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Biomedical subjects

E Theodorsson

Publications and source records attributed to E Theodorsson.

At least 73 records · Page 4Linked to original sources

Substance P-associated increase of intra-articular temperature and pain threshold in the arthritic TMJ.

Neuropeptides are considered mediators and modulators of inflammatory joint disease. Substance P (SP) has been proposed as a mediator of pain, and its vasoactive properties are well documented. In this study, the presence of SP-like immunoreactivity in the synovial fluid was correlated to intra-articular temperature (IAT) and pain from the arthritic temporomandibular joint (TMJ) 3 to 5 weeks after one intra-articular injection of glucocorticosteroids. Eighteen TMJs were investigated for IAT and the presence of SP-like immunoreactivity in the synovial fluid in 12 patients with systemic inflammatory joint disease. After arthrocentesis, the aspirates were analyzed for SP-like immunoreactivity by means of competitive radio immunoassay. A visual analogue scale and an algometer determining the pressure pain threshold and tolerance level assessed arthritic pain and hyperalgesia in the TMJ. Our results indicate that SP-like immunoreactivity is associated with IAT and that increased concentrations of joint fluid SP-like immunoreactivity correspond to increased pain threshold and tolerance and a concomitantly decreased visual analogue scale. These findings suggest that SP is implicated in the vascular and nociceptive response of the arthritic joint and that SP, possibly assisted by the antinociceptive effect of local corticosteroids, has a modulatory role in arthritic pain and hyperalgesia.

Adult↗

Effects of histamine on neuropeptide release into the knee joint perfusate and cerebrospinal fluid in rats.

In the present study we examined the effect of histamine injection on neuropeptide release in vivo in rats. Rats were injected with histamine either into the left knee joint or intraperitoneally. Concentrations of substance P (SP)-, neurokinin A (NKA)-, calcitonin gene-related peptide (CGRP)- and neuropeptide Y (NPY)-like immunoreactivity (-LI) were examined in the knee joint perfusates and cerebrospinal fluid at 2, 6 and 24 h following injection, by radioimmunoassay. Results show that intraarticular injection of histamine induced a bilateral release of SP-, NKA- and CGRP-LI in the knee joint perfusates while intraperitoneal injection of histamine induced a release of SP-, NKA- and CGRP-LI into the cerebrospinal fluid. No changes in concentrations of NPY-LI were observed following histamine injection. Results of the present study indicate that histamine selectively stimulates sensory neurons without affecting sympathetic. The increased concentrations of sensory neuropeptide-LI in the cerebrospinal fluid following intraperitoneal administration of histamine indicate a new mechanism by which histamine may exert systemic effects during inflammation and allergy.

Animals↗

Effects of capsaicin in temporomandibular joint arthritis in rats.

Temporomandibular joint (TMJ) arthritis was induced in female Lewis rats by unilateral injection of a suspension of heat-killed Mycobacterium butyricum in paraffin oil into the TMJ. Control rats received paraffin oil by the same route. Arthritic and control rats were pretreated either with capsaicin or denervation of the mandibular branch of the trigeminal nerve. Tissues were collected for neuropeptide extraction and analysed by radioimmunoassay and reverse-phase high-performance liquid chromatography. In all groups, the levels of substance P-(SP), calcitonin gene-related peptide- (CGRP) and neuropeptide Y- (NPY) like immunoreactivity (LI) were higher in the trigeminal ganglia than in the TMJs. In control rats, capsaicin significantly lowered the levels of SP-LI in the trigeminal ganglia and TMJ, but not CGRP-LI and NPY-LI. In the arthritic rats, capsaicin pretreatment significantly lowered the SP-LI and CGRP-LI in the trigeminal ganglia and TMJ, but not the NPY-LI. In the trigeminal ganglia the unilateral denervation significantly lowered SP-LI in control rats, and in arthritic rats SP-LI and CGRP-LI. On the denervated side of the arthritic TMJ, NPY-LI, SP-LI and CGRP- LI were significantly lowered as compared to the arthritic control rats and to the contralateral side. In this rat model, pretreatment with capsaicin and surgical denervation decreased the neuropeptide content in the trigeminal ganglia and the TMJ. The results clearly demonstrate a close interaction between increased neuropeptide release from sensory and sympathetic neurones after induction of arthritis in the rat.

Animals↗

Neuropeptides in the saliva of healthy subjects.

