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Biomedical subjects

J Rodrigo

Publications and source records attributed to J Rodrigo.

At least 109 records · Page 6Linked to original sources
PubMed1986

Occurrence, distribution and ontogeny of CGRP immunoreactivity in the rat lower respiratory tract: effect of capsaicin treatment and surgical denervations.

The occurrence and distribution of calcitonin gene-related peptide (CGRP) immunoreactivity in the rat respiratory tract were investigated by means of immunocytochemistry and radioimmunoassay using antibodies raised in rabbits to synthetic rat CGRP. Substantial amounts of CGRP immunoreactivity (range 5-37 pmol/g) were detected in all parts of the respiratory tract, the highest being in the stem bronchus. Gel filtration chromatography of extractable CGRP immunoreactivity revealed one single peak, eluting at the position of synthetic rat CGRP. CGRP immunoreactivity was localized both in mucosal endocrine cells and nerve fibres from the larynx down to the peripheral lung. CGRP-immunoreactive endocrine cells were found singly in trachea and stem bronchi and in groups in intrapulmonary airways. They appeared at a late stage of gestation (17 days), reached a maximum number near term and decreased after birth to maintain a population similar to that of the adult animals by postnatal day 21. Similarly, CGRP-immunoreactive nerve fibres were first identified by day 18 of the gestation period and reached the adult distribution by postnatal day 21. CGRP-immunoreactive nerve fibres were localized among smooth muscle, seromucous glands, beneath and within the epithelium of the airways and around blood vessels. CGRP was also found in sensory ganglia and in motor end plates of the larynx musculature. Neonatal pretreatment with capsaicin caused a marked reduction in CGRP immunoreactivity of nerve fibres in the respiratory tracts as well as a less marked decrease in the population of CGRP-containing endocrine cells of the lung. No change was seen in motor end plates immunostaining. Vagal ligation experiments revealed that CGRP-immunoreactive nerve fibres travelling in the vagus originate mainly from neurons located in the jugular ganglion. Infranodosal right vagal ligation induced a marked loss in CGRP-immunoreactive nerves of the trachea, and of the ipsilateral stem bronchus, but no changes were observed in peripheral lung. By contrast infranodosal left side vagal ligation caused a decrease in CGRP-immunoreactive nerves of the ipsilateral lung and bronchus without affecting the peptide content in the trachea. Left vagal ligation also induced a marked increase in both the intensity of staining and number of CGRP-immunoreactive endocrine cells in the lung. We conclude that CGRP immunoreactivity is localized in both nerve fibres and endocrine cells and is associated principally with the afferent (sensory) innervation of the respiratory tract.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

Calcitonin gene-related peptide (CGRP)-immunoreactive sensory and motor nerves of the mammalian palate.

The distribution of calcitonin gene-related peptide (CGRP)-immunoreactive nerve fibres in the palate of rat, cat and monkey was studied using immunocytochemistry and radioimmunoassay. CGRP-containing nerve fibres were found, in all species studied, to form a rich plexus in the subepithelial and submucous layers, around excretory ducts and blood vessels. A small number of CGRP-containing nerve fibres penetrated the epithelium of the hard and soft palate, and terminated as free endings. Some CGRP-containing nerve fibres were found in the vicinity of the mucous glands. CGRP-immunoreactive motor end plates were seen in the striated muscle (tensor veli palatini) of the soft palate. Following capsaicin treatment a small depletion in CGRP-immunoreactive nerve fibres in the rat palate epithelium was noted. In contrast, CGRP immunoreactive fibres forming rich plexuses in other layers of the palate, including motor end plates, were not affected. The extractable CGRP showed no significant depletion (normal animals [n = 10] 21.7 +/- 2.4 pmol/g compared with capsaicin-treated animals [n = 10] 17.5 +/- 1.8 pmol CGRP/g wet weight). The reduction in the number of visible immunoreactive nerves following capsaicin application tends to confirm the sensory character of the CGRP-containing nerve fibres terminating in the epithelium of the hard and soft palate. The capsaicin insensitive CGRP-immunoreactive nerve fibres may thus have a predominantly motor function.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Calcitonin gene-related peptide immunoreactive sensory and motor nerves of the rat, cat, and monkey esophagus.

