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Biomedical subjects

L Terenius

Publications and source records attributed to L Terenius.

At least 163 records · Page 9Linked to original sources

Increased CSF opioid activity in sleep apnea syndrome. Regression after successful treatment.

The etiology of the SAS is unknown. To test whether endogenous opioids could be pathologically active in SAS, markers of opioid systems were measured in the CSF of 15 patients with SAS and in control subjects. Measured by receptor assay, the concentration of so-called fraction 1 opioid was higher in patients with SAS (3.0 +/- 1.5 pmol/ml; mean +/- SD) than in control subjects (1.1 +/- 0.5 pmol/ml) (p less than 0.01), whereas that of fraction 2 opioid was similar in the two groups. Beta-endorphin-like activity, measured by radioimmunoassay, was somewhat lower in patients with SAS (14.0 +/- 2.8 pmol/ml) than in control subjects (21.8 +/- 7.6 pmol/ml) (p less than 0.05). Six months after surgical treatment of the soft palate, new measurements were made in eight patients. Fraction 2 endorphin and beta-endorphin showed no consistent changes. A decrease in the level of fraction 1 from 4.1 +/- 1.5 pmol/ml to 2.3 +/- 1.0 pmol/ml (p less than 0.02) was noted in those six patients showing a successful clinical course. The data support the hypothesis that in SAS the opioid activity is increased.

Adult↗

Modulation of pain in fibromyalgia (fibrositis syndrome): cerebrospinal fluid (CSF) investigation of pain related neuropeptides with special reference to calcitonin gene related peptide (CGRP).

The cerebrospinal fluid (CSF) levels of calcitonin gene related peptide (CGRP) were 0.94 +/- 0.06 fmol/ml (mean +/- SEM), of substance P, 35.1 +/- 3.2 fmol/ml and of substance P (1-7), 10.8 +/- 1.2 fmol/ml, as measured by radioimmunoassay in 26 female patients with fibromyalgia. No correlation was found between the levels of CGRP and the substance P and substance P (1-7) levels (r = 0.316, p = 0.14). Our results show that the anatomical coexistence of pain related neuropeptides in neurons is not necessarily reflected by the levels of these peptides measured in the CSF. The presence of CGRP in the CSF could be important since it can enhance the nociceptive activity of tachykinins. This may be of importance in the pathogenesis of pain in fibromyalgia.

Calcitonin Gene-Related Peptide↗

Multiple forms of pancreatic polypeptide-related compounds in the lamprey CNS: partial characterization and immunohistochemical localization in the brain stem and spinal cord.

Although neuropeptide Y (NPY) is established as a transmitter in many regions of the nervous system, the role of other peptides of the pancreatic polypeptide (PP) family in the CNS is obscure. This study provides evidence that PP-like peptides in the "primitive" CNS of a cyclostome are composed of different molecular forms, which are stored in separate neuronal populations with apparently different functions. PP-like material was detected in extracts of brain and spinal cord from Lampetra fluviatilis by radioimmunoassay (RIA) using an antiserum to the C-terminal hexapeptide of mammalian PP. The PP-immunoreactive material consisted of several molecular forms, as shown by its complex elution profile on high-performance liquid chromatography (HPLC). The cellular distribution of PP-like immunoreactivity was studied with indirect immunofluorescence histochemistry using antisera toward porcine peptide YY (PYY), porcine neuropeptide Y (NPY), and bovine (BPP), rat (RPP), and avian (APP) pancreatic polypeptide. Adjacent sections from the brain stem and spinal cord of L. fluviatilis and Ichthyomyzon unicuspis, incubated with the different antisera, displayed 2 main patterns of PP immunoreactivity. The PYY and RPP antisera labeled groups of neurons and fibers in the rhombencephalic and mesencephalic reticular formation. One of the PYY/RPP-ir cell groups, located in the anterior rhombencephalic reticular nucleus, had a projection to the dorsolateral spinal cord. Fibers of this reticulospinal system were in close apposition to dendrites of intracellularly stained spinal motoneurons and sensory relay interneurons, indicating that they may receive PPergic input. In contrast, antisera to NPY and APP labeled local neurons systems in the spinal dorsal horn, in the lateral parts of the brain stem, including the rhombencephalic alar plate, and in the retina. The BPP antiserum recognized the NPY/APP as well as the PYY/RPP immunoreactive neuron systems, further supporting that they both contain PP-like peptides.

