RESUMO
Acetylcholine (ACh) stimulates contraction of the uterus and dilates the uterine arterial supply. Uterine cholinergic nerves arise from the paracervical ganglia and were, in the past, characterized based on acetylcholinesterase (AChE) histochemistry. However, the histochemical reaction for acetylcholinesterase provides only indirect evidence of acetylcholine location and is a nonspecific marker for cholinergic nerves. The present study: (1) reevaluated cholinergic neurons of the paracervical ganglia, (2) examined the cholinergic innervation of the uterus by using retrograde axonal tracing and antibodies against molecules specific to cholinergic neurons, choline acetyltransferase and the vesicular acetylcholine transporter, and (3) examined muscarinic receptors in the paracervical ganglia using autoradiography and a radiolabeled agonist. Most ganglionic neurons were choline acetyltransferase- and vesicular acetylcholine transporter-immunoreactive and were apposed by choline acetyltransferase/vesicular acetylcholine transporter-immunoreactive terminals. Retrograde tracing showed that some cholinergic neurons projected axons to the uterus. These nerves formed moderately dense plexuses in the myometrium, cervical smooth muscle and microarterial system of the uterine horns and cervix. Finally, the paracervical ganglia contain muscarinic receptors. These results clearly reveal the cholinergic innervation of the uterus and cervix, a source of these nerves, and demonstrate the muscarinic receptor content of the paracervical ganglia. Cholinergic nerves could play significant roles in the control of uterine myometrium and vasculature.
Assuntos
Acetilcolinesterase/análise , Axônios/ultraestrutura , Colo do Útero/inervação , Colina O-Acetiltransferase/análise , Gânglios Autônomos/citologia , Receptores Muscarínicos/metabolismo , Útero/inervação , Animais , Autorradiografia , Transporte Axonal , Axônios/fisiologia , Feminino , Gânglios Autônomos/fisiologia , Gânglios Autônomos/ultraestrutura , Quinuclidinil Benzilato/farmacocinética , Ratos , Ratos Sprague-Dawley , Receptores Muscarínicos/análise , Medula Espinal/citologia , Medula Espinal/metabolismo , TrítioRESUMO
Neutral endopeptidase EC 3.4.24.11 (NEP) is localized in peptidergic neurons and various colocalized peptides or other humoral mediators may serve as substrates. Target disruption of the NEP gene was reported to enhance the lethal response to endotoxin shock in mice. We examined thermonociceptive thresholds and enkephalin (ENK) tissue levels in transgenic NEP (-/-) and control wild type NEP (+/+) mice. Hot plate (52 degrees C) latency was 13.1 +/- 1.4 s in NEP (+/+) mice (n = 16) while latency increased significantly (P = 0.031) to 17.7 +/- 1.6 s in NEP (-/-) mice. Naloxone (10 mg/kg) had no effect on hot plate latency in NEP (+/+) mice (12.5 s, n = 8), but significantly decreased the latency in NEP (-/-) mice compared to untreated NEP (-/-) deficient mice (10.5 s, n = 8). Morphine (3 or 10 mg/kg) analgesic response was similar in knockout mice and wild type mice. Methionine-ENK (MET-ENK) and leucine-ENK (LEU-ENK) levels were determined in extracts from cortex, brain stem, hypothalamus, striatum, spinal cord, trigeminal ganglion and heart in treated and untreated mice. ENK-levels varied in a regionally-dependent manner and were significantly decreased in hypothalamus and spinal cord. We conclude that deletion of the NEP gene results in an opioid-related increase in thermonociceptive threshold. Regional differences in opioid metabolism indicate that NEP evokes tissue-specific patterns of ENK-regulation. NEP selectively controls opioid biosynthesis in hypothalamus and spinal cord presumably by feedback regulation.
