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Biomedical subjects

R Elde

Publications and source records attributed to R Elde.

At least 127 records · Page 7Linked to original sources
PubMed1980

Substance P, VIP, enkephalin and somatostatin immunoreactive neurons in intestinal tissue transplanted to the anterior eye chamber.

Tissue pieces of small and large intestine from pre- and postnatal and adult rats, respectively, were transplanted to the anterior eye chamber of the rat. Immunohistochemical studies revealed high numbers of substance P-, vasoactive intestinal polypeptide (VIP)- and enkephalin-containing nerve fibers, especially in the circular smooth muscle layer and in the myenteric plexus of the intestinal tissue transplants. A small number of somatostatin-containing fibers were observed. The distribution patterns of the various peptide-containing neurons in the grafts resembled those which have been described in the intact gastro-intestinal wall. Substance P, VIP, enkephalin and somato-statin immunoreactive fibers were seen also in the host irides. No obvious differences in peptide innervation in grafts and host irides were observed between normal and sympathectomized animals and animals lesioned in the trigeminal ganglion. These findings suggest that most of the peptide-containing fibers in the intestinal transplants and the host irides originate in the transplanted tissue. Thus, it is shown that peptide neurons can survive in this transplantation model, which may be useful for functional studies of intestinal physiology including peptidergic mechanisms.

Animals↗
PubMed1980

Immunohistochemical studies of peptidergic neurons in the dorsal horn of the spinal cord.

The indirect immunofluorescence technique was used to localize substance P, somatostatin, methionine--enkephalin, neurotensin, and oxytocin in the dorsal horn of the rat spinal cord. The unique distribution of each peptide is described and the relative amount of each peptide in laminae I--III of the dorsal horn and the dorsal part of the lateral funniculus qualitatively assessed. Colchicine treatment and dorsal rhizotomy were used to determine, in part, the origin of immunoreactive fibers and terminals observed in the dorsal horn.

Animals↗
PubMed1979

Localization of hypophysiotropic peptides and other biologically active peptides within the brain.

Immunohistochemical analysis of hypophysiotropic and other neuropeptides reveals unique and striking neural perikarya, axons, and terminals containing specific peptide immunoreactivity. The hypophysiotropic peptides are most highly concentrated in nerve terminals in the external layer of the median eminence. From this site they may be released and carried via the portal circulation to the adenohypophysis. The occurrence of hypophysiotropic peptides in other areas of the nervous system suggests that they may act, at these sites, as neurotransmitters. Enkephalins, SP, angiotensin II, and cholecystokinin-like immunoreactivity are also found in nerve terminals in the external layer of the median eminence of some species. Although these peptides have not been considered hypophysiotropic hormones, the location of their terminals in the median eminence suggests that they participate indirectly in regulation of anterior pituitary hormone release. This control may be accomplished via axo-axonal influences of terminals containing these peptides upon the terminals containing the genuine hypophysiotropic peptides. An analogous interaction is thought to be exerted by dopamine terminals upon LHRH terminals in the median eminence (39). All of the neuropeptides discussed above are found within neuronal structures in the hypothalamus. Most of these peptides are also found, at least to a limited extent, in the brainstem, spinal cord, and deep nuclei of the telencephalon. Few peptides have been localized in neurons of the cerebral cortex. These include SOM, VIP, and cholecystokinin-like immunoreactivity. The cerebellum, to date, has not been shown to contain significant immunoreactivity for any of the presently identifiable neuropeptides. The demonstration of the coexistence of neuropeptides (SOM and SP) in some monoaminergic (adrenergic and serotonergic) neurons raises questions about the one-neuron-one-transmitter hypothesis. It is presently unknown whether or not such coexistence is widespread in the mammalian nervous system. For those neurons that contain two neuroeffector substances, it will be important to determine whether or not both substances play an active role in the function of the neuron. Finally, the details of the morphological interactions of peptidergic elements with other neuronal systems offer the possibility to understand more completely the circuitry of many regions of the central nervous system.

Animals↗
PubMed1978

Peptide neurons in peripheral tissues including the urinary tract: immunohistochemical studies.

