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Biomedical subjects

E Theodorsson

Publications and source records attributed to E Theodorsson.

At least 145 records · Page 8Linked to original sources
PubMed1994

Short-term effects of eating on vasoactive hormones and haemodynamics in patients with heart failure.

OBJECTIVES: To investigate if eating can influence the measurements of vasoactive hormones or their relationship to important haemodynamic variables. DESIGN: Haemodynamic variables and plasma concentrations of atrial natriuretic peptide (ANP), arginine vasopressin and angiotensin enzyme (ACE) activity were measured. During the 24-h study period the patients ate ordinary hospital meals and thus were studied both in the absorptive and post-absorptive phases. SETTING: Two university hospitals in Sweden participated in the study. SUBJECTS: Ten patients with heart failure, due to ischaemic heart disease. INTERVENTION: Eating. MAIN OUTCOME MEASURES: Change in haemodynamic variables and plasma concentrations of vasoactive hormones related to eating. RESULTS: After a meal (absorptive phase) pulmonary capillary wedge pressure and plasma concentrations of ANP were significantly lower compared to the postabsorptive phase, 13 +/- 1.7 vs. 16 +/- 1.9 mmHg and 57 +/- 9.5 vs. 72 +/- 12.2 pmol l-1, respectively. The relationship between ANP and its main predictor, pulmonary capillary wedge pressure, was not altered during the study period. Plasma concentration of arginine vasopressin, ACE activity and mean right atrial pressure decreased with time and the cardiac index increased with time over the study period. CONCLUSIONS: A meal may significantly influence plasma concentrations of ANP. Studies on vasodilator treatment and its interactions with ANP should take account of these basal fluctuations. The present data confirm previous reports on haemodynamic improvement during the first 24 h of supine cardiac catheterization in patients with heart failure, and add new information about decreasing concentrations of arginine vasopressin and ACE.

Aged↗
PubMed1994

Renal effects of human atrial natriuretic peptide in patients after major vascular surgery.

The effects were studied postoperatively of an infusion of atrial natriuretic peptide (ANP) 7.5 pMol.kg-1.min-1 on renal function and haemodynamics in seven patients who had been operated with insertion of an abdominal aortic graft. Urine flow, glomerular filtration rate (GFR), renal plasma flow (RPF) and excretion of electrolytes and osmoles were measured for three periods of 20 minutes during infusion of ANP, in the morning of the day after surgery. Haemodynamic studies were conducted, and serum levels of ANP, catecholamines and plasma renin activity were measured. ANP levels increased from 52 to approximately 250 pMol.L-1 during ANP infusion and decreased after infusion to a level equal to baseline. GFR increased from 92 mL.min-1 by 58, 20 and 21%, respectively. RPF was unchanged. Urine flow rate increased from 1.99 mL.min-1 by 81, 151 and 173%, respectively. Fractional clearances of sodium, chloride and osmoles were increased during the second and third ANP periods whereas fractional potassium clearance did not change during the study. There were no changes in catecholamine levels or plasma renin activity during the study. Heart rate, mean arterial pressure and calculated systemic and pulmonary vascular resistance did not change whereas reductions occurred in cardiac index, mean pulmonary artery pressure, pulmonary artery wedge pressure and mean right atrial pressure. We conclude that infusion of ANP also in the postoperative situation increases GFR, diuresis and sodium excretion.

Adult↗
PubMed1994

Plasma neuropeptide Y in healthy children: influence of age, anaesthesia and the establishment of an age-adjusted reference interval.

Plasma concentrations of neuropeptide Y, analysed in 112 healthy children, decreased significantly with age, while sex, discomfort induced by the sampling procedure or induction of general anaesthesia did not have a significant influence. An age-adjusted upper reference limit was established and proved to be useful when tested prospectively in 56 children with tumours. Two of 18 children with preliminary diagnosis of rhabdomyosarcoma had elevated plasma neuropeptide Y; both showed malignant ectomesenchymoma (p < 0.01), a mixed tumour with neural crest features. Among 38 children with neural crest derived tumours, all 7 with benign ganglioneuromas had plasma neuropeptide Y concentrations below the reference limit, while 13 of 31 with neuroblastoma had elevated concentrations (p < 0.05). Only neuroblastoma patients with elevated plasma neuropeptide Y had a poor outcome; 10 of 13 died, whereas all with normal concentrations are alive after 3-74 months of follow-up (p < 0.001).

Adolescent↗
PubMed1994

Influence of angiotensin converting enzyme inhibition on relation of atrial natriuretic peptide concentration to atrial pressure in heart failure.