In the mammalian esophagus calcitonin gene-related peptide (CGRP)-immunoreactive nerves form abundant subepithelial plexuses and penetrate the mucosa. The levels of extractable CGRP in separated epithelial layers are 15.8 +/- 2.4 pmol/g wet wt of tissue (n = 8, mean +/- SEM). Treatment of neonatal rats with capsaicin and ablation of the central portion of the feline nodose ganglion led to a marked reduction in the numbers of CGRP-immunoreactive nerve fibers. The loss of CGRP nerves demonstrated by immunocytochemistry was accompanied by a parallel reduction in the tissue content of CGRP, as measured by radioimmunoassay (1.5 +/- 0.5 pmol/g in capsaicin-treated animals compared with 9.4 +/- 1.9 pmol/g in vehicle-treated controls; p less than 0.0025). These findings indicate the sensory nature of the CGRP-immunoreactive nerves. Substance P-immunoreactive nerve fibers innervated in particular the blood vessels of the lamina propria; very few penetrated the esophageal epithelium and these were only partially depleted after removal of the central portion of the nodose ganglion. The esophageal muscle contained nerves immunoreactive for substance P and, in particular, for CGRP which was also found in the motor end plates of the striated muscle. No changes in the CGRP-containing motor end plates were observed either after treatment of neonatal rats with capsaicin or ablation of cell bodies from the central portion of the nodose ganglion. These nerve fibers may originate from rostral areas of the nucleus ambiguus, where CGRP-immunoreactive motor neurons have previously been described. Thus, our findings reveal dual components, motor and sensory, of the CGRP-containing innervation of the esophagus.

Animals↗
PubMed1985

Calcitonin gene-related peptide in cardiovascular tissues of the rat.

The distribution of calcitonin gene-related peptide immunoreactivity in the cardiovascular system of the rat was investigated by radioimmunoassay and immunocytochemistry. The nature of the immunoreactivity was studied by gel permeation and high performance liquid chromatography. Immunocytochemistry demonstrated the existence of calcitonin gene-related peptide-containing nerve fibres throughout the cardiovascular system. These were present in all regions of the heart, particularly in association with the coronary arteries, within the papillary muscles and within the sinoatrial and atrioventricular nodes. Calcitonin gene-related peptide-containing fibres were found mainly in the adventitia of the arteries and veins. Calcitonin gene-related peptide concentrations were high in major arteries and veins but comparatively low in the heart, aortic arch and thoracic aorta. Chromatography showed that approximately 70% of the total immunoreactivity was identical to synthetic calcitonin gene-related peptide. Calcitonin gene-related peptide concentrations in the blood vessels of rats treated neonatally with capsaicin were not found to be significantly different from those in control animals although capsaicin caused significant reductions of calcitonin gene-related peptide levels in certain other tissues. The results of this study suggest that calcitonin gene-related peptide-containing fibres are likely to be of importance in the innervation of vascular tissues and raise the possibility that these fibres are different in character from calcitonin gene-related peptide-containing fibres found in other tissues.

Animals↗
PubMed1985

Localisation of neuropeptide Y in nerves of the rat cardiovascular system and the effect of 6-hydroxydopamine.

The distribution of neuropeptide Y (NPY) in the rat cardiovascular system has been examined by radioimmunoassay, chromatographic analysis of tissue extracts, and immunocytochemistry. High concentrations of NPY were identified throughout the heart and within the major blood vessels of the rat in particular in the renal and superior mesenteric arteries. NPY-immunoreactivity was localised to dense plexuses of nerves in the adventitia of the arteries. Treatment of rats with 6-hydroxydopamine resulted in a significant reduction of NPY concentrations in the major vessels. A depletion of extractable NPY was also seen in the heart of the treated animals. Only few degenerated NPY-containing nerve fibres (swollen and fragmented) were observed in the heart and in the adventitia of the blood vessels. It is concluded that NPY containing nerves of the heart and blood vessels are sensitive to treatment with 6-hydroxydopamine. The pharmacological properties of this peptide suggest that these NPY-containing nerve fibres may act as efferent vasoconstrictor nerves to the blood vessels.

Adrenergic Fibers↗
PubMed1982

The functional vascular anatomy of rib.

The adequacy of nutrient blood supply to ribs based on the intercostal-periosteal system versus the medullary nutrient artery was investigated in six dogs containing ribs of each type. Free grafts with periosteum and without periosteum were also included. Vascularity was monitored by bone scanning and tetracycline double labeling. A preliminary study with RES scanning using sulfur colloid was also preformed. The results of this study showed (1) that no demonstrable difference in blood supply exists between rib supplied by the anterior intercostal-periosteal system versus the nutrient artery (this was seen with bone scans, tetracycline double labels, and RES scans); (2) that bone scans can differentiate between vascularized rib grafts and free rib grafts for at least the first 7 days (after 7 days, some free grafts begin to take up label); and (3) that by using bone scan, no difference in the rate of revascularization is detected between free grafts with the periosteum stripped or the periosteum intact (RES scans and tetracycline labeling were not given late enough after surgery to be incorporated in either type of nonvascularized graft).

Animals↗
PubMed1982

Sensory vagal nature and anatomical access paths to esophagus laminar nerve endings in myenteric ganglia. Determination by surgical degeneration methods.