Five neuropeptides: Substance P (SP), Neurokinin A (NKA), Calcitonin Gene-Related Peptide (CGRP), Neuropeptide Y (NPY) and Vasoactive Intestinal Polypeptide (VIP), were measured in the saliva of eight subjects. The saliva was collected using different stimulation techniques: whole resting saliva, whole paraffin stimulated saliva, whole citric acid stimulated saliva and parotid saliva of different secretion rates -0.25 mL/min, 0.50 mL/min and 1.00 mL/min, also stimulated by citric acid. The neuropeptides were analysed by radioimmunoassay. The results showed that the concentration of all neuropeptides decreased significantly, two- to four-fold (CGRP up to 16-fold) in whole saliva, when the salivary secretion rates increased six- to eight-fold due to stimulation. However, the amounts of all neuropeptides released over time into the whole saliva increased two- to five-fold (ten-fold for CGRP) as the volumes of saliva increased due to chewing-stimulation as compared to resting saliva or citric acid stimulated saliva. There was also more CGRP in the resting saliva than in the citric acid stimulated saliva. The concentration of CGRP in the parotid saliva decreased three- to ten-fold when the salivary flow increased, whereas the concentration of NKA increased three- to four-fold and that of NPY almost two-fold under the same conditions. The concentrations of SP and VIP did not change in the different flows of parotid saliva. The release of all neuropeptides in the parotid saliva over time showed significant increases (3-14-fold) when the secretion rates increased except CGRP, which showed no changes at all. We concluded that neuropeptides are continuously released into the saliva. Their amounts increase with stimulation, but they are diluted by the increased volume of saliva, and they are also affected by the mode of stimulation-muscular activity leads to a greater release than citric acid stimulation. As the neuropeptides play an important role in the control of salivary secretory mechanisms, their normal occurrence and release are of fundamental importance for the understanding of the function of the salivary glands.

Adult↗

Intrathecal CGRP(8-37) results in a bilateral increase in hindpaw withdrawal latency in rats with a unilateral thermal injury.

The present study was performed to explore the effects of intrathecal administration of calcitonin gene-related peptide8-37 (CGRP(8-37)) on the hindpaw withdrawal latency (HWL) to pressure in rats with one thermally injured hindpaw. Furthermore, the interaction of CGRP(8-37)and naloxone was studied. Thermal injury was performed by dipping the left paw into 60 degrees C for 20 s. This induced a significant increase in the volume of the left hindpaw (P<0.001) and significant bilateral decreases of the latency of hindpaw withdrawal response to mechanical stimulation (Left: P<0.001; right: P<0.05). Intrathecal administration of 10, 20 and 40 nmol of CGRP(8-37), but not of 1 or 5 nmol, induced a significant bilateral increase in HWLs (P<0.001). The effect of CGRP(8-37) was partly reversed by intrathecal injection of naloxone at a dose of 32 and 64 microg respectively. Using radioimmunoassay, we found a significant bilateral increase in the concentration of CGRP-like immunoreactivity in the perfusate of both hindpaws 24 h after unilateral thermal injury (left: P< 0.001; right: P< 0.05). There was also an increase in the amount of CGRP-like immunoreactivity in the cerebrospinal fluid (P< 0.001), but not in plasma. The results indicate that CGRP plays a role in the transmission of nociceptive information in the spinal cord of thermally injured rats. Furthermore, our findings suggest that opioids can modulate CGRP-related effects in the spinal cord.

Animals↗

Somatostatin in neuroblastoma and ganglioneuroma.

Neuroblastoma, a childhood tumour of the sympathetic nervous system, may in some cases differentiate to a benign ganglioneuroma or regress due to apoptosis. Somatostatin may inhibit neuroblastoma growth and induce apoptosis in vitro and was therefore investigated. Using a radioimmunoassay, we found that all ganglioneuromas contained high somatostatin concentrations (> 16 pmol/g), significantly higher than neuroblastomas (n = 117, median 2.8 pmol/g), healthy adrenals, Wilms' tumours, phaeochromocytomas and other neuroendocrine tumours (P < 0.001). Neuroblastomas contained more somatostatin than control tumours (P < 0.001-0.05). Neuroblastomas amplified for the MYCN oncogene contained less somatostatin than non-amplified tumours (1.2 pmol/g versus 4.0 pmol/g, respectively; P = 0.026). In a clinically unfavourable neuroblastoma subset (age > 12 months, stage 3 or 4) 16 children with high concentrations of somatostatin in primary tumours had a better prognosis than 23 with low somatostatin (46.7% versus 0% survival at 5 years, P < 0.005). Scintigraphy using 111In-pentetreotide identified tumours expressing high-affinity somatostatin receptors in vivo. However, no significant correlation was found between somatostatin receptor expression and peptide content in 15 tumours. Similarly, human SH-SY5Y neuroblastoma xenografts grown in nude rats showed low somatostatin concentrations, but were positive for somatostatin receptor scintigraphy. Treatment of these rats with the somatostatin analogue octreotide seemed to upregulate in vivo receptor expression of somatostatin and vasoactive intestinal peptide more effectively than 13-cis retinoic acid. In conclusion, somatostatin in neuroblastoma is associated with differentiation to benign ganglioneuromas in vivo and favourable outcome in advanced tumours. Furthermore, somatostatin receptor scintigraphy may identify tumours with high-affinity receptors in children that might benefit from targeted therapy using synthetic somatostatin analogues.