Assuntos
Analgésicos Opioides/farmacologia , Encefalina Leucina/metabolismo , Encefalina Metionina/metabolismo , Morfina/farmacologia , Neprilisina/genética , Limiar da Dor , Animais , Camundongos , Camundongos Knockout , Fenótipo , TemperaturaRESUMO
The ontogenic development of secretogranin II was studied by immunochemistry and immunohistochemistry. Extracts of brains from various developmental stages were analyzed by a radioimmunoassay for secretoneurin, a peptide derived from secretogranin II. From gestational day 13 to adulthood the levels increased from 0.1 to 94 fmol/mg wet weight. Characterization of the immunoreactivity by molecular sieve chromatography revealed that throughout all developmental stages the proprotein secretogranin II was fully processed to the free peptide secretoneurin. In immunohistochemistry secretoneurin-IR was first detected at embryonic day 13. Between embryonic days 14 and 18 a strong increase in the number of secretoneurin immunopositive cells was observed in many brain areas, notably in the amygdala, hypothalamus, olfactory bulb and several brainstem nuclei. The pattern of staining during development is quite similar to that in the adult. The present paper demonstrates that secretoneurin immunoreactivity appears early in embryonic life. Processing of the proprotein secretogranin II starts when the protein is first synthesized apparently at about the same time when the prohormone convertase PC1 and PC2 can be demonstrated.
Assuntos
Química Encefálica/fisiologia , Encéfalo/crescimento & desenvolvimento , Neuropeptídeos/metabolismo , Biossíntese de Proteínas , Proteínas , Animais , Animais Recém-Nascidos/fisiologia , Encéfalo/embriologia , Encéfalo/enzimologia , Cromatografia em Gel , Cromograninas , Feminino , Furina , Imuno-Histoquímica , Gravidez , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , Secretogranina II , Subtilisinas/metabolismoAssuntos
Encéfalo/embriologia , Encéfalo/metabolismo , Neuropeptídeos/metabolismo , Animais , Cromograninas , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Idade Gestacional , Imuno-Histoquímica , Hibridização In Situ , Neuropeptídeos/genética , Gravidez , Processamento de Proteína Pós-Traducional , Proteínas/genética , Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Secretogranina II , Distribuição TecidualRESUMO
PURPOSE: This study investigated the ability of autogenous pericranium-muscle and cranial bone to restore form and function of the temporomandibular joint (TMJ). MATERIALS AND METHODS: A right TMJ discectomy, condylectomy, vertical ramus osteotomy with superior repositioning of the proximal fragment, and a cranial bone graft to the mandibular angle were performed in 12 cynomolgus monkeys. Clinical, histologic, and autoradiographic evaluation was done at intervals beginning at 3 days and continuing up to 78 weeks. RESULTS: No significant postoperative sequela were identified in any of the monkeys. Jaw mobility and function were restored. Gross morphologic condylar changes were observed. The pericranium-muscle grafts did not differentiate into normal disc-like structures and a cartilage cap did not cover the condyle stump head. CONCLUSIONS: The results of this study suggest that the previous TMJ function was restored. However, the histologic changes observed were consistent with advanced degenerative joint disease.
Assuntos
Transplante Ósseo/métodos , Articulação Temporomandibular/cirurgia , Animais , Autorradiografia , Seguimentos , Macaca fascicularis , Osteotomia/métodos , Periósteo/transplante , Crânio , Técnicas de Sutura , Articulação Temporomandibular/patologia , Fatores de Tempo , Transplante AutólogoRESUMO
BACKGROUND: The paracervical ganglia (PG) are components of the pelvic plexus that provides sensory and motor innervation to the reproductive system of the female rat. Several neurotransmitters including norepinephrine (NE), acetylcholine (ACh), neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP) are present in neurons of the adult PG and in axons innervating the adult uterus and uterine cervix. The current study was undertaken to describe the onset of immunoreactivity of these neurotransmitters and neuropeptides during development. METHODS: Female rats, ages E18 to P36, were prepared for immunohistochemistry for TH (tyrosine hydroxylase, a marker of noradrenergic neurons), NPY, or VIP as well as the histochemical demonstration of acetylcholinesterase (AChE). RESULTS: All four markers were detected in neurons of the PG at E18. Changes in the appearance of these markers from E18 to P36 reflected previously described growth changes in the PG. Axons containing AChE, TH, NPY, or VIP were first detected within the cervix at E20. Immunopositive axons first appeared as thick, unbranched structures at the outermost portion of the cervical myometrium. Over time, these axon bundles ramified to form discrete varicose axons. The ingrowth was similar for axons containing each of the four markers. CONCLUSIONS: The relative density of each neuronal type in the PG was reflected in the density of axons containing the same marker in the cervix. Changes in neurotransmitter/neuropeptide staining of PG neurons or axons in the cervix were not observed as the animals approached puberty.
