pattern of parietal pericardium was studied in normal as well as chemically sympathectomized rats using the cholinesterase histochemical method. The existence of important regional variations in the distribution of cholinergic nerves within various portions of parietal pericardium studied was observed. The atria appear more richly innervated than ventricles, while the innervation of atria is characterized by the existence of thin and thick cholinergic nerve fibers not organized in plexuses and of elbow-shaped acetylcholinesterase cholinergic nerve fibers. Small blood vessels and islands of adipocytes receive a cholinergic innervation as well. The chemical sympathectomy does not alter the pattern of stained cholinergic nerve fibers. A possible afferent significance of the atrial innervation is discussed.
Acetylcholinesterase↗
Dopamine-sensitive adenylate cyclase in rabbit renal artery.
The effect of dopamine on 3',5'-cyclic adenosine monophosphate (cAMP) generation in the rabbit renal artery was studied. Dopamine added to homogenates of rabbit renal artery increased the concentration of cAMP. The stimulation of cAMP levels elicited by dopamine was remarkably reduced by the dopamine receptor antagonists fluphenazine and haloperidol, but it was unaffected by the ergot-like dopaminergic agonist bromocriptine. These findings appear to indicate that the effects of dopamine on rabbit renal artery are mediated through a D1 receptor.
Adenylyl Cyclases↗
Stimulatory effect of beta-estradiol treatment on GABA-degradative enzymes within rat cerebellar cortex.
The influence of neonatal beta-estradiol treatment on the development of GABA-degradative enzymes (GABA transaminase and succinic semialdehyde dehydrogenase) within rat cerebellar cortex has been studied using a semiquantitative histochemical technique. Both enzymatic activities were stimulated following beta-estradiol treatment. In particular, the granule and Purkinje cells were the most influenced cerebellar components. The findings seem to suggest that granule and Purkinje cells may represent the principal target of the cerebellar cortex for sex hormones.
4-Aminobutyrate Transaminase↗
Beta-adrenoceptors in the rat kidney. Immunohistochemical study.
The direct histochemical detection of beta-blocker binding sites was studied in sections of rat kidney using an immunohistochemical technique developed in our laboratory. Frozen sections of rat kidney were incubated in a solution of (-)alprenolol, washed, exposed to fluorescent (-)alprenolol antibodies (FAA) and then observed at a fluorescence microscope. Strong fluorescence was found within the wall of renal artery and vein, but primarly in the artery. At the level of blood vessels (-)alprenolol binding sites were located chiefly in the media and in the intima. The renal glomerulus, the loop of Henle and collecting tubules appear to be free of any fluorescence. Consequently they do not have beta-adrenoceptors. On the contrary, the glomerular afferent and afferent arterioles, the cellular elements of the juxtaglomerular apparatus, proximal and distal convoluted tubules, are rich in (-)alprenolol binding sites. At higher magnifications the immunoreactivity appears to be located in the basal membrane of cellular elements which indicates that (-)alprenolol binding sites are membrane receptors. The direct immunohistochemical detection of beta-blocker binding sites in the kidney may offer useful information concerning the site of action of beta-blockers at the level of an important target organ for this class of drugs.
Animals↗
The autonomic innervation of the human greater saphenous vein.
The existence of a double catecholaminergic and cholinergic innervation was demonstrated in the human greater saphenous vein. Catecholamine-containing nerve fibres are organized in a network-like plexus localized at the adventitial-medial border. Acetylcholinesterase-containing nerve fibres are arranged in a plexus found at the adventitial-medial border as well. Catecholamine and acetylcholinesterase-containing nerve fibres, while localized in close apposition since they occupy the same portion of the vein, represent two distinct and independent populations of nerve fibres coming likely from the sympathetic and parasympathetic sections of the autonomic nervous system respectively. Our findings demonstrating a close relationship between catecholaminergic and cholinergic nerve fibres within the wall of the human greater saphenous vein offer morphological support to physiological and pharmacological results reported in the literature of a presynaptic control exerted by cholinergic nerves on norepinephrine release at the level of the saphenous vein.
Acetylcholinesterase↗
The cholinergic innervation of human pancreatic islets.
The cholinergic innervation of pancreatic islets was investigated in the human using operatory samples. In order to analyze the nature of stained cholinergic nerve fibers some specimens were incubated in a solution containing 6-hydroxydopamine (6-HDA) to obtain a selective degeneration of adrenergic nerves. Cholinergic nerve fibers are present in human pancreatic islets, and appear to be organized in an external peri-insular plexus. Some nerve fibers from the peri-insular plexus enter the islets and seem to innervate directly various types of endocrine insular elements. The 6-HDA treatment does not alter the distribution pattern of cholinergic nerve fibers within pancreatic islets.
Acetylcholinesterase↗
Cholinergic innervation of the human pulmonary circulation.