Animals↗

Prolonged exposure of human neuroblastoma SH-SY5Y cell line to morphine and oxotremorine modulates signal transduction in adenylate cyclase system.

Neurotransmitter receptors coupling to the adenylate cyclase (AC) system were studied in the human neuroblastoma SH-SY5Y cell line. Vasoactive intestinal polypeptide (VIP) caused an up to 40-fold enhancement of the AC activity, while prostaglandin E1 (PGE1) was able to increase the cAMP accumulation 2.5-fold. Stimulation either by VIP or PGE1 was attenuated with either morphine (MOR) or oxotremorine (OXO). Prolonged exposure to MOR and OXO caused a ligand-specific, i.e. homologous desensitization of the opioid and muscarinic acetylcholine receptors, respectively. Preceding desensitization, a supersensitive response of the AC system to VIP was observed. Pretreatment of cells with PT overnight reduced the inhibitory effects of both MOR and OXO. Nevertheless, in cells pretreated with PT and then also with OXO, MOR and OXO inhibited the VIP-induced AC response. Apparently, there are both PT-sensitive and -insensitive pathways to AC inhibition in SH-SY5Y cells.

Adenylyl Cyclases↗

Substance P(1-7) antagonizes substance P-induced aversive behaviour in mice.

Substance P (SP) and its fragments were administered intrathecally into awake mice. SP and C-terminal fragments caused dose-dependent reciprocal hindlimb scratching responses. SP(5-11) was more potent than SP not only in inducing scratching response but also in inducing aversive behaviour including licking and biting. SP(1-7) induced no behavioural reactions. However, when low doses of SP(1-7) (1.0-4.0 pmol) were injected simultaneously with SP or SP(5-11) (0.1 nmol), aversive behaviours induced by SP or SP(5-11) were significantly reduced. These results indicate that SP(1-7) formed endogenously could modulate the actions of SP or SP(5-11) in the spinal cord.

Animals↗

Coupling of receptors in brain membranes by fusion to the adenylate cyclase system of a foreign effector cell.

Receptor-effector coupling in the adenylate cyclase (AC) system was studied using fusion transfer of rat or monkey frontal cortex membranes to Friend erythroleukemia (Fc) cells. The indigenous AC activity of cortex membranes had previously been inactivated with N-ethylmaleimide. In the fusates, the AC activity could be stimulated through beta-adrenoceptors using noradrenaline (NA), or through specific receptors for vasoactive intestinal polypeptide (VIP), or by fluoride which activates the effector components of the AC-system directly, bypassing receptors. There was a critical stoichiometric relationship between the receptor-stimulated cAMP output and the number of recipient cells of the fusion system, i.e. the total AC capacity as measured by fluoride stimulation. In fusates with rat brain membranes, the beta-adrenoceptor coupling increased as the availability of recipient cells increased; on the other hand, the excess of recipient cells did not change the VIP receptor coupling capacity. In fusates with monkey brain membranes, the situation was the opposite: VIP receptor coupling increased as larger amounts of recipient cells were made available, but the beta-adrenoceptor coupling capacity remained unchanged. The differences in coupling capacities were related to differences in receptor binding with higher beta-adrenoceptor density in rat than in monkey frontal cortex membranes, as opposed to higher VIP receptor density in monkey than in rat frontal cortex membranes. Neuropeptide tyrosine (NPY) attenuated both NA- and VIP-induced activation of AC in the fusates; it was equally potent against both agents. In rat brain membrane fusates, the NA-induced AC activity was attenuated in a dose-dependent and apparently non-competitive manner.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗

Role of peptide substrate structure in the selective processing of peptide prohormones at basic amino acid pairs by endoproteases.

Three putative processing enzymes, each with defined action in a prohormone system, a 'pro-ocytocin-neurophysin convertase' from bovine neurohypophysis secretory granules, a 'Leu-enkephalin Arg6 generating enzyme' from human CSF and the endoprotease from the 'S-28 convertase' complex of rat brain cortex, were tested for their ability to hydrolyze peptides deriving from pro-ocytocin, pro-enkephalin B and pro-somatostatin, respectively at pairs of basic amino acids. The observations suggest that structural parameters specified by the peptide region around the dibasic moieties govern recognition by the enzyme and define which peptide bond is hydrolyzed.

Animals↗

Differential modulation of striatal dopamine release by intranigral injection of gamma-aminobutyric acid (GABA), dynorphin A and substance P.

