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Biomedical subjects

L Terenius

Publications and source records attributed to L Terenius.

At least 325 records · Page 18Linked to original sources
PubMed1980

Cerebrospinal fluid endorphins in schizophrenia.

Opioid-receptor-active material, endorphins, has been measured in cerebrospinal fluid samples obtained from schizophrenics. A chromatographic procedure isolated the Fraction I endorphin which was quantitated in a receptorassay. At least two cerebrospinal fluid samples were obtained from each patient, at Day 0 with no medication and at Days 30 and 60 after medication with fluphenazine under standardized conditions. Three series of patients were included: acute schizophrenics (= 11); re-entry schizophrenics (n = 7) who have previously been treated with neuroleptics but were readmitted to hospital usually as a consequence of stopped medication, and chronic schizophrenics (n = 9) who had been without neuroleptics for at least 2 weeks prior to Day 0. At Day 0, 6/9 acute cases, 4/6 of re-entry and 2/9 chronic cases had endorphin levels above the range of healthy volunteers. The levels in chronic cases were significantly lower than those in acute cases. Treatment with neuroleptics significantly lowered the endorphin levels in acute cases. These results confirm and extend previous observations.

Adult↗
PubMed1980

Opiate receptors: problems of definition and characterization.

Receptor binding analysis has a great potential in identifying the site of action of a particular drug and in structure-activity studies. However, since no functional response is measured, an intrinsic difficulty to overcome is in establishing the functional significance of drug binding data. The multiplicity of receptors and subreceptors has a correspondence in a multiplicity of binding sites. It is not trivial which radioactive ligand is used to characterize the sites, and it is suggested that several radioligands with different properties (agonists, antagonists etc.) are studied. Methods are described here that allow for the analysis of ligand selectivity between several sites and their relative regional distribution. When enough data have been accumulated it may be possible to attribute a functional correlate to the binding data.

Animals↗
PubMed1980

Evidence for vagal enkephalinergic neural control of the feline pylorus and stomach.

The atropine- and guanethidine-resistant contraction of the cat pyloric sphincter induced by efferent stimulation of the cervical vagi, was studied with a new method for measuring transpyloric flow. The pyloric contraction was blocked in a dose-dependent manner by the opiate antagonist naloxone infused intraarterially to the pyloric region. Local intraarterial injection of morphine or enkephalinamide elicited a pyloric and gastric contraction. Leu- and met-enkephalin intraarterially elicited a pyloric contraction and a gastric relaxation. These effects could be prevented or reversed by naloxone. Immunohistochemical studies revealed a particularly rich enkephalinergic innervation of the pylorus with dense networks of varicose nerve fibers with enkephalin-like immunoreactivity both in the circular smooth muscle layer and in the myenteric plexus. Furthermore, many cell bodies of the myenteric plexus with enkephalin-like material were demonstrated. The corpus-antrum was sparsely innervated by enkephalin-like nerves to the circular muscle layer and only few immunoreactive cell bodies were observed in the myenteric plexus. These results together suggest a vagal control of the feline pylorus and stomach mediated via enkephalinergic neurons.

Animals↗
PubMed1979

Enkephalin levels decrease in rat striatum during morphine abstinence.

Male Sprague-Dawley rats were treated with morphine for 11 days. Saline-injected animals served as controls. The striatal enkephalin levels were measured with a radioimmunoassay 2, 24 and 48 h after withdrawal. There was no change 2 h after the last morphine injection, but a marked reduction after 24 h and a slight decrease after 48 h. No decrease in enkephalin levels was found 12 and 24 h after a single dose of 20 mg/kg morphine.

Animals↗
PubMed1979

Ibotenic acid-induced neuronal degeneration: a morphological and neurochemical study.

Possible neurotoxic actions of intracerebral injections of ibotenic acid, a conformationally restricted analogue of glutamic acid, have been evaluated in rat brain and compared with those of kainic acid. Light microscopical analysis revealed that ibotenic acid produced a marked disappearance of nerve cells in all areas studied, namely striatum, the hippocampal formation, substantia nigra and piriform cortex. Lesions in areas distant to the injection site were not seen. Axons of passage and nerve terminals of extrinsic origin did not seem to be damaged, since, e.g., no apparent degeneration of the dopaminergic terminals in the neostriatum was observed except for a small area surrounding the cannula. In the neostriatum, enkephalin immunoreactive neuronal cell bodies as well as nerve terminals disappeared after injection of ibotenic acid into this nucleus. After injection into the substantia nigra tyrosine hydroxylase immunoreactive cell bodies in the zona compacta disappeared, whereas no certain effect could be seen on the enkephalin immunoreactive nerve fibers. In vitro experiments, conducted with striatal synaptosomal and membrane preparations, showed that ibotenic acid differed from kainic acid by being devoid of a significant inhibitory effect on high affinity glutamate uptake and by having a low affinity for 3H-kainic acid binding sites. Furthermore, ibotenic acid did not interfere with the binding of a number of radioligands for other transmitter receptors. As compared to kainic acid, ibotenic acid has the advantage of being less toxic to the animals and of producing more discrete lesions, possibly due to faster metabolism and/or other fundamental biochemical differences. Because of these special features, ibotenic acid seems to represent a valuable new tool in the morphological and functional analysis of central neuronal systems.