Assuntos
Colo do Útero/inervação , Plexo Hipogástrico/química , Neurônios/química , Neurotransmissores/análise , Acetilcolinesterase/análise , Animais , Colo do Útero/citologia , Colo do Útero/embriologia , Colo do Útero/crescimento & desenvolvimento , Feminino , Plexo Hipogástrico/citologia , Plexo Hipogástrico/embriologia , Plexo Hipogástrico/crescimento & desenvolvimento , Imuno-Histoquímica , Neurônios/citologia , Neuropeptídeo Y/análise , Ratos , Ratos Sprague-Dawley , Tirosina 3-Mono-Oxigenase/análise , Peptídeo Intestinal Vasoativo/análiseRESUMO
The expressions of two closely related synaptic vesicle antigens synaptophysin and synaptoporin were examined in the olfactory system of the adult rat and during pre- and postnatal development. In the adult, immunocytochemistry showed that the continuously regenerating olfactory receptor neurons (primary neurons) produce both synaptophysin and synaptoporin which were localized in the cell bodies of the receptor neurons in the olfactory epithelium, their dendrites, axonal processes in the olfactory nerve and their terminals in the olfactory bulb glomeruli. Furthermore, ultrastructural analysis revealed synaptophysin- and synaptoporin-immunoreactivities associated with synaptic vesicles in most olfactory receptor axonal terminals impinging on dendrites of the mitral and tufted neurons (secondary neurons in the olfactory bulb circuitry) in the olfactory glomeruli. In like manner, tufted neurons, granule and periglomerular neurons (interneurons in the olfactory bulb circuitry) express both synaptophysin and synaptoporin. In contrast, mitral neurons expressed only the synaptophysin antigen which was likewise associated with mitral axonal terminals in their target the olfactory cortex. The patterns of synaptophysin and synaptoporin expressions in mitral neurons (synaptophysin only) and tufted neurons (synaptophysin and synaptoporin) were similar in prenatal, postnatal and adult rats as revealed by immunocytochemistry and in situ hybridization. However, the biosynthesis of synaptophysin and synaptoporin by granule and periglomerular neurons, olfactory bulb interneurons, occurred mainly postnatally.
