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Biomedical subjects

L Terenius

Publications and source records attributed to L Terenius.

At least 289 records · Page 16Linked to original sources
PubMed1982

The distribution of polypeptide YY (PYY) - and pancreatic polypeptide (PP) - immunoreactive cells in the domestic fowl.

The distribution of the polypeptide which has an N-terminal tyrosine and a C-terminal tyrosine (PYY) - and pancreatic polypeptide (PP) - immunoreactive cells were investigated in the gut of the domestic fowl. PPY-immunoreactive cells were observed in the duodenum and jejunum. PP-immunoreactive cells were seen in the duodenum, jejunum, ileum and colon. Both PYY- and PP-immunoreactive cells were extended from the basal lamina to the gut lumen i.e. of open type. PYY-immunoreactive cells occurred mainly in the basal and middle portion of the villi. On the other hand, PP-immunoreactive cells were located mostly in the crepts. The occurrence of PYY-immunoreactive cells in the upper part of the small intestine is rather similar to that of amphibians and reptiles, than to that of mammals, where PYY-immunoreactive cells are located in the distal part of the small intestine and in the large intestine.

Animals↗
PubMed1982

Circannual variation in concentrations of endorphins in cerebrospinal fluid.

In a series of 90 patients with chronic pain syndromes of psychogenic and organic etiology, the concentrations of fraction I endorphins in cerebrospinal fluid were investigated. A significant circannual variation in the concentrations of endorphins was found, with the highest concentrations in January-February and the lowest concentrations in July-August. There was no corresponding seasonal variation with regard to age, sex, bodylength, possible etiology of the pain syndrome self-rated pain levels, or experimental pain measures. Circannual difference in the intensity of symptoms in chronic pain syndromes and in affective disorders have been described in the literature. The present results suggest an association between these observations, giving further support for functional importance of endorphins in chronic pain.

Adult↗
PubMed1982

Enkephalin-containing sympathetic preganglionic neurons projecting to the inferior mesenteric ganglion: evidence from combined retrograde tracing and immunohistochemistry.

The origin of fibers containing enkephalin immunoreactivity in the inferior mesenteric ganglion of the guinea-pig was studied by combining retrograde axonal tracing and indirect immunofluorescence techniques. Fast Blue was applied into the inferior mesenteric ganglion. Three days later colchicine was administered into the subarachnoid space in order to increase the peptide content of the spinal cord cell bodies. The drug was injected through a catheter which was inserted into the cisterna magna and moved to the appropriate spinal cord levels. After the colchicine injection the animals were perfused with formalin and the L2-L3 spinal cord segments were dissected. Cryostat sections of the spinal cord were analyzed in a fluorescence microscope and subsequently processed for indirect immunohistochemistry using antiserum against enkephalin. Several sympathetic preganglionic neurons containing both Fast Blue and enkephalin-like immunoreactivity were seem mainly in the intermediolateral cell column of the cord. The observations strongly support the view that at least some of the enkephalin-containing fibers in the inferior mesenteric ganglion originate in the sympathetic preganglionic nuclei of the spinal cord. These findings are discussed in view of recent physiological studies which have shown that enkephalin may have a presynaptic inhibitory action on preganglionic neurons as well as on substance P containing primary afferent neurons in the inferior mesenteric ganglion.

Adrenergic Fibers↗
PubMed1982

Coexistence of somatostatin- and avian pancreatic polypeptide (APP)-like immunoreactivity in some forebrain neurons.

The indirect immunofluorescence technique was used to demonstrate the coexistence of somatostatin together with avian pancreatic polypeptide-like immunoreactivity within certain neurons of the rat forebrain. Numerous neurons containing these peptides were observed in the neocortex, hippocampus, olfactory tubercle, striatum, nucleus accumbens and lateral septum. In studies of serial sections stained alternately for these two peptides, and in restaining experiments, It could be determined that in many neurons in these areas these two peptides coexisted. In other brain areas such as the anterior periventricular hypothalamus, somatostatin cells were never found to contain avian pancreatic polypeptide-like immunoreactivity. Also, within the pancreas these two peptides were never found to coexist in the same cells. The findings represent a further example of the coexistence of more than one neuropeptide within a single neuron.

Animals↗
PubMed1982

Localization of peptide YY (PYY) in gastrointestinal endocrine cells and effects on intestinal blood flow and motility.