Animals↗
PubMed1979

Personality traits in chronic pain patients related to endorphin levels in cerebrospinal fluid.

Interindividual differences in endorphin levels may relate to widespread changes in adaptive processes, and endorphin levels may thus be related to personality traits. In 40 patients with chronic pain syndromes of both psychogenic and organic origin, endorphin levels in cerebrospinal fluid (CSF) were determined, and the patients completed Eysenck's Personality Inventory (EPI) and the Cesarek Marke Personality Scheme. Twenty-seven of the patients also completed the Zuckerman Sensation Seeking Scale (SSS). As a comparison group 30 healthy volunteers completed the personality inventories. The chronic pain patients were characterized by guilt feelings, need for order, low need for autonomy, and low tendency toward sensation seeking. Low levels of endorphins in CSF were found in patients with high scores on all the subscales in the SSS and low scores on the neuroticism subscale in the EPI.

Adult↗
PubMed1979

Enkephalin- and somatostatin-like immunoreactivities in human adrenal medulla and pheochromocytoma.

By using the Coons indirect immunofluorescence technique, enkephalin-like immunoreactivity with a granular localization was observed in human adrenal medullary gland cells and pheochromocytomas. In two of the tumors and in a few adrenal gland cells, a somatostatin-like peptide could also be identified. Catecholamine cell types were visualized on adjacent sections with antisera to the synthesizing enzymes dopamine-beta-hydroxylase [DBH; dopamine beta-monooxygenase; 3,4-dihydroxyphenylethylamine, ascorbate: oxygen oxidoreductase (beta-hydroxylating), EC 1.14.17.1] and phenylethanolamine-N-methyltransferase (PNMT; noradrenalin N-methyltransferase; S-adenosyl-L-methionine:phenylethanolamine N-methyltransferase, EC 2.1.1.28). In the normal adrenal medulla more DBH- than PNMT-immunoreactive gland cells were observed. In the adrenal pheochromocytoma both DBH- and PNMT-positive cells were seen, whereas the two extra-adrenal tumors contained only DBH. These findings correlated well with plasma catecholamine measurements. Finally, enkephalin immunoreactive fibers and somatostatin immunoreactive cells were observed in a sympathetic ganglion extirpated together with one of the tumors.

Adrenal Gland Neoplasms↗
PubMed1979

Endorphins in CSF of chronic pain patients, in relation to augmenting-reducing response in visual averaged evoked response.

In 45 consecutive patients with chronic pain, visual averaged evoked responses (VAER) and the levels of fraction 1 endorphins in CSF were investigated. Patients with an augmenter response in VAER, i.e. the maximum amplitude increases when stimulus intensity is increased, were found to have significantly lower levels of fraction 1 endorphins than patients with a reducer response, i.e. the maximum amplitude in VAER decreases when stimulus intensity is increased. The results indicate that the endorphins function as endogenous antinociceptive factors.

Adult↗
PubMed1979

Substance P-, VIP-, and enkephalin-like immunoreactivity in the human vagus nerve.

The human vagus nerve has been investigated for the presence of substance P (SP), vasoactive intestinal polypeptide (VIP), and enkephalin (ENK) using immunohistochemistry. After 0.5-4 hr of nerve ligation during surgical operations two right thoracic main truncs, two anterior subdiaphragmal trunks, and four anterior nerves of Latarjet were found to contain accumulation of immunoreactive material in nerve fibers above the ligation. Very high numbers of SP-, medium numbers of ENK-, and low number of VIP-immunoreactive fibers were seen. The relative proportions were similar at all levels studied. These data thus indicate the presence and axonal transport of SP-, ENK-, and VIP-like peptides in the human vagus nerve. Our observations in humans correlate well with results obtained from other species. Thus gastrointestinal vagal sensory mechanisms may be mediated by SP (and possibly VIP) and some motor mechanisms by ENK.

Endorphins↗