Assuntos
Proteínas de Membrana/biossíntese , Neurônios Aferentes/metabolismo , Córtex Somatossensorial/metabolismo , Sinaptofisina/biossíntese , Animais , Feminino , Imuno-Histoquímica , Hibridização In Situ , Interneurônios/metabolismo , Interneurônios/ultraestrutura , Masculino , Terminações Nervosas/metabolismo , Terminações Nervosas/ultraestrutura , Neurônios Aferentes/ultraestrutura , Bulbo Olfatório/metabolismo , Bulbo Olfatório/ultraestrutura , Nervo Olfatório/metabolismo , Nervo Olfatório/ultraestrutura , Gravidez , Terminações Pré-Sinápticas/metabolismo , Terminações Pré-Sinápticas/ultraestrutura , Ratos , Ratos Sprague-Dawley , Córtex Somatossensorial/embriologia , Córtex Somatossensorial/ultraestrutura , Vesículas Sinápticas/metabolismo , Vesículas Sinápticas/ultraestruturaAssuntos
Vias Aferentes/fisiologia , Sistema Nervoso Autônomo/fisiologia , Substância P/análogos & derivados , Substância P/fisiologia , Útero/inervação , Vias Aferentes/efeitos dos fármacos , Animais , Feminino , Humanos , Modelos Biológicos , Medula Espinal/fisiologia , Substância P/farmacologia , Contração Uterina/efeitos dos fármacosRESUMO
The presence and distribution of galanin-immunoreactivity was examined in the uterine cervix and paracervical autonomic ganglia of the female rat. Some animals were treated with capsaicin to determine if galanin-immunoreactivity was present in small-diameter primary afferent nerves. Other animals were treated with the noradrenergic neurotoxin 6-hydroxydopamine to ascertain if galanin-immunoreactivity was present in sympathetic noradrenergic nerves. Galanin-immunoreactive nerve fibers were sparse in the cervical myometrium and vasculature, but numerous in the paracervical ganglion where they appeared to innervate principal neurons. Immunoreactivity was also present in dorsal root ganglia, dorsal horn of spinal cord, and inferior mesenteric ganglia. Capsaicin treatment resulted in a marked reduction of galanin-immunoreactivity in the spinal cord dorsal horn, but not in the dorsal root ganglia, paracervical ganglia, or cervix (although there was a substantial reduction of substance P-, neurokinin A-, and calcitonin gene-related peptide-immunoreactivity in the dorsal horn. dorsal root ganglia, and uterine cervix). 6-Hydroxydopamine treatment did not cause any appreciable change in the galanin-immunoreactivity in any tissues. We conclude that galanin-like immunoreactivity is expressed in nerve fibers innervating the paracervical ganglia and uterine cervix of the female rat. This immunoreactivity is probably present in afferent nerves and could play a role in neuroendocrine reflexes and in reproductive function.
Assuntos
Sistema Nervoso Autônomo/metabolismo , Capsaicina/farmacologia , Colo do Útero/inervação , Gânglios Espinais/metabolismo , Peptídeos/imunologia , Animais , Sistema Nervoso Autônomo/citologia , Sistema Nervoso Autônomo/efeitos dos fármacos , Feminino , Galanina , Gânglios Espinais/citologia , Gânglios Espinais/efeitos dos fármacos , Neurônios Aferentes/citologia , Neurônios Aferentes/efeitos dos fármacos , Neurônios Aferentes/metabolismo , Ratos , Ratos EndogâmicosRESUMO
Condylar shaves were performed in monkeys, and the reparative process was studied by histologic and autoradiographic techniques. The condylar surface was found to repair mainly with fibrous connective tissue produced by cells derived from the underlying marrow spaces. The residual condylar cartilage did not play a significant role in this process.
Assuntos
Cartilagem Articular/cirurgia , Côndilo Mandibular/cirurgia , Articulação Temporomandibular/cirurgia , Animais , Autorradiografia , Cartilagem Articular/anatomia & histologia , Cartilagem Articular/citologia , Divisão Celular , Tecido Conjuntivo/anatomia & histologia , Células do Tecido Conjuntivo , Criocirurgia , Feminino , Fibroblastos/citologia , Macaca fascicularis , Côndilo Mandibular/anatomia & histologia , Côndilo Mandibular/citologia , Osteoblastos/citologia , Osteócitos/citologia , Articulação Temporomandibular/anatomia & histologia , Articulação Temporomandibular/citologia , CicatrizaçãoRESUMO
Nerves immunoreactive for the peptides substance P, neurokinin A, calcitonin gene-related peptide or cholecystokinin-octapeptide innervate the uterine cervix in the rat. Nerve terminals are associated with the myometrial and vascular smooth muscle and are distributed throughout the endocervix. These nerves degenerate following neonatal capsaicin treatment indicating that they are small-diameter, unmyelinated, C-type primary afferent nerves. Adult female rats, treated with capsaicin as neonates, exhibit decreased fertility following mating and diminished sensitivity to the induction of pseudopregnancy following copulomimetic electrical stimulation of the cervix. The results also demonstrate that hypothalamo-adenohypophyseal-ovarian interactions, corpus luteum progesterone secretion and uterine sensitivity to progesterone are normal in capsaicin-treated rats. Taken together, these data suggest that the reproductive dysfunction observed in capsaicin-treated rats is due to destruction of the afferent limb of the neuroendocrine copulatory response that facilitates the luteal progesterone secretion necessary to support pregnancy or pseudopregnancy. Thus, it is concluded that the afferent limb of this neuroendocrine response in the rat consists primarily of unmyelinated, peptide-containing, C-type primary afferent nerves.