OBJECTIVE: To examine the relation between haemodynamics and atrial natriuretic peptide concentration during short term angiotensin converting enzyme inhibition. DESIGN: Patients were randomly allocated to receive placebo or one of three doses of the angiotensin converting enzyme inhibitor ramipril. SETTING: Cardiac units of two tertiary referral hospitals. SUBJECTS: 38 Patients with stable congestive heart failure caused by ischaemic heart disease. METHODS: Data were collected over a 24 hour period and assessed with the aim of distinguishing between the haemodynamic effects on plasma concentrations of atrial natriuretic peptide and the direct effects of the study drug, vasopressin concentrations, and angiotensin converting enzyme activity. RESULTS: Pulmonary capillary wedge pressure was the main predictor of the plasma concentration of atrial natriuretic peptide. A higher plasma concentration of this peptide with a given pulmonary capillary wedge pressure was found after 24 hours of treatment with 2.5 mg and 5 mg of ramipril. Plasma concentration of the active metabolite, change in arginine vasopressin concentration or degree of angiotensin converting enzyme inhibition did not significantly predict change in plasma concentration of atrial natriuretic peptide or in the ratio of atrial natriuretic peptide concentration to pulmonary capillary wedge pressure. CONCLUSIONS: A gradual increase in plasma concentration of atrial natriuretic peptide with a given pulmonary capillary wedge pressure, occurs during short term high degree inhibition of angiotensin converting enzyme. The causative mechanisms are yet to be identified. Such a change in the relation between central haemodynamics and atrial natriuretic peptide concentration may contribute to the beneficial effects of angiotensin converting enzyme inhibition in patients with congestive heart failure due to ischaemic heart disease.

Aged↗
PubMed1994

Increased basal concentrations of plasma endothelin in borderline hypertension.

BACKGROUND: There is evidence for an altered endothelial function in established hypertension but little is known about endothelial function in borderline hypertension. It has also been suggested that the early stages of hypertension are characterized by an increased sympathetic drive. OBJECTIVE: To investigate whether alterations in endothelin, neuropeptide Y (NPY) and calcitonin gene-related peptide (CGRP) are already present in the borderline hypertensive stage. DESIGN: A case-control study of age-matched men recruited from a population screening programme. METHODS: Seventy-five men with stable borderline hypertension [diastolic blood pressure (DBP), 85-94 mmHg] and 75 age- and sex-matched normotensive controls (DBP < or = 80 mmHg) were investigated. Plasma samples were drawn in a standardized fashion, and extracted and analysed using competitive radio immunoassays. RESULTS: Basal concentrations of NPY and CGRP were similar in the two groups (28.4 versus 26.7 pmol/l and 24.2 versus 21.7 pmol/l, respectively). Basal concentrations of endothelin were significantly higher in the borderline hypertensive group (2.0 versus 1.5 pmol/l, P < 0.0001). CONCLUSIONS: These results suggest that a disturbed endothelial function, represented by endothelin, could be involved in the early hypertensive processes. They also suggest that these changes could be present before the basal sympathetic/parasympathetic drive alters, warranting further research into this area.

Adult↗
PubMed1993

Endothelin concentrations in respiration-related structures of the medulla during the perinatal period of the rat.

Endothelin-like immunoreactivity (ET-LI) was quantified in the developing (foetal and postnatal) rat brain stem and cerebellum using radioimmunoassay. The brain stem structures chosen for this study were (a) dorsal medullary region (DMR) including the region of nucleus tractus solitarius where the peripheral chemoreceptor afferents are known to terminate, (b) ventral medullary region (VMR) where the central chemoreceptors are thought to be located and (c) cerebellum (CER), as a control area. Compared to the prenatal period, significantly elevated concentrations of ET-LI were detected in the early postnatal period and thereafter the concentrations decreased: DMR and VMR: in comparison to the prenatal concentrations, a two-fold increase was found on the day of birth which further increased significantly (P < 0.001) on postnatal day 1 only in the region of DMR; CER: low concentrations of ET-LI were found in the early postnatal period which were not significantly different from the prenatal values. No ET-LI could be detected in any of the three regions in the adult rats. The results are discussed in view of the hypothesis that (1) endothelin appears to play an important role in the perinatal period and (2) it is involved in the chemoreceptor pathway.

Animals↗
PubMed1993

Bilateral changes of substance P-, neurokinin A-, calcitonin gene-related peptide- and neuropeptide Y-like immunoreactivity in rat knee joint synovial fluid during acute monoarthritis.