In immunohistochemical studies using antisera to peptide YY (PYY), a 36 amino acid polypeptide isolated from porcine duodenum, it was found that PYY-like immunoreactivity occurred mainly in endocrine cells of the gastrointestinal mucosa. PYY-immunoreactive cells were particularly abundant in the distal intestine and have been observed in five species, including man. By radioimmunoassay it was found that, in the rat, the amount of PYY immunoreactivity was about 100-fold higher in the colon than in the duodenum. The chromatographic profiles of PYY immunoreactivity from the rat colon and porcine PYY on a SP-Sephadex ion exchanger were similar. Furthermore, serial dilutions of extracts from the rat colon and porcine PYY had parallel displacement curves in radioimmunoassay. Close intraarterial administration of PYY in cats caused an intestinal vasoconstriction and an inhibition of jejunal and colonic motility. Simultaneously there was a rise in systemic arterial blood pressure. These effects of PYY were also observed after pretreatment with adrenergic blocking agents. It is concluded that PYY is a gastrointestinal peptide that is present mainly in endocrine cells of distal intestine and that has effect on both intestinal motility and the cardiovascular system.

Animals↗
PubMed1982

Organizational principles in the peripheral sympathetic nervous system: subdivision by coexisting peptides (somatostatin-, avian pancreatic polypeptide-, and vasoactive intestinal polypeptide-like immunoreactive materials).

Sympathetic ganglia and some peripheral tissues of adult guinea pig and cat were analyzed by the indirect immunofluorescence technique with antisera to catecholamine-synthesizing enzymes and some peptides. In the guinea pig, noradrenergic neurons could be subdivided into three populations containing respectively (i) somatostatin-like immunoreactive material, (ii) avian pancreatic polypeptide (APP)-like immunoreactive material, and (iii) apparently only noradrenaline (NA; norepinephrine). A fourth population of sympathetic neurons was nonadrenergic and contained vasoactive intestinal polypeptide (VIP)-immunoreactive material. In the cat many noradrenergic neurons with APP and some without this peptide were seen, but no somatostatin-immunoreactive neurons were observed. Also a population of non-adrenergic, presumably cholinergic, neurons containing a VIP-like peptide was observed. These neuron populations seemed to innervate different tissues with some target specificity. For example, in the nasal mucosa of the cat, nerves containing NA/APP-like immunoreactive material (called NA/APP nerves) were found around small arteries and arterioles, whereas venules and sinusoids were surrounded by nerves containing only NA (called NA nerves). Also in the submandibular salivary gland of the cat, the NA/APP nerves surrounded arteries and arterioles, whereas NA nerves were seen in relation to acini and ducts. The sympathetic (cholinergic) VIP-containing neurons innervated blood vessels and exocrine tissue in the cat sweat glands. In the coeliac-superior mesenteric ganglion complex of the guinea pig and cat, a dense network of VIP-immunoreactive fibers was seen preferentially around noradrenergic ganglionic cell bodies lacking APP-immunoreactive material. Thus, adult peripheral sympathetic neurons can be subdivided into several categories on the basis of specific peptides. These subdivisions may innervate specific targets and may receive peptide-specific neuronal inputs.

Animals↗
PubMed1982

Endorphins and the modulation of acute pain.

The endorphins constitute a large family of structurally but not generically related peptides. They act pharmacologically like narcotic analgesics. An intimate connection between endorphin fibers and pain pathways is present, for instance, at the spinal level and at the first synapse of primary afferent pain fibers. These fibers may contain the neuropeptide substance P. In acute pain, naloxone injection causes a significant increase in pain suffering. A patient with high preoperative endorphin levels in the cerebrospinal fluid will require less pethidine for adequate pain relief after major abdominal surgery. Pethidine administration reduces substance P levels in the cerebrospinal fluid. The data suggest that endorphins do not have a protective role in acute pain conditions.

Acupuncture Therapy↗
PubMed1982

An improved foot-shock titration procedure in rats for centrally acting analgesics.

A foot-shock titration method for the measurement of antinociceptive activity in the rat has been developed. A new grid design is described which makes the use of scrambled shocks unnecessary. Thresholds for responses elicited at different levels of integration within the central nervous system are measured: Detection threshold, flexor reflex, coordinated jumping and vocalization. These thresholds were found to be stable over time in saline-treated rats. The two opioid analgesics morphine and d-propoxyphene increased these thresholds, each in a characteristic way. Morphine was more selective in its action and significantly more effective in increasing the vocalization threshold than the threshold for jumping, whereas d-propoxyphene increased both these thresholds to the same extent. Neither drug affected the detection threshold in low to moderate doses. The difference in pharmacodynamic profile is discussed in terms of heterogeneity of opioid receptor-effector mechanisms at different levels of the neuroaxis.