Assuntos
Capsaicina/farmacologia , Colo do Útero/inervação , Copulação/fisiologia , Neurônios Aferentes/fisiologia , Reprodução/efeitos dos fármacos , Animais , Feminino , Fertilidade , Imuno-Histoquímica , Metiltirosinas/farmacologia , Microscopia Eletrônica , Neurônios Aferentes/análise , Neurônios Aferentes/ultraestrutura , Sistemas Neurossecretores/fisiologia , Peptídeos/análise , Peptídeos/imunologia , Progesterona/metabolismo , Progesterona/farmacologia , Pseudogravidez/induzido quimicamente , Radioimunoensaio , Ratos , Ratos Endogâmicos , alfa-MetiltirosinaRESUMO
Nerves in the uterine cervix of the rat were examined with regard to co-existence of markers for noradrenaline and neuropeptide Y, and differential tissue innervation by nerves containing different combinations of these markers. Immunohistochemical labeling of single and adjacent serial cryostat sections, and double labeling was employed. Some animals were treated with the noradrenergic neurotoxin, 6-hydroxydopamine. In control animals neuropeptide Y-immunoreactive fibers were numerous in the myometrium and around arteries; noradrenergic fibers were few in the myometrium and moderate in number around arteries. Myometrial neuropeptide Y-immunoreactive fibers were not decreased, but apparently increased, in 6-hydroxy-dopamine-treated rats; in contrast, perivascular neuropeptide Y-immunoreactive fibers were markedly reduced, but not totally absent. Noradrenergic fibers were absent in the myometrium and around arteries following 6-hydroxydopamine treatment. Labeling of adjacent sections and double labeling revealed coincident labeling of markers for neuropeptide Y and noradrenaline in perivascular, but not myometrial, nerves. We concluded that most myometrial neuropeptide Y-immunoreactive nerves did not contain noradrenaline since they were not sensitive to 6-hydroxydopamine and did not stain doubly; however, perivascular neuropeptide Y-immunoreactive fibers which degenerated after 6-hydroxydopamine treatment and did label doubly must co-store noradrenaline. Some neuropeptide Y-immunoreactive perivascular fibers may contain neuropeptide Y but not noradrenaline. Thus, it appears there is a differential innervation of tissues in the cervix by neuropeptide Y/noradrenergic nerves; this could reflect a differential regulation of tissues innervated by these nerves.
Assuntos
Colo do Útero/inervação , Fibras Nervosas/citologia , Neuropeptídeo Y/análise , Norepinefrina/análise , Animais , Colo do Útero/citologia , Feminino , Imunofluorescência , Gânglios/citologia , Hidroxidopaminas/farmacologia , Miométrio/inervação , Neuropeptídeo Y/imunologia , Oxidopamina , Ratos , Ratos Endogâmicos , Valores de ReferênciaRESUMO
The techniques of conventional discoplasty and the scar producing potential of cryosurgical treatment of the bilaminar region were examined in a study of 17 adult female cynomologous monkeys. Temporomandibular joint (TMJ) tissues were obtained at four and 10 days, four, 20, 52, and 78 weeks after surgery, and compared to TMJ tissues in unoperated control animals. No clinically observable changes in weight, occlusion, or jaw function were identified. All the surgical sites healed normally. At necropsy, lesions of the articular surface of the condyle were apparent in areas that had been surgically "shaved." The anterior, intermediate, and posterior zones of the surgically-treated discs were generally free of change. Two cryosurgically-treated discs showed lesions and perforations. Histologic and autoradiographic observations suggested that the bilaminar area heals quickly with minimal scarring, following both conventional surgical manipulation and cryosurgery. Under the conditions of this experiment the cryosurgical technique was judged not to be superior to the conventional surgical approach.