The effects of intranigral injection of gamma-aminobutyric acid (GABA) (dose range: 10.0-300.0 nmol), dynorphin A (0.005-0.5 nmol) and substance P (0.00007-7.0 nmol) on striatal dopamine (DA) release, and dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) formation were studied by microdialysis. It was found that both GABA and dynorphin A produced a dose-dependent decrease in the release of striatal DA following injection into the ipsilateral substantia nigra, the pars reticulata. In contrast, intranigral injection of substance P produced an increase in DA release. However, the dose-response curve for the substance P effect had a biphasic shape. The maximum effect was produced by 0.007 nmol, whereas higher doses (0.07-0.7 nmol) produced less pronounced effects. At the highest dose (7.0 nmol), substance P produced a strong decrease of DA release. Striatal levels of DOPAC and HVA were enhanced by GABA, dynorphin A and substance P. The present results support the concept that substance P, directly or indirectly, provides a positive feed-back regulation for the release of striatal DA, whereas GABA and dynorphin exert a negative feed-back regulation.

3,4-Dihydroxyphenylacetic Acid↗

Enkephalins interact with substance P-induced aversive behaviour in mice.

The effect of the endogenous opioid peptides, methionine-enkephalin (Met-ENK), beta-endorphin (beta-END) and dynorphin-(1-17) (DYN) on the aversive behavior produced by intrathecal (i.t.) administration of substance P (SP) was studied in mice. A low dose of i.t. administered Met-ENK gave a marked reduction of the SP-induced response. In the tail-flick assay, such doses of Met-ENK were ineffective in producing antinociception. At much higher doses, however, Met-ENK obtained antinociceptive activity. In contrast, beta-END and DYN had about the same potency in inhibiting the SP-induced behavioural response and in the tail-flick test, respectively. These results suggest that opioid peptides, particularly enkephalin neurons in the spinal cord influence SP-induced aversive behaviour.

Animals↗

Reduced beta-casein levels in milk samples from patients with postpartum psychosis.

Defatted breast milk from women with postpartum psychosis and from healthy lactating women was analyzed by high-resolution gel permeation chromatography as well as by sodium dodecyl sulfate (SDS) and urea polyacrylamide gel electrophoresis. The gel permeation procedure allowed quantitative analysis of milk proteins (including beta-casein) with minute amounts of defatted milk (10-15 microliter). By electrophoresis, further characterization of the protein pattern, including the beta-casein fraction, was obtained. Milk samples from five control and seven psychotic subjects were analyzed. The concentration of the beta-casein-containing peak was significantly lower in milk samples from the psychotic group by both chromatography and electrophoresis. These lower levels of beta-casein may result from a higher rate of enzymatic degradation generating i.a. peptides with opioid activity, as shown earlier in plasma and CSF of women with postpartum psychosis.

Adult↗

Neuropeptide Y-, tyrosine hydroxylase- and vasoactive intestinal polypeptide-immunoreactive nerves in bone and surrounding tissues.

Nerve fibres immunoreactive to neuropeptide Y (NPY), tyrosine hydroxylase (TH) and vasoactive intestinal polypeptide (VIP) were demonstrated in rat bone and adjacent tissues. The distribution of NPY- and TH-positive fibres differed from that of VIP-positive fibres. NPY- and TH-immunoreactive fibres were almost exclusively found close to or within the blood vessel walls, mostly in the vicinity of the epiphyseal plate, but also in the Volkmann canals. VIP-positive fibres were predominantly present in the epiphysis and periosteum and only occasionally around blood vessels. This study demonstrates that bone and surrounding tissues have a supply of both noradrenergic and peptide-containing nerves. The differential distribution of these nerves may reflect specific roles in the local regulation of bone physiology, such as blood flow, bone formation or resorption.

Animals↗

Expression of the proenkephalin gene in human neuroblastoma cell lines.

Several human tumour cell lines were screened for secretion of proenkephalin-derived peptides with an antiserum directed to its N-terminus, Met-enkephalin-Arg6,Phe7 and for proopiomelanocortin-derived peptides with an antiserum to beta-endorphin. The neuroblastoma SK-N-MC cell line secreted Met-enkephalin-Arg6,Phe7-immunoreactive peptides in relatively high amounts into the culture medium, although processing was not complete and there was no evidence for free Met-enkephalin-Arg6,Phe7. Gene expression was confirmed by the presence of proenkephalin mRNA and proenkephalin-derived polypeptides in extracts of the SK-N-MC cells and also in the neuroblastoma SH-SY5Y cell line. In the latter cells, however, the expression was approximately 3 times lower, there was less processing of proenkephalin and no evidence for secretion.