Using the indirect immunofluorescence technique of Coons and collaborators, neurons containing substance P-, enkephalin-, vasoactive intestinal polypeptide (VIP)--and somatostatin-like immuno-reactivity have been identified in the peripheral nervous system. They have a widespread distribution, particularly in the gastrointestinal and urinary tracts. Whereas part of these peptide containing fibres may belong to sensory neurons, the majority seem to have their origin in peripheral autonomic ganglia, indicating a complex built up of the autonomic nervous system. There is evidence that some noradrenergic neurons contain somatostatin, which may suggest that one neuron can synthesize and store two transmitters. The significance of such neurons, as well as of peripheral peptide neurons in general, remains to be elucidated.

Angiotensin II↗
PubMed1977

Immunohistochemical analysis of peptide pathways possibly related to pain and analgesia: enkephalin and substance P.

The distribution of Met-enkephalin- and substance P-immunoreactive neurons was studied by indirect immunofluorescence in some areas related to pain and analgesia. Met-enkephalin- and substance P-positive cell bodies and nerve terminals were observed in the periaqueductal central gray, the nucleus raphe magnus, the marginal layers and substantia gelatinosa of the spinal trigeminal nucleus, and the dorsal horn of the spinal cord. Lesion experiments suggest that Met-enkephalin neurons in the dorsal horn and possibly in the spinal trigeminal nucleus are interneurons or propriospinal neurons with nerve terminals in the laminae I and II of the cord and in the superficial layers of the spinal trigeminal nucleus, respectively. These areas are also very rich in substance P-positive nerve terminals, mainly representing central branches of primary afferent neurons. The present immunohistochemical-anatomical findings support the hypothesis that stimulation-produced analgesia is related to activation of spinal and spinal trigeminal enkephalin interneurons forming axo-axonic synapses with (substance P?) pain afferents in the superficial laminae of the dorsal horn and the spinal trigeminal nucleus. These interneurons may be activated by sensory fibers and by descending fibers from medullary stimulation sites. Transmitter substances in these descending fibers may be 5-hydroxytryptamine and substance P.

Analgesia↗
PubMed1977

Occurrence of somatostatin-like immunoreactivity in some peripheral sympathetic noradrenergic neurons.

By means of the indirect immunofluorescence technique of Coons and collaborators, somatostatin-like immunoreactivity has been demonstrated in principal ganglion cells of some sympathetic ganglia. The noradrenergic nature of these cells was established by "staining" of the same or consecutive sections with antiserum to dopamine beta-hydroxylase [dopamine beta-monooxygenase; 3,4-dihydroxyphenylethylamine, ascorbate:oxygen oxidoreductase (beta-hydroxylating), EC 1.14.17.1], the enzyme converting dopamine to noradrenaline (norepinephrine). In guinea pigs the somatostatin immunoreactive material was found in almost two-thirds of all principal ganglion cells of the coeliac-superior mesenteric ganglion complex (anterior inferior part) and of the inferior mesenteric ganglion, but only in a few cells of the superior cervical ganglion. It appeared to be localized close to the Golgi complex. The present findings may represent a concomitant storage of a biogenic amine and a small peptide in a neuron. Because both noradrenaline and somatostatin may fulfill a role as a neurotransmitter or modulator, the sympathetic neurons described in this study may represent an example of mammalian nerve cells not conforming to Dale's hypothesis, i.e., the one neuronone transmitter concept.

Journal Article↗
PubMed1976

Immunohistochemical studies using antibodies to leucine-enkephalin: initial observations on the nervous system of the rat.

Enkephalins are peptides which have pharmacological properties similar to those of morphine. Guinea pigs were immunized with a leucine-enkephalin/thyroglobulin conjugate. Immunofluorescence histochemistry with antiserum revealed a widely distributed system of axons and their terminals in the nervous system of the rat. Prominent networks of enkephalin-like immunoreactivity were found in some brainstem nuclei and in portions of the limbic forebrain. The myenteric plexus in the gastrointestinal tract also contained fluorescent fibers. The distribution of the positive immunofluorescence parallels the occurrence of enkephalin as revealed by biochemical techniques. Some areas known to have a high opiate receptor density were also shown to contain striking networks of enkephalin-like immunoreactivity. Such findings provide morphological support for the hypothesis that enkephalins are contained in nerve terminals close to opiate receptors.

Animals↗