Assuntos
Cartilagem Articular/cirurgia , Criocirurgia , Articulação Temporomandibular/cirurgia , Animais , Autorradiografia , Cartilagem Articular/citologia , Divisão Celular , Colágeno , Células do Tecido Conjuntivo , Feminino , Macaca fascicularis , Côndilo Mandibular/citologia , Osso Temporal/citologia , Articulação Temporomandibular/citologia , CicatrizaçãoRESUMO
The paracervical ganglia of the female rat were studied to elucidate the variety of neural elements in the ganglia. Light and electron microscopy, histochemistry, and immunohistochemistry were employed to reveal subtypes of neurons; small, intensely fluorescent (SIF) cells; and nerve terminals and to examine the relationships between these elements. On the basis of their histochemical markers, four subtypes of principal neurons were identified: acetylcholinesterase (ACHE)-positive, noradrenergic, neuropeptide tyrosine-immunoreactive (NPY-I), and vasoactive intestinal polypeptide-immunoreactive (VIP-I). The NPY-I neurons appeared to be the most numerous and the noradrenergic the least common type of neuron. Four subtypes of chemically coded SIF cells were revealed: catecholamine-containing, NPY-I, and those immunoreactive for calcitonin-gene-related peptide (CGRP-I) and cholecystokinin-octapeptide (CCK-8-I). The SIF cells were present as single cells among and adjacent to principal neurons and as large clusters near the edges of the ganglia or in nearby nerve trunks. Synaptic contacts on SIF cells, or between SIF-cell processes and neurons, were not observed. Seven subtypes of nerve terminals were stained: ACHE-positive, CGRP-I, CCK-8-I, VIP-I, substance P-I, enkephalin-I, and atrial natriuretic factor-I. Nerve terminals enwrapped the neurons as perineuronal plexuses in synaptic-like relationships. These results demonstrate that the paracervical ganglia of the female rat are a complex system of neural elements. For example, several classes of chemically coded neurons, SIF cells, and terminals exist in the ganglia. Each of these components contains a number of substances, some of which are putative neurotransmitters, which could influence activity in the ganglia or in the effector organs innervated by the ganglia.
Assuntos
Colo do Útero/inervação , Gânglios Autônomos/fisiologia , Gânglios/citologia , Acetilcolinesterase/metabolismo , Animais , Catecolaminas/metabolismo , Feminino , Gânglios Autônomos/anatomia & histologia , Histocitoquímica , Imunoquímica , Microscopia de Fluorescência , Neuropeptídeo Y/metabolismo , Neurotransmissores/fisiologia , Tirosina 3-Mono-Oxigenase/metabolismo , Peptídeo Intestinal Vasoativo/metabolismoRESUMO
Enkephalin- and atrial natriuretic factor-like immunoreactivities were localized in nerve terminals in the female rat paracervical ganglia. Immunoreactive terminals were adjacent to and in synaptic contact with many, but not all, principal neurons. Immunoreactivity was restricted to large dense-core synaptic vesicles. These results suggest that there is a complex synaptic input to the principal neurons of the rat paracervical ganglia and that these substances could act as neurotransmitters or neuromodulators in the ganglion.