The dependence, access paths and functional significance of the intraganglionic laminar nerve endings (IGLEs) in the esophageal wall of the cat are demonstrated. To this end Wallerian degeneration was induced on the vagus nerve by a number of surgical operations performed at the nodose ganglion level. The results show IGLEs to be sensorial receptors dependent on neuronal bodies situated in the nodose ganglion. The nerve fibers on which they depend to reach the esophageal wall gain access via the vagus and the superior laryngeal nerve.

Animals↗
PubMed1981

Effects of surgical sympathectomy on laminar nerve endings in myenteric ganglia.

Extirpation of the anterior regions of the sympathetic ganglionated chain (all cervical ganglia and the four subsequent thoracic ganglia) has been carried out in the cat. Histological study of the esophagus wall has shown intraganglionic laminar endings (IGLEs) to suffer an alteration which, in time, reverts to normality. Since it is not a Wallerian degeneration as such, we conclude, contrary to what has previously been assessed by some authors, that these nerve apparatuses are not dependent either on nerve cells located in sympathetic ganglia or on nerve fibers coursing through the sympathetic trunk. Speculations are made as to why IGLEs undergo a transitory alteration after experimental destruction of nerve structures to which they are not directly related.

Animals↗
PubMed1981

Ultrastructure of free-ending nerve fibres in oesophageal epithelium.

For the first time, at the ultrastructural level, the existence of free-ending, intraepithelial nerve fibres has been demonstrated in the oesophagus wall of adult cats and monkeys. Their form, the way they penetrate the epithelium, their location within the epithelium and their relationships with neighbouring cells have been established. A sensory function is suggested for this type of ending.

Animals↗
PubMed1980

New contribution on the oesophageal mucous innervation in certain monkeys (Cercopithecidae).

Spindle-shaped, barrel-like, or bush-like corpuscular neural structures situated in the mucous epithelium of the upper third of the oesophagus are described. These structures are not homogeneously distributed in this area. Some are very close to the pharyngooesophageal sphincter, spanning the thickness of the epithelium and communicating with the basal membrane by means of a thin pedicle and with the lumen by a small hilus or pore, their morphology being that of a taste bud. The others are situated deeper in the mucous epithelium of the upper third, communicating with the basal membrane only by means of either a thin pedicle or a thicker one, and separated from the lumen by a thick layer of epithelial cells. The bush-like apparatuses lie closely adjacent to the basal membrane of the epithelium.

Animals↗
PubMed1980

Sensorivagal nature of oesophageal submucous layer nerve endings. Determination of surgical degeneration methods.

Two types of surgery were performed on domestic cats to establish the source and functional significance of the apparatuses we have denominated perivascular, perifascicular and free endings of the oesophageal submucous layer. After extirpation of the cranial regions of the sympathetic ganglionic chain, of all the cervical ganglia and of the four proximal thoracic ganglia, no Wallerian degeneration of the concerned nerve endings was observed, thus ruling out their dependence on this neural pathway. After ablation of the central portion of the nodose ganglion, of the vagal nerve. Wallerian degeneration was observed in these nerve-ending apparatuses, thus demonstrating: (i) that these nerve apparatuses depend on perikarya situated in the nodose ganglion and (ii) that they are sensory receptors.

Animals↗
PubMed1979

Spinous leafy nerve endings in the feline stomach wall.

The Champy-Maillet ZIO technique has been applied to the study of the muscular tunic of the stomach. In the corpus and antrum pyloricum some nerve fibres end in non-capsulated expansions owning thorn-like protrusions. Their morphology is studied and a possibly functional sensory significance is proposed, on the basis of previous experimental results.

Animals↗
PubMed1976

Vegetative innervation of the esophagus. IV. Endings in the tela submucosa and tunica muscularis.

The osmium tetroxide-zinc iodide technique has been applied to the study of the tela submucosa and tunica muscularis in the esophagus of the cat and the rhesus monkey. Other than the classical terminal vegetative formation, three types of endings were found, classified as perifascicular, free and intramuscular. The comparative results between cat and rhesus monkey show differences in the distribution and number of such endings. A sensory functional significance is proposed and discussed.

Anatomy, Comparative↗
PubMed1975

Vegetative innervation of the esophagus. II. Intraganglionic laminar endings.

The intraganglionic laminar endings in the esophagus of the cat and the rhesus monkey show absolute equivalence between the results in both species from the morphological standpoint. The different types of apparatus found are described, with their location in the esophagus and their percentage distribution in relation to the different portions of its wall. The osmium tetroxide-zinc iodide technique gives pictures equivalent to those using silver impregnations, with the added advantage that the former brings out the morphological details more clearly, to the point of showing up the peculiar characteristics of the edges with their thorn-like protrusions. The complete independence of these structures within the ganglion is confirmed, and evidence is provided for rejecting the possibility that they might be dendritic prolongations of the neuronal elements composing the intramural ganglia. A possible afferent function is proposed, which, however, must be considered an open question, pending the results of further experimental investigation.

Animals↗