The cholinergic innervation of the pulmonary circulation was studied in man. Both extra- and intrapulmonary branches of the pulmonary artery and vein are provided with a cholinergic of the vein. In the main branches of the pulmonary vessels, the existence of two nerve plexuses, a superficial and a deep one, was observed. The superficial plexus is localized in the outer adventitial layer while the deeper plexus is localized in the adventitial-medial transitional zone. In smaller arteries and veins, the existence of a single plexus (adventitial-medial) was observed. In some specimens, the presence of diffuse masses of acetylcholinesterase (AChE)-positive material or elbow-shaped AChE-positive formations was observed. The nature of these formations as well as the possible functional role of a cholinergic system in the pulmonary circulation are discussed.
Acetylcholinesterase↗
The autonomic innervation of rat jugular vein.
The autonomic innervation of rat jugular vein was studied using glyoxylic acid fluorescence and acetylcholinesterase histochemical methods. The rat jugular vein is provided with both adrenergic and cholinergic nerve fibers organized in plexuses located at the adventitial-medial border. The existence of these nerve plexuses does not seem to support biochemical findings that suggests a lack of innervation in the rat jugular vein and which propose this blood vessel as a model for the analysis of drug-smooth muscle cell interaction without the interference of neuronal uptake mechanisms.
Acetylcholinesterase↗
Innervation pattern of inferior vena cava in mouse and rat.
The innervation pattern of rat and mouse inferior vena cava was studied using catecholamine fluorescence and cholinesterase histochemical methods. Adrenergic nerve fibers innervate only abdominal portions of the inferior vena cava, while cholinergic nerves are chiefly distributed to the thoracic inferior vena cava and show a gradual decrease in the abdomen. Chemical sympathectomy performed with the neurotoxin 6-hydroxydopamine does not alter the pattern of cholinergic innervation of the inferior vena cava, suggesting the parasympathetic nature of cholinergic nerves.
Adrenergic Fibers↗
Cholinergic nerves in mouse uterus.
The topographical distribution of cholinergic nerve fibres in the uterus was studied in normal as well as chemically sympathectomized mice. Our analysis was performed using both transverse sections and whole mounts, in order to analyse the distribution of cholinergic nerves within the various layers of the uterus and to study the morphology of nerve plexuses that supply the organ. Cholinergic nerve fibres were found chiefly around the uterine artery and its primary ramifications. Nerve fibres coming from arterial plexuses are distributed to the myometrium and more infrequently to the endometrium. Groups of acetylcholinesterase positive ganglion cells were located in the cervix. The distribution pattern of the cholinergic innervation of mouse uterus shows important topographical differences. In the tubal end of uterine horn the innervation is poor and cholinergic nerve fibres are organized in a sparse plexus. The number and the density of uterine nerves increase gradually proceeding toward the cervix. The cervix shows the richest innervation. The findings that observed nerve fibres are unaltered by chemical sympathectomy and are revealed using short incubation times suggest their parasympathetic nature.
Acetylcholinesterase↗
Cholinergic nerves in the parietal pleura.
Using the cholinesterase histochemical technique we investigated the innervation pattern of parietal pleura both in normal and chemically sympathectomized rats. AChE containing nerve fiber-like structures were observed within the parietal pleura. The apex, costal, and mediastinal surfaces of the pleura are poorly innervated, while the diaphragmatic pleura shows the richest innervation. In relation with thicker nerve fiber-like structures the existence of some elbow shaped AChE positive formation was observed. The chemical sympathectomy does not causes alterations in the distribution of AChE containing nerves in the pleura. The meaning of cholinergic innervation of parietal pleura is discussed.
Acetylcholinesterase↗
Nerve fibers with a selective affinity for quinacrine in the cornea.
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Animals↗
Direct immunohistochemical detection of binding sites for beta-blocker within rat cerebellum.
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Alprenolol↗
Cholinergic nerves in the human liver.
The cholinergic innervation of the human liver was studied. Slices (150--200 micrometer thick) of human liver and of the greater hepatic blood vessels (hepatic artery and vein, portal vein) were incubated in a solution of 6-hydroxydopamine (6-HDA) in order to obtain a selective degeneration of adrenergic nerves. Controls were prepared from samples incubated with buffer alone. The slices were cut on a cryostat into 15-20 micrometer thick sections and processed for the histochemical detection of cholinesterases. Cholinergic nerve fibres innervate the extra hepatic and the intrahepatic branches of the hepatic artery, the portal vein as well as the hepatic vein. Fewer cholinergic fibres innervate the hepatocytes and the hepatic sinusoids. The 6-HDA treatment does not seem to alter the pattern of the cholinergic innervation of the liver. The findings indicate the presence of a cholinergic parasympathetic innervation in the human liver.
Acetylcholinesterase↗
Acetylcholinesterase containing nerve fibers in guinea pig ovary.
The distribution of acetylcholine esterase (AChE) in the ovary of normal as well as of sympathectomized guinea pigs was studied. In normal animals AChE-positive nerve fibres were found organized in a perivascular plexus. Some nerve fibres reach the corpus luteum and the follicular wall. Chemical sympathectomy performed with he neurotoxin 6-hydroxydopamine caused an almost complete disappearance of AChE positive nerve fibres suggesting that most of the AChE activity of ovarian nerves is localized in adrenergic nerve fibres. Enzyme activity was also present in smooth muscle cells of the vascular tree.
Acetylcholinesterase↗