Assuntos
Fator Natriurético Atrial/metabolismo , Encefalinas/metabolismo , Gânglios Autônomos/metabolismo , Genitália Feminina/inervação , Animais , Catecolaminas/metabolismo , Feminino , Imunofluorescência , Gânglios Autônomos/citologia , Microscopia Eletrônica , Terminações Nervosas/metabolismo , Ratos , Ratos EndogâmicosRESUMO
With the use of the peroxidase-antiperoxidase technique the distribution of substance P (SP), enkephalin (ENK), and serotonin (5HT) immunoreactivities were described in the area postrema of the rat and cat. In both species, immunoreactivity in the area postrema was differentially distributed as either fibers only, or cell bodies and fibers. In the rat and cat, ENK had the greatest accumulation of immunoreactive fibers, followed by 5HT and SP. In the area postrema of the rat the majority of SP-, ENK-, and 5HT-immunoreactive fibers were along the ventral and ventrolateral borders, with fewer immunostained fibers at the dorsal surface. The area postrema of the cat had the majority of SP-, ENK-, and 5HT-immunoreactive fibers at the ventral and lateral borders, with fewer immunostained fibers at the dorsal and medial borders. In both species, the area postrema's central region contained the fewest immunostained fibers. In general, for each putative neurotransmitter examined, immunostained fibers in both species progressively decreased in number rostrocaudally. Serotonin- and ENK-immunoreactive cell bodies were found in the rat area postrema; in the cat area postrema only ENK-immunoreactive cell bodies were present. The area postrema of both species lacked SP-immunoreactive cell bodies. The heterogeneous distribution of immunoreactive fibers and cell bodies within the area postrema of the rat and cat may reflect the different functions of the area postrema in both species.
Assuntos
Tronco Encefálico/metabolismo , Encefalinas/metabolismo , Sistemas Neurossecretores/metabolismo , Serotonina/metabolismo , Substância P/metabolismo , Animais , Tronco Encefálico/fisiopatologia , Gatos , Técnicas Imunoenzimáticas , Masculino , Sistemas Neurossecretores/fisiopatologia , Ratos , Ratos Endogâmicos , Reflexo/fisiologia , Especificidade da Espécie , Vômito/fisiopatologiaRESUMO
The purpose of this investigation was to localize binding sites for the cardiac glycoside digoxin in the medulla of the rat in vivo. Adult male Sprague-Dawley rats were injected (IV) with 3H-digoxin and killed 30 minutes later. Autoradiographs of medullas showed evidence of 3H-digoxin binding to small- and medium-sized neural cells in the regions of the nucleus solitarius, dorsal motor nucleus of the vagus, area postrema, and in the zone between the area postrema and the underlying neuropil. However, the parasympathetic preganglionic neurons of the dorsal motor nucleus were not labeled. The 3H-digoxin-labeled cells in the medulla were located mainly in the commissural and medial portions of nucleus solitarius at the level of the area postrema. Animals injected with unlabeled digoxin followed by 3H-digoxin showed reduced binding of radioactivity. The small- and medium-sized neurons of the caudal portions of the nucleus solitarius are internuncial in position with respect to cardiovascular afferents of the glossopharyngeal and vagus nerves and sympathetic and parasympathetic cardiovascular efferent neurons of the medulla. The results of this study suggest that these 3H-digoxin-labeled cells, presumably neurons of nucleus solitarius, may possess high affinity binding sites for digoxin. Further, the area postrema, which lacks a blood-brain barrier, may provide a portal of entry for 3H-digoxin into regions of the medulla known to contain neurons that play a role in the regulation of cardiac rhythm.
Assuntos
Digoxina/metabolismo , Bulbo/metabolismo , Animais , Autorradiografia , Sítios de Ligação , Masculino , Bulbo/citologia , Neurônios/metabolismo , Ratos , Ratos Endogâmicos , Distribuição Tecidual , TrítioRESUMO
Location, distribution and density of nerve fibers immunoreactive to neuropeptide tyrosine, vasoactive intestinal polypeptide and substance P were studied in the reproductive tract of the female rat and compared with acetylcholinesterase-positive ("cholinergic") and noradrenergic nerves. Plexuses of all types of fibers were present in the vagina, uterine cervix, uterine horn and oviduct. In the tubular reproductive organs all of these types of nerve fibers appeared to innervate vascular and non-vascular smooth muscle and nearly all types of fibers formed plexuses subjacent to the epithelium lining the organs. Individual fibers of all classes appeared to innervate fascicles of smooth muscle in the mesometrium of the uterine horn. A few acetylcholinesterase-positive and substance P-immunoreactive fibers were present in the ovary but no vasoactive intestinal polypeptide-immunoreactive nerves were observed. Noradrenergic and neuropeptide tyrosine-immunoreactive nerves were numerous in the ovary where they were seen in the interstitial gland tissue and associated with follicles and blood vessels. It is suggested that these nerves may influence hemodynamic events and non-vascular smooth muscle in such functions as transport of sperm and ova and parturition. Substance P-immunoreactive nerve fibers are likely to be sensory fibers that could have roles in neurohormonal reflexes.
