Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tissue from the digitiform rectal gland of the spiny dogfish, Squalus acanthias, was fixed briefly by formaldehyde perfusion and studied for the specificity and localization of p-nitrophenyl phosphatase (NPP'ase) activity. The enzymatic activity was K+-dependent (56%) and ouabain-sensitive (67%-inhibition). The electron-dense reaction product (SrPO4) of the cytochemical reaction (Ernst, 1972b) was localized along the inner surfaces of the basolateral membranes of the secretory cells. It was absent from mitochondria nuclei, vesicles, and other organelles. The luminal surface of the secretory cells was slightly reactive. On the basis of (1) this pattern of localization for the sodium transport system, (2) the presence of extensive intercellular labyrinthine channels (Bulger, 1963) that would facilitate "standing gradients" (Diamond and Bossert, 1968), and (3) the specific distribution of the energy-providing mitochondria, we conclude that the concentration and electrochemical gradients recorded from the secreting gland (Hayslett et al., 1974) are maintained across the domains of the basolateral surfaces of the secretory cells.
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PMID:Localization of ouabain-sensitive, potassium-dependent nitrophenyl phosphatase in the rectal gland of the spiny dogfish, Squalus acanthias. 18 44

Well-characterized antisera to porcine beta-endorphin were used to localize immunoreactive sites in cryostat sections of formaldehyde-fixed rat brain by indirect immunohistochemistry. Specificity was established by absorption of immune sera with synthetic peptide fragments. Specific immunoreactivity was localized to neuronal perikarya in the basal tuberal hypothalamus, and to varicose nerve fibers which were distributed to midline nuclear areas throughout the diencephalon and anterior pons. These patterns of reactivity were unaffected by preabsorption of the immune sera with millimolar concentrations of Met5- or Leu5-enkephalin or alpha-endorphin. The beta-endorphin immunoreactive structures were morphologically separate from those cells and fibers reported to react with antisera to the enkephalins. One anti-beta-endorphin serum gave additional immunoreactivity with myelinated axons in limbic cortical zones; when absorbed with purified rat myelin basic protein, only the specific patterns of immunoreactivity remained. Thus, discrete beta-endorphin-containing neuronal circuits exist in rat brain and are anatomically distinguishable from enkephalin-containing nerve cell and fiber pathways.
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PMID:Neurons containing beta-endorphin in rat brain exist separately from those containing enkephalin: immunocytochemical studies. 34 68

The involvement of the beta-endorphin (B-EP) system during acute prolonged (tonic) pain was investigated by biochemical and behavioral approaches in freely-moving rats after subcutaneous injection of a small amount of a dilute formaldehyde solution (0.08 ml, 5%) in a forepaw. Beta-endorphin-like immunoreactivity levels were increased over the respective control groups in rats killed 30, 60 and 120 min after injection in discrete regions of the rat brain, namely ventro-medial hypothalamus, ventro-basal thalamus and periaqueductal gray matter, and at 30 and 60 min in postero-medial thalamus. In a separate group of experiments a small amount of anti-B-EP or normal rabbit serum was injected in the lateral ventricle; 6 h later rats received formalin injection as in previous groups and their behavior was scored over the following 2 h. A significant hyperalgesia (as expressed by an increase in the amount of time rats spent licking or chewing the injected paw) was observed 10-50 min and 70-80 min after formalin in the anti-B-EP icv-injected group. Other behavioral parameters such as general motor activity, grooming and limb flexion were not different in the two groups, nor was animal behavior prior to formalin injection. Altogether these data suggest that the central beta-endorphin system is triggered by prolonged noxious stimulation in freely-moving animals, and in turn plays a physiological role in the modulation of the reaction to, or perception of, tonic pain.
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PMID:Central beta-endorphin system involvement in the reaction to acute tonic pain. 202 97

The effects of somatostatin, cyclo(D-Trp-Lys-Thr-Phe-Pro-Phe) acetate, a somatostatin analog, neurotensin, and met-enkephalin were studied in the rabbit eye by measuring the intraocular pressure (IOP), aqueous humor protein concentration, ocular blood flow and the pupil diameter. Somatostatin or the analog injected intracamerally (10 micrograms/eye) and infused intra-arterially (0.6-4 micrograms/min) had no significant effect on the parameters studied in normal eyes. However, somatostatin and, particularly, the analog attenuated the miotic response to a standard nociceptive stimulus consisting of topical application of 1% neutral formaldehyde. The other component parts of the irritative response were not attenuated. Intracameral injection of 1-2 micrograms neurotensin caused vasodilation in the anterior segment of the eye, a slight increase in aqueous humor protein concentration, and some decrease in IOP. Intracameral injection of 1-50 micrograms met-enkephalin had no effect on the blood-aqueous barrier, IOP or the pupil diameter. Neither did this dose of met-enkephalin attenuate the miotic response to exogenous substance P. It seems likely that somatostatin and the somatostatin analog attenuate the miotic response to nociceptive stimuli by preventing the release of a substance, presumably substance P, from sensory nerves.
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PMID:Effects of somatostatin, a somatostatin analog, neurotensin and met-enkephalin in the eye with special reference to the irritative response. 290 80