Animals↗

Carcinoid tumors: analysis of prognostic factors and survival in 301 patients from a referral center.

BACKGROUND: Little is known about factors related to prognosis in patients with carcinoid disease. In this study we have tried to identify such factors. PATIENTS AND METHODS: We have evaluated 301 consecutive carcinoid patients (256 midgut, 39 foregut and six hindgut) referred during 15 years for medical treatment with respect to tumor distribution, hormone production, prognostic factors and survival. RESULTS: Survival was significantly shorter in midgut carcinoid patients with > or = 5 liver metastases or with high levels of urinary 5-hydroxyindoleacetic acid, plasma chromogranin A or neuropeptide K. By univariate analysis, these variables together with the presence of carcinoid syndrome were related to a higher risk of dying. In multivariate analyses, performed in the 71 patients with full information on all variables, advanced age and plasma chromogranin A > 5000 micrograms/l were independent predictors of overall survival. CONCLUSIONS: Poor prognostic factors for midgut carcinoid patients were multiple liver metastases, presence of carcinoid syndrome and high levels of the tumor markers studied. In this study the only independent predictors of bad prognosis in midgut, carcinoid patients were advanced age, which however is inherently related to overall survival, and plasma chromogranin A > 5000 micrograms/l. Thus, chromogranin A may prove to be an important prognostic marker for patients with carcinoid tumors.

Adolescent↗

Tachykinins influence interdigestive rhythm and contractile strength of human small intestine.

The effect of the putative enteric neurotransmitters neurokinin A and substance P were investigated on human small intestinal motility. Either neurokinin A, at doses of 6-25 pmol/kg/min, or substance P at doses of 1-6 pmol/kg/min were administered intravenously to healthy volunteers over 4 hr. Neurokinin A dose-dependently increased the fraction of phase II of the migrating motor complex, contraction frequency, motility index, and amplitude of contractions. At the highest dose, neurokinin A induced a phase II-like pattern, disrupting the migrating myoelectric complex. Substance P dose-dependently increased phase II of the migrating motor complex. The contraction frequency increased slightly at the highest dose, but neither motility index nor contraction amplitude changed. It is concluded that neurokinin A and substance P stimulate small intestinal motility in man, and it can be speculated that they play a role in the control of human small intestinal motility.

Adult↗

Endotoxin actions on myoelectric activity, transit, and neuropeptides in the gut. Role of nitric oxide.

The lipopolysaccharide (endotoxin) of gram-negative bacteria has systemic effects in animals and man. Our aim was to investigate the effects of E. coli lipopolysaccharide on motility and transit through the small intestine in rats and to analyze plasma and tissue concentrations of intestinal neuropeptides. When lipopolysaccharide (20-160 micrograms/kg) was administered intravenously, the migrating myoelectric complex was replaced by spike bursts accompanied by rapid transit. Tissue concentrations of substance P and neurokinin A decreased, while plasma levels of calcitonin gene-related peptide increased N omega-Nitro-L-arginine, N omega-L-arginine methyl ester, dexamethasone, or indomethacin prevented these changes in myoelectric activity and tissue contents of neuropeptides. All of these compounds, except indomethacin, prevented the increased rate of transit. Thus, lipopolysaccharide changes motility through the nitric oxide and arachidonic pathways, resulting in rapid transit through the gut.

Animals↗

Effects of electroconvulsive stimuli and MK-801 on neuropeptide Y, neurokinin A, and calcitonin gene-related peptide in rat brain.