Analgesics↗
PubMed1982

Endorphin levels in opioid-dependent human subjects: a longitudinal study.

Endorphin levels were measured in 51 cerebrospinal fluid samples from 27 opioid-dependent or postdependent subjects. Radioreceptor assay showed the endorphin levels to be higher than those found in normal subjects. These high levels were found even while subjects were on methadone maintenance. The duration of opioid dependence was positively correlated with fraction I values. Both fractions tended to be lower during early withdrawal than late withdrawal. In naltrexone-maintained patients, radioreceptor assay showed FII to be greatly elevated, but electrophoresis and HPLC indicated that the elevations were not due to a peptide. Thus, the possibility of unextracted naltrexone metabolites remains at least a partial explanation for this apparent FII elevation.

Adult↗
PubMed1982

Oestrogens and anti-oestrogens show dissociation between early uterine vascular responses and uterotrophic effects in mice.

The structure-activity relationships of various natural and synthetic oestrogens, anti-oestrogens and some other steroid hormones with respect to early uterine albumin accumulation (EAV) was studied in sprayed mice. The results were compared with the activity of these agents to produce a late anabolic response (LAR). The potency ranking order among the oestrogens with respect to EAV was found to be oestradiol-17 beta, greater than oestriol, greater than meso-hexoestrol, greater than erythro-deoxyhexoestrol, greater than ent-oestradiol-17 beta, greater than (-)methallenestril phenol. Generally the oestrogens were much more potent with respect to EAV than LAR. No correlation was found when the ability to promote EAV and LAR was compared. Among other agents tested for effect on the EAV, progesterone, the synthetic progestogen, DU-41165 and the anti-hormones MER-25 and U-11100A (nafoxidine) showed no effect. However, hydrocortisone diminished EAV, while dihydrotestosterone increased EAV substantially.

Animals↗
PubMed1981

Des-tyrosine1-gamma-endorphin increases the antinociceptive efficacy of morphine in the rat.

Repeated injections of des-tyrosine1-gamma-endorphin (DT gamma E) to rats subjectively increased sensitivity to handling. After 8 days of treatment, the animals were supersensitive to a low dose of morphine in the foot-shock test. Acute treatment with DT gamma E gave no significant increase in morphine sensitivity. The results indicate that DTgammaE given chronically interacts with opioid receptor-effector mechanisms.

Analgesia↗
PubMed1981

d-Propoxyphene acts differently from morphine on opioid receptor-effector mechanisms.

The actions of d-propoxyphene and morphine on opioid receptor mechanisms were compared. In assay measuring receptor binding selectivity in vitro, with dihydromorphine, naloxone and an enkephalin analogue as radioactive ligands, d-propoxyphene differed from morphine in having a higher relative affinity for sites occupied by the peptide. Naloxone was more potent in antagonizing morphine- than d-propoxyphene-induced antinociception in the mouse hot-plate test. In morphine-tolerant mice showing three-fold lower morphine sensitivity the antinociceptive efficacy of d-propoxyphene was unchanged. The results indicate differences in receptor-effector mechanisms between d-propoxyphene and morphine.

Animals↗
PubMed1981

Immunohistochemical studies on the effect of capsaicin on spinal and medullary peptide and monoamine neurons using antisera to substance P, gastrin/CCK, somatostatin, VIP, enkephalin, neurotensin and 5-hydroxytryptamine.

After neonatal treatment of rats with capsaicin, the spinal cord, the spinal trigeminal nucleus and spinal and trigeminal ganglia were analysed with immunohistochemistry using antisera to several peptides and 5-hydroxytryptamine. A marked decrease was observed in substance P-, cholecystokinin-, somatostatin- and VIP-like immunoreactivity present in the central branches of primary sensory neurons in the spinal cord and in substance P- and somatostatin-like immunoreactivity in sensory ganglion cells. No definite depleting effect of capsaicin could be established on 5-hydroxytryptamine and peptides, such as enkephalin and neurotensin, present in centrally originating fibres in the dorsal horn of the spinal cord. The results demonstrate that the effects of capsaicin are not confined to substance P immunoreactive primary sensory neurons. The possibility is discussed that capsaicin effects specifically functioning rather than chemically specific primary sensory neurons.

Animals↗