Using adjacent section autoradiography-immunocytochemistry, the distribution of [3H]naloxone binding sites was studied in relation to neuronal systems containing [Leu]enkephalin, dynorphin A, or beta-endorphin immunoreactivity in rat brain. Brain sections from formaldehyde-perfused rats show robust specific binding of [3H]naloxone, the pharmacological (mu-like) properties of which appear unaltered. In contrast, specific binding of the delta ligand [3H]D-Ala2,D-Leu5-enkephalin was virtually totally eliminated as a result of formaldehyde perfusion. Using adjacent section analysis, we have noted associations between [3H]naloxone binding sites and one, two, or all three opioid systems in different brain regions; however, in some areas, no apparent relationship could be observed. Within regions, the relationship was complex; for example, in caudate-putamen, patches of opioid receptors did not correspond to the distribution of enkephalin immunoreactivity, but there was a correspondence between subcallosal streaks of binding sites and enkephalin. The complexity of the association between [3H]naloxone binding sites and the multiple opioid systems, and previous reports of colocalization of mu and kappa receptors in rat brain, are inconsistent with a simple-one-to-one relationship between a given opioid precursor and opioid receptor subtype. Instead, since differential processing of the three precursors gives rise to peptides of varying receptor subtype potencies and selectivities, the multiple peptide-receptor relationships may point to a key role of post-translational processing in determining the physiological consequences of opioid neurotransmission.
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PMID:Combined autoradiographic-immunocytochemical analysis of opioid receptors and opioid peptide neuronal systems in brain. 299 43

Reserpine has a stimulatory effect on the pars intermedia of the rat pituitary, probably mediated by its action on regulatory catecholaminergic nerves. The effect of single intraperitoneal injections of 0.1-20 mg/kg b.w. of reserpine was studied in adult male rats. Reserpine at a dose of 2 mg/kg b.w. induced degranulation, orientation of the secretory granules along the cell membrane and loss of formaldehyde-chloral-induced fluorescence, accompanied by an activation of the granular endoplasmic reticulum and the Golgi apparatus. With higher doses progressive degranulation and loss of fluorescence were observed. The effect was, however, heterogeneous, and with all doses cells displaying normal ultrastructure and normal fluorescence were regularly present. To study the release of granular products (containing a different components of the pro-opiomelanocortin chain) from individual cells, formaldehyde-chloral induced fluorescence and alpha-MSH- and beta-endorphin immunoreactivies were demonstrated in consecutive sections from pituitaries of rats given 8 mg/kg body weight of reserpine 24 h before sacrifice. The results indicate coordinated release of these granular products at the cellular level after reserpine treatment.
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PMID:The effect of reserpine on the pars intermedia of the rat pituitary. An electron-microscopic, fluorescence-histochemical and immunohistochemical study. 316 19

Acrolein was examined as an alternative fixative to formaldehyde for immunocytochemical localization of neuropeptides in the rat brain. A brief (5 min) vascular perfusion with a 5% acrolein solution allowed the identification of thyrotropin-releasing hormone (TRH), vasoactive intestinal peptide (VIP), somatostatin (SRIF), neurotensin (NT), methionine enkephalin (Menk), adrenocorticotropic hormone (ACTH), tyrosine hydroxylase (TH), and luteinizing hormone-releasing hormone (LHRH) in fibers and perikarya within the central nervous system of the rat using the peroxidase-antiperoxidase (PAP) technique. Acrolein appears to be particularly valuable for immunocytochemistry, as it 1) stabilizes heterogeneous peptides and proteins rapidly and effectively, 2) retains antigenicity, and 3) preserves morphological detail.
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PMID:Acrolein: a fixative for immunocytochemical localization of peptides in the central nervous system. 618 5