Rats were pretreated with 0.9% NaCl, or 0.1 or 1.0 mg/kg MK-801, an anticonvulsant and a psychotomimetic drug, and 60 minutes later given ECS or sham ECS. After six sessions the animals were sacrificed and neuropeptide Y (NPY-), neurokinin A (NKA-), and calcitonin gene-related peptide (CGRP-) like immunoreactivity (-LI) measured with radioimmunoassays. ECS increased NPY-LI in frontal cortex, striatum, occipital cortex and hippocampus, and NKA-LI in occipital cortex and hippocampus. MK-801 increased CGRP in a dose-response manner in frontal cortex, and NKA-LI in occipital cortex. Although the higher MK-801 dose reduced seizure duration by 50%, the ECS induced NPY-LI increase in striatum, occipital cortex and hippocampus, and NKA-LI in occipital cortex was not diminished. In contrast, there was a parallel decrease in seizures and NPY-LI and NKA-LI changes in frontal cortex and hippocampus, respectively. Investigation of neuropeptides in brain may contribute to understanding of the mechanisms of action of antidepressive and antipsychotic treatments and of psychotomimetic drugs.

Analysis of Variance↗

An experimental study of the neurogenic and the immunological contribution to "tennis elbow" in rats.

In the present study the content of substance P (SP)-, neurokinin A (NKA)-, calcitonin gene-related peptide (CGRP)- and neuropeptide Y (NPY)-like immunoreactivity (-LI) was measured in rats cerebrospinal fluid (CSF), plasma and perfusates (PF) from both elbow enthesis during acute inflammation. Either substance P, SP, (10-5 M, 0.01 ml) or human recombinant interleukin-1 alpha (hrIl-1 alpha, 0.01 ml) were injected into the right enthesis of the extensor carpi radialis brevis (ECRB). The left ECRB and both ECRBs of control rats, were injected with 0.01 ml saline. Samples of CSF, plasma and PF from both ECRBs were obtained at 2, 6, and 24 h following injection and neuropeptide-LI was analysed by specific radioimmunoassays. Neuropeptide-LI was compared with control values and between the treated groups. In both treated groups NKA- and CGRP-LI was increased in CSF and NKA-LI decreased in plasma, while CGRP- and NPY-LI were raised to a similarly significant degree in the enthesis of the ECRB. SP-LI was increased in ECRB PF in comparison with controls and NKA-LI levels were higher in the hrIl-1 alpha group both in comparison with controls and between treated groups. In summary an unilateral injection of either SP or hrIl-1 alpha into the enthesis of the ECRB of the rat showed a similar influence at 2, 6, and 24 h following injection. The most pronounced changes in neuropeptide-LI occurred in the ECRB PF of both treated groups.

Animals↗

Gastrointestinal hormones and gastric emptying 20 years after jejunoileal bypass for massive obesity.

OBJECTIVE: Some studies have shown a more rapid gastric emptying in obese subjects. Six to twelve months after jejunoileal bypass (JIB) neurotensin (NT) and enteroglucagon have been shown to be elevated after food intake. These hormones, together with peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) have been implicated in the reduction of upper gastrointestinal motility seen after infusion of nutrients into the ileum. AIM: To study if the postprandial gut hormone pattern and gastric emptying is altered 20 y after JIB. SUBJECTS: Seven subjects operated with JIB a mean (s.d.) 20 +/- 3 y ago, with a BMI of 44 +/- 4 kg/m2 at the time of surgery and 31 +/- 4 at present. For comparison seven sex-matched non-operated obese controls (BMI 43 +/- 3) were studied. METHODS: Serial blood samples were obtained every 10 min after intake of a 280 kcal meal. Radioimmunoassays for motilin, cholecystokinin (CCK), NT, PYY and GLP-1 were performed. Gastric emptying of a solid meal was studied using a radioactively labelled omelette (of 310 kcal) for 120 min). RESULTS: After JIB postprandial motilin, CCK, NT, PYY and GLP-1 were elevated compared to non-operated obese subjects. Similarly, basal levels of CCK, motilin, GLP-1 and PYY were elevated in the operated group. No difference was observed in the rate of gastric emptying between the two groups. CONCLUSION: Both fasting and postprandial gut hormone levels are elevated 20 y after JIB. The impact of long-term rapid stimulation of the ileum and subsequent raised gut hormone levels on gastric emptying is not clear.

Cholecystokinin↗

Reduced food intake after jejunoileal bypass: a possible association with prolonged gastric emptying and altered gut hormone patterns.