Adrenal Gland Neoplasms↗

Modulation of endopeptidase activity by calcitonin gene related peptide: a mechanism affecting substance P action?

Peptides with hormonal or neuronal activity are derived by enzymatic processing from pro-hormones, which by themselves are biologically inert. Processing and other enzymatic conversions may occur step-wise, leading to the formation of a cascade of biologically active (or inactive) peptides. The neurokin in substance P is known to be metabolically transformed both by amino- and endopeptidases. More N-terminal substance (1-7) has been found than C-terminal (2-11 to 5-11) fragments in various CNS areas. The substance P (1-7) fragment also shows biological activity e.g., providing analgesia, lowering blood pressure, inhibiting aggressive behavior and (in contrast to substance P) inhibiting grooming behavior. An endopeptidase generating substance P (1-7) and to a lesser extent, substance (1-8), has been isolated and characterized from human cerebrospinal fluid (CSF) and bovine spinal cord, as a metalloenzyme with essential SH-groups. Substance P co-exists with calcitonin gene related peptide (CGRP) in a large population of non-myelinated primary afferent ('pain') fibers. Intrathecal injection of substance P causes behavioral and physiological responses which are potentiated and prolonged by CGRP. It was found that CGRP competes with substance P for the endopeptidase. It is suggested that the main action of CGRP in the spinal cord is to inhibit substance P degradation.

Amino Acid Sequence↗

Substance P in CSF of patients with chronic pain syndromes.

Immunoreactive substance P was determined in lumbar CSF of 35 healthy volunteers and 60 patients with chronic pain syndromes of at least 6 months duration. No significant relationships were found between substance P levels and age, sex or body height. Substance P levels were lower in chronic pain patients, with either neurogenic (n = 23) or idiopathic pain (n = 37) syndromes, than in the healthy volunteers. Substance P levels were especially low in patients with neurogenic pain with lesions involving the extremities and in those with polyneuropathy, while patients with central pain or pain of the head or face had higher values. Substance P levels were related to depressive symptomatology as determined by means of visual analogue scales and to stable personality traits as determined by means of the Karolinska Scales of Personality (KSP). The most consistent (and inverse) relationship was found between substance P levels and the symptom 'inner tension' and between substance P levels and the personality trait 'psychic anxiety.'

Adult↗

Locus coeruleus neurons in the rat containing neuropeptide Y, tyrosine hydroxylase or galanin and their efferent projections to the spinal cord, cerebral cortex and hypothalamus.

The efferent projections of locus coeruleus neurons which contain neuropeptide Y-, tyrosine hydroxylase- or galanin-like immunoreactivity were investigated using the indirect immunofluorescence technique combined with the retrograde transport of the fluorescent substance Fast Blue. Four groups of rats received injections of Fast Blue: (1) bilaterally into the mid-thoracic spinal cord (T6-T7); (2) unilaterally into the low cervical spinal cord (C4-C5); (3) unilaterally into the paraventricular, periventricular and dorsomedial hypothalamic nuclei; and (4) unilaterally into five sites in the cerebral cortex (frontal, cingulate and striate cortex). Efferent projections to the spinal cord, hypothalamus and cerebral cortex from neuropeptide Y-, tyrosine hydroxylase- and galanin-containing locus coeruleus cells were observed. A higher percentage of the peptidergic locus coeruleus neurons projected to the hypothalamus than to the spinal cord or cerebral cortex. The distribution and morphology of the neuropeptide Y- and galanin-containing neurons in the locus coeruleus were also investigated. Neuropeptide Y-like immunoreactivity and galanin-like immunoreactivity were found in small, medium and large multipolar neurons, as well as in fusiform locus coeruleus cells. The neuropeptide Y- and galanin-immunoreactive neurons were found throughout the locus coeruleus. In the caudal locus coeruleus, they were primarily located in the dorsal portion. Neuropeptide Y-like immunoreactivity and galanin-like immunoreactivity were only seen in a few tyrosine hydroxylase-positive neurons of the subcoeruleus group. The data show that the peptide-containing locus coeruleus neurons have efferent projections to the spinal cord, hypothalamus and cerebral cortex. The locus coeruleus may be divided into functional subdivisions dependent on the region of the locus coeruleus, the neurotransmitter/neuropeptide(s) contained within the neurons and their efferent projections.

Animals↗

Expression of eight neuropeptides in intraocular spinal cord grafts: organotypical and disturbed patterns as evidenced by immunohistochemistry.