Considerable evidence has demonstrated an interrelationship between the enkephalinergic and dopaminergic systems in both the mammalian and invertebrate nervous systems. We have described recently the presence of two classes of high affinity opiate binding sites in the nervous tissue of the marine mollusc Mytilus edulis. In order to examine the physiological role of these high affinity opiate sites, M. edulis pedal ganglia (Pg) were treated with the selective neurotoxin 6-hydroxydopamine (1 micrograms/animal, applied topically to the intact Pg); animals were sacrificed 5 days after treatment. The dopamine content of the Pg from lesioned animals was reduced to 33% relative to that of Pg from control animals. Neither serotonin nor norepinephrine levels were reduced. Fluorescent micrographs of formaldehyde-treated Pg from both lesioned and control animals revealed that the neurotoxic substance accumulates in the synaptically rich neuropil and not in the cortex of the Pg. Thus, the partial reduction in dopamine levels may reflect nearly total loss of dopamine in terminals with essentially no change in the nerve cell bodies. High affinity binding of the potent opioid peptide 125I-labeled FK 33-824 (2 nM) was reduced by 81% and low affinity binding (10 nM peptide) by 43% in Pg from lesioned animals relative to that in control tissue. In addition, D-Ala2-Met5-enkephalin, beta-endorphin and etorphine failed to change dopamine levels in lesioned animals. Together, these results suggest that the high affinity opiate binding sites that mediate alteration in dopamine levels are on dopaminergic presynaptic terminals.
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PMID:Evidence for the presynaptic localization of a high affinity opiate binding site on dopamine neurons in the pedal ganglia of Mytilus edulis (Bivalvia). 628 36

Tissue from the pars intermedia of the pituitary from new-born and adult rats was maintained in tissue culture for periods up to 14 days. Both new-born and adult rat pars intermedia cells showed active production of secretory granules during tissue culture, and also showed formaldehyde-chloral induced fluorescence. Immunohistochemically, beta-endorphin could be demonstrated in cultured pars intermedia cells. In contrast to the appearance of the pars intermedia cells in vivo, the granules in the cultured cells were most often seen along the cell membrane, and the cytoplasm was often dominated by clear vacuoles slightly larger than the granules. No exocytotic figures were observed in the cultured cells. The mechanism of hormonal release from the organ, if release does occur, thus remains obscure. In conclusion, cultured cells from the rat pituitary pars intermedia continue their production of hormonal granules in tissue culture, and thus form a valuable tool for further investigations on the complex regulation of hormonal secretion form the organ.
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PMID:Synthesis and storage of hormonal granules in cultured cells of the rat pituitary pars intermedia. 629 1

The histological distribution of met-enkephalin-like immunoreactivity was studied in the forebrain (particularly the striatum) and the spinal cord of the rat using the indirect peroxidase-labelled antibody method. In most experiments, vibratome sections of formaldehyde-fixed tissues and purified antibodies were used. The search for optimal conditions for the immunohistochemical reaction lead us to establish that met-enkephalin-containing perikarya of both untreated and colchicinized animals were better demonstrated when tissue were pre-treated with diluted hydrogen peroxide only. The additional treatment of these sections with Triton X-100 (or some other detergents) resulted in the near disappearance of the perikaryal immunoreactivity; on the contrary, numerous met-enkephalin containing nerve fibres and varicosities were then demonstrated in the same region. Using only the hydrogen peroxide treatment, we found numerous met-enkephalin-containing perikarya in the medial and ventral regions of the neostriatum. This distribution was prolonged caudally by the existence of a prominent group of stained somata in the ventral putamen-central nucleus of the amygdala. When intraventricular injections of colchicine were used, positive perikarya were more numerous within the striatum (the globus pallidus excepted) but their distribution was largely the same as in non injected animals. However, some new groups of somata were stained in this case in the forebrain (in the lateral septum, the olfactory tubercle and the hypothalamus particularly). In control animals only few met-enkephalin-containing perikarya were observed in the dorsal horn of the spinal cord when H2O2 pretreatment was used alone and they were numerous only when intraspinal injections of colchicine were performed. Met-enkephalin-containing fibres and varicosities, which were scattered in the whole neostriatum in the conditions used above, became very numerous when the tissue sections were incubated in the presence of Triton X-100. Their density increased markedly from the latero-dorsal to the medio-ventral regions but, in addition, an organization under the form of islands of stronger immunoreactivity was also evidenced. These islands were more numerous ventrally in the anterior neostriatum and in the central region of the "putamen." The dense plexus of immunoreactive nerve fibers forming "tube-like structures" which was always observed in the paleostriatum and in the cranial medial forebrain bundle (islands of Calleja) appeared more diffuse when detergents were used.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Different localizations of Met-enkephalin-like immunoreactivity in rat forebrain and spinal cord using hydrogen peroxide and Triton X-100. Light microscopic study. 636 51


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