The object of this study was to examine whether eating behavior, food preference, gastric emptying, and gut hormone patterns are altered after jejunoileal bypass (JIB) in patients with severe obesity. Eight obese [mean (+/- SD) body mass index (BMI; in kg/m2) 42.9 +/- 4] subjects were studied prospectively before and 9 mo after JIB with eight age- and sex-matched normal-weight control subjects. Total energy intake, data from the universal eating monitor (VIKTOR), eating motivation measured by visual analog scales, a food-preference checklist, a forced-choice list, solid-phase gastric emptying, and postprandial concentrations of cholecystokinin, motilin, and neurotensin were studied. BMI was reduced by 29% after JIB. Compared with normal subjects, the JIB patients showed a reduced desire to eat, decreased hunger, and reduced prospective consumption before a test meal. After surgery, obese subjects selected fewer food items and showed a reduced preference for high-carbohydrate and high-fat items before a test meal. There was a trend from an accelerated toward a decelerated eating pattern in obese subjects after JIB. After JIB, gastric emptying of obese subjects was slowed and similar to that in control subjects. Obese subjects had lower postprandial cholecystokinin concentrations that were lower than those of control subjects both before and after JIB. Postprandial concentrations of neurotensin were higher after JIB. We conclude that after JIB, the desire to eat and preference for high-carbohydrate and high-fat items is reduced, resulting in decreased energy intake. That gastric emptying is prolonged and gut hormone patterns are altered with low postprandial plasma cholecystokinin and high neurotensin plasma concentrations may at least partly account for these observations.

Adult↗

Indomethacin influences regulatory peptides and increases DNA synthesis in the gastrointestinal tract of the rat.

OBJECTIVE: To examine the effect of long-term administration of indomethacin on regulatory peptides and DNA synthesis. DESIGN: Sprague-Dawley rats were treated with 1 mg/kg indomethacin subcutaneously or indomethacin and 500 micrograms/kg oral prostaglandin E2 or solvents for 2 months before labelling with methyl-3H-thymidine. METHODS: The labelling index, growth fraction and the number of epithelial cells were determined on autoradiographs of the stomach small intestine and colon. Plasma and gastrointestinal tissue concentrations of regulatory peptides were analysed by radioimmunoassay. RESULTS: Indomethacin increased the concentration of somatostatin in the gastric fundus and ileum and reduced it in the colon. Prostaglandin E2 reduced the somatostatin concentration in the duodenum and colon. Indomethacin increased the concentration of neurotensin neurokinin A and glucagon in the distal small intestine and reduced the glucagon level in the colon. Prostaglandin E2 prevented such changes. Indomethacin increased DNA synthesis in the small intestine and produced hypoplasia of the villi. These changes were prevented by prostaglandin E2, except for the villous hypoplasia observed in the distal small intestine. Prostaglandin E2 reduced the labelling index in the antrum and colon. CONCLUSION: Endogenous prostaglandins selectively modulate the synthesis and/or release of regulatory peptides and regulate the outflow of cells from the epithelial surface. Indomethacin induces hypoplasia, which triggers a secondary trophic reaction in the epithelium that may, at least partially, be mediated by regulatory peptides.

Animals↗

Prostaglandin E2 modulates serotonin- and gastrin/CCK-immunoreactive cells in the duodenal mucosa of the rat.

Groups of Sprague-Dawley rats were given placebo or prostaglandin E2 (PGE2) at 25 or 5,000 micrograms/kg or 15,R,15-methyl-PGE2 (MePGE2) at 5 or 50 micrograms/kg, twice daily, orally, for 1 month. Histological sections from the proximal duodenum were processed for immunohistochemistry and the volume density of immunoreactive endocrine cells was determined using point-counting grids. The surface density of the villous lining was estimated by using a cycloid test system. Thereafter, the total volumes of endocrine cells and the total surface area of the villous lining were calculated after estimating the mucosal volume. The volume density of serotonin-immunoreactive cells was increased in the duodenum of rats given 25 or 5,000 micrograms/kg PGE2 (p < 0.05). The total volume of these cells increased in the animals given 25 micrograms/kg PGE2 (p < 0.05). The total volume of gastrin/CCK-immunoreactive cells was higher in rats given 25 micrograms/kg PGE2 or 50 micrograms/kg MePGE2 than in controls (p < 0.05). The volume density of somatostatin-immunoreactive cells increased in rats given 5 micrograms/kg MePGE2, but the total volumes were not different between the groups. The area of somatostatin-immunoreactive cell profiles was enlarged in the animals given 5,000 micrograms/kg PGE2 (p < 0.05). The mucosal volume was enlarged by prostaglandins. The epithelial thickness increased in rats given the highest doses of PGE2 (p < 0.05). The concentration of motilin-like immunoreactivity increased in the duodenum of rats given 5 micrograms/kg MePGE2 (p < 0.05). We conclude that oral administration of PGE2 for 1 month increased the total volumes of serotonin- and gastrin-CCK-immunoreactive cells and the tissue concentration of motilin-like immunoreactivity, which indicates that prostaglandins modulate endocrine cells in a stable steady-state condition.

Administration, Oral↗