The present study examines the distribution of several neuropeptides, as revealed by immunohistochemistry in the isolated cord. Fetal rat spinal cord was grafted to the anterior chamber of the adult Sprague-Dawley albino rats. After intraocular maturation for 2-3 months, the amount and distribution of somatostatin, neuropeptide Y, substance P, enkephalin, vasoactive intestinal peptide, peptide histidine-isoleucine, calcitonin gene-related peptide and cholecystokinin immunoreactive terminals and cell bodies were analysed using indirect fluorescence immunohistochemistry. The visualization of immunoreactive cell bodies in the grafts was enhanced using a novel intraocular colchicine treatment. In the graft a rich network of somatostatin-positive terminals was found with a high density in well-demarcated areas reminiscent of substantia gelatinosa of the dorsal horn of normal spinal cord. A large number of small- to medium-sized somatostatin neurons was found throughout the grafts without colchicine treatment. This is in contrast to normal spinal cord, where positive neurons were difficult to visualize without colchicine and were mainly confined to the dorsal horn. Neuropeptide Y had a distribution in the grafts similar to that of somatostatin and neuropeptide Y cells were found throughout the grafts without colchicine treatment. In normal spinal cord, neuropeptide Y-positive fibers were found mainly in substantia gelatinosa with a sparse network in the ventral horn. Enkephalin-positive fibers were found throughout the grafts. The distribution of fibers resembled that of somatostatin and neuropeptide Y with distinct zones of high fiber density in well-demarcated areas, whereas the density of nerve fibers in the rest of the graft neuropil was moderate to low. The distribution of substance P was similar to that of enkephalin. After colchicine treatment, both enkephalin- and substance P-positive cell bodies were visualized. In the intact spinal cord both peptides were seen in the entire gray matter with the highest concentrations in the superficial laminae of the dorsal horn. Antisera against calcitonin gene related-peptide, revealed a sparse terminal network and many large cells, which might represent motoneurons. A sparse network of varicose cholecystokinin-immunoreactive fibers was found evenly distributed in the grafts. In normal spinal cord a dense cholecystokinin-positive network of primary sensory afferent origin was found in the dorsal horn. In the grafts cholecystokinin cell bodies were seen after colchicine treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Neuropeptide tyrosine in the rat adrenal gland--immunohistochemical and in situ hybridization studies.

The adrenal gland of the rat was analysed with immunohistochemistry and antisera to neuropeptide tyrosine, to the catecholamine-synthesizing enzymes tyrosine hydroxylase, phenyl-ethanolamine-N-methyltransferase, and to acetylcholinesterase and with in situ hybridization using a nick-translated 280 base pair deoxyribonucleic acid probe coding for exon 2 of the rat neuropeptide tyrosine gene. Neuropeptide tyrosine-like immunoreactivity was observed in three structures: chromaffin cells, medullary ganglion cells and nerve fibers. The chromaffin cells were of both the noradrenaline- and adrenaline-type. The ganglion cells did not seem to contain any catecholamine-synthesizing enzymes but exhibited a strong immunoreaction for acetylcholinesterase. They were thus in all probability cholinergic neurons. In situ hybridization using the nick-translated deoxyribonucleic acid probe to rat neuropeptide tyrosine messenger ribonucleic acid revealed a very high-grain density over the ganglion cells, a moderate density over the chromaffin cells and a low background over cortex, in agreement with the immuno-histochemical demonstration of neuropeptide tyrosine-like immunoreactivity both in chromaffin and ganglion cells. The intense neuropeptide tyrosine-like immunoreactivity and low content of neuropeptide tyrosine messenger ribonucleic acid suggest that the chromaffin cells have fairly large peptide stores but that the peptide turnover is low. In contrast, the ganglion cell bodies seem to contain low amounts of neuropeptide tyrosine-like immunoreactivity but exhibit a high neuropeptide tyrosine synthesis rate. Preliminary studies with the amine-depleting drug reserpine revealed an increase in messenger ribonucleic acid both in ganglion cells and medullary cells. In the chromaffin cells the highest activity was seen 3 and 4 days after injection, and the levels were down to normal after 8 days. The present findings demonstrate neuropeptide tyrosine synthesis and storage in two cell populations in the adrenal medulla. In situ hybridization with its cellular resolution can provide information on possible differential effects of drugs and experimental procedures on these two neuropeptide tyrosine stores.

Acetylcholinesterase↗