It has been hypothesized that the nervous system contributes to the symmetrical response in rheumatoid arthritis. In order to elucidate this, the bilateral concentrations of substance P-like immunoreactivity (SP-LI), neurokinin A-LI (NKA-LI), calcitonin gene-related peptide-LI (CGRP-LI) and neuropeptide Y-LI (NPY-LI) in rat synovial fluid during acute monoarthritis were studied. Equal volumes (0.05 ml) of either Freund adjuvants, carrageenan 2%, substance P 10(-5) M or human recombinant interleukin-1 alpha were injected into the right and saline into the left knee joint. Control rats were given saline bilaterally. Perfusates were obtained from both knees simultaneously at 2, 6 and 24 h after injection and were analysed by specific radioimmunoassays. Increase of SP-, NKA-, CGRP- and NPY-LI in synovial fluid occurred in both knees after injections with the pro-inflammatory substances into the right joints as compared to controls, except for unchanged SP-LI in the right knee joint after 24 h following hrIL-1 alpha injection. There was, however, generally no significant difference in the peptide contents between the right knee (injected with pro-inflammatory substance) as compared to the left knee (given saline) at 2, 6 or 24 h after injection except at three occasions. The results show that experimentally induced monoarthritis induces bilateral changes in synovial fluid peptide content.

Acute Disease↗
PubMed1993

Neuropeptide Y in neuroblastoma: increased concentration in metastasis, release during surgery, and characterization of plasma and tumor extracts.

Five children with neural crest tumors (two ganglioneuromas, one ganglioneuroblastoma, and two neuroblastomas) were investigated regarding neuropeptide Y-like immunoreactivity (NPY-LI) in tumor tissue and plasma at diagnosis and during surgery. Radioimmunoassay of extracted plasma revealed higher NPY-LI at diagnosis of neuroblastoma (640 and 230 pmol/L resp) than ganglioneuroblastoma or ganglioneuroma (74, 45, and 26 pmol/L resp). During surgery of neuroblastoma plasma NPY-LI increased two- to four-fold while no peroperative increase was seen in the other children. NPY-LI was considerably higher in neuroblastoma tissue (220 pmol/g and 144 pmol/g) than in ganglioneuroblastoma (40.2 pmol/g), ganglioneuroma (0.6 and 4.4 pmol/g), or healthy adrenal tissue (5.5 pmol/g). The highest NPY-LI concentration was found in neuroblastoma metastasis, 3,091 pmol/g. Gel-permeation chromatography of a neuroblastoma tumor showed that a majority of NPY-LI was representing intact NPY (NPY 1-36) while metastasis and plasma from the same child mainly contained smaller immunoreactive fragments. High concentrations of systemic NPY in neuroblastoma patients are of tumoral origin. Plasma levels of NPY and its fragments can be useful in diagnosing and monitoring neuroblastoma, and for early detection of relapse or metastatic disease. A possible involvement of NPY in neuroblastoma tumor growth and spread deserves further investigation.

Child↗
PubMed1993

An epithelial-dependent contracting factor induced by calcium influx in guinea-pig trachea.

The effects of epithelium removal were studied on the contraction induced by Ca2+ in K(+)-depolarizing solution, and by the calcium ionophore A 23187 in guinea-pig isolated tracheal strips. Epithelium removal reduced the maximal response to Ca2+ in K(+)-depolarizing solution and caused a significant shift to the right of the Ca2+ concentration-response curves. The contraction induced by the calcium ionophore A 23187 (10(-6) M) was also markedly reduced by epithelium removal. These results suggest the occurrence of an epithelium-derived contracting factor. The effects of hexamethonium, atropine, spantide and thiorphan showed that acetylcholine and neurokinins play a minor role in the Ca(2+)-induced contraction. The epithelium-dependent potentiation of the calcium- and of the A 23187-induced contractions was inhibited by an antibody selective for rat calcitonin gene-related peptide (rCGRP alpha). Therefore, CGRP-like immunoreactive material may be part of the epithelium-dependent contracting factor of guinea-pig trachea. Comparison of concentration-response curves for rCGRP alpha in epithelium-free and in intact guinea-pig tracheal strips suggests that an epithelium-dependent contracting factor may be mobilized by CGRP.

Acetylcholine↗
PubMed1993

Epinephrine reduces the severity of catheter-induced urethral inflammation by action at the alpha 2-adrenoceptors.

We have studied the contribution of epinephrine to experimentally induced urethral inflammation in the rat. Inflammation was induced by inserting latex strips into the urethra. The effects of various experimental procedures were assessed according to a 4-point scale based on histological findings. The results showed that 0.5 mg/kg epinephrine decreased the severity of catheter-induced urethral inflammation. This effect was blocked by the alpha 2-adrenergic agonist, yohimbine, but not by alpha 1 (prazosin), beta 1 (M32 MTC), or beta 2 (butoxamine) antagonists. The results suggest that the suppressive effect of epinephrine is mediated by action at the alpha 2 adrenergic receptor.