Assuntos
Acetilcolinesterase/análise , Genitália Feminina/inervação , Proteínas do Tecido Nervoso/análise , Norepinefrina/fisiologia , Substância P/análise , Sistema Nervoso Simpático/metabolismo , Tirosina/análise , Peptídeo Intestinal Vasoativo/análise , Animais , Feminino , Genitália Feminina/citologia , Histocitoquímica , Especificidade de Órgãos , Ratos , Ratos Endogâmicos , Sistema Nervoso Simpático/citologiaRESUMO
Tissue concentrations of substance P immunoreactivity (SP-I) were measured in rat mammary nipples and were significantly greater than in ventral abdominal skin in nonpregnant and pregnant rats. In contrast, the concentration of nipple SP-I was lower than that of skin in twelve day lactating animals. The mean total SP-I content of the pooled twelve nipples from each rat was not significantly different in nonpregnant, pregnant or lactating rats. However, the mean weight of the pooled twelve nipples from each rat was significantly higher in the lactating rats than in pregnant rats. Immunohistochemistry revealed SP-I nerve trunks and single fibers throughout the nipples of lactating rats. Nerve fibers were observed among smooth muscle and along blood vessels throughout the dermis and in association with epidermal structures. Some SP-I fibers were also observed in association with the main lactiferous duct and mammary gland secretory parenchyma. Radioimmunoassay and immunohistochemistry of nipples from lactating rats treated with capsaicin as neonates revealed a marked depletion of SP-I. Rats treated with capsaicin as neonates had a normal gestation period and produced litters of normal size and birth weight. However, the litters of these lactating rats grew at a significantly slower rate than litters from controls. The quantity of milk obtained from capsaicin-treated lactating dams, following a one hour suckling period on the twelfth day of lactation, was significantly less than that obtained by litters of control dams. It is concluded that capsaicin-sensitive primary sensory nerves of the mammary nipple play a role in the afferent limb of the suckling reflex. One transmitter candidate for these nerves is substance P.
Assuntos
Mama/metabolismo , Capsaicina/farmacologia , Lactação/efeitos dos fármacos , Glândulas Mamárias Animais/metabolismo , Mamilos/metabolismo , Substância P/metabolismo , Animais , Feminino , Histocitoquímica , Imunoquímica , Neurônios/metabolismo , Mamilos/inervação , Gravidez , Radioimunoensaio , Ratos , Ratos Endogâmicos , Substância P/imunologiaRESUMO
The distribution of FMRF-NH2-like immunoreactivity, visualized with immunohistochemical techniques, was plotted in a range from very dense to none. The rat area postrema had differential immunostaining with the greatest amounts occurring at its ventral and ventrolateral borders by the nucleus of the solitary tract. Immunoreactive cell bodies were located mainly in this region. Throughout the central region of the rat area postrema scattered immunostaining was consistently observed. The cat area postrema had a different, greater, and more complex pattern of immunostaining than the rat. Very dense to dense accumulations of immunostaining occurred in the ventromedial region of the area postrema bordering the solitary tract and dorsal vagal nuclei, while the central region possessed scattered amounts of immunoreactivity. Following colchicine treatment, no visible FMRF-NH2-like immunoreactive cell bodies were observed in the cat area postrema.