Animals↗
PubMed1993

Interstitial cystitis: correlation with nerve fibres, mast cells and histamine.

Interstitial cystitis (IC) is a painful condition in the urinary bladder of unknown aetiology and pathogenesis. To assess the contribution of the nervous system to IC a biopsy was taken from 6 patients with IC and from a control group of 6 patients with non-ulcerative IC. Mast cells were counted and histamine measured in bladder washings from all patients. There were significantly more nerve fibres within the sub-urothelium and detrusor muscle in chronic IC than there were in non-ulcerative IC. The bladder washings from all patients with IC contained mast cells and histamine, while only occasional mast cells and traces of histamine were found in washings from patients with non-ulcerative IC. There was a good correlation between the number of nerve fibres and number of mast cells as well as between the number of nerve fibres and the amount of histamine.

Aged↗
PubMed1993

Relation between intra-articular temperature of the arthritic temporomandibular joint and presence of calcitonin gene-related peptide in the joint fluid. A clinical study.

Arthritic temporomandibular joints were investigated for intra-articular temperature and joint fluid content of calcitonin gene-related peptide. Eleven patients (16 joints) with rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, or chronic unspecific polyarthritis or monarthritis participated in the study. The intra-articular temperature varied between 35.5 and 37.5 degrees C, with a mean of 36.5 degrees C. The concentration of calcitonin gene-related peptide varied between 7.5 and 749.0 pmol/l, with a mean of 108.6 pmol/l. There was a positive correlation between the intra-articular temperature and the joint fluid concentration of calcitonin gene-related peptide. The plasma level of the peptide was on an average 5% of the joint fluid level.

Adult↗
PubMed1993

Relation between the intra-articular temperature of the temporomandibular joint and the presence of neuropeptide Y-like immunoreactivity in the joint fluid. A clinical study.

Arthritic temporomandibular joints were examined for the joint fluid content of neuropeptide Y-like immunoreactivity (NPY-LI) and the intra-articular temperature at two separate sessions. Sixteen patients (23 joints) with rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and unspecific polyarthritis or monarthritis were investigated in this study. The intra-articular temperature ranged between 35.6 and 37.5 degrees C. The concentration of NPY-LI ranged between 72.1 and 4466.0 pmol/l and was above the normal plasma level in all patients. The intra-articular temperature was negatively correlated with the joint fluid concentration of NPY-LI. Moreover, patients with low intra-articular temperature and high concentration of NPY-LI had a shorter duration of TMJ symptoms than those with high intra-articular temperature and low concentration of NPY-LI.

Adult↗
PubMed1993

Pancreaticobiliary juice releases motilin during phase I of the migrating motor complex in man.

The effect of duodenal perfusion with pancreaticobiliary juice on plasma motilin was investigated in eight fasting subjects. The study was undertaken with recording of gastrointestinal motility, to predict spontaneous fluctuations in plasma motilin levels. Duodenal perfusion with pancreaticobiliary juice or saline at a rate of 5 ml/min for 10 min was performed in random order after the second or third activity front. The 30-min integrated plasma motilin response was significantly greater after perfusion with pancreaticobiliary juice: 1.5 (0.7-2.3) nmol x min/l (mean and 95% confidence interval), compared with 1.0 (0.5-1.5) nmol x min/l after saline (p < 0.05). Although perfusion with pancreaticobiliary juice was followed by endogenous plasma motilin peaks after about 20 min in six of eight subjects, the mean interval to the next activity front was not significantly different. In conclusion, duodenal perfusion with pancreaticobiliary juice in phase I of the migrating motor complex releases plasma motilin without affecting the fasting motility pattern.

Adult↗
PubMed1993

Plasma concentrations and urinary excretion of regulatory peptides in patients with urticaria pigmentosa.

Patients with urticaria pigmentosa were investigated during symptom-free interval regarding plasma concentrations and urinary excretion of immunoreactive regulatory peptides: calcitonin gene-related peptide (CGRP), gastrin, neurokinin A (NKA), neuropeptide Y (NPY), somatostatin (SOM), substance P (SP) and vasoactive intestinal peptide (VIP). The plasma concentrations of these peptides, except for CGRP, were below the detection limit. The urinary excretion of the regulatory peptides were not higher in the patient group than in the controls, but in individual patients there was high urinary excretion of SP and VIP. A lower urinary excretion of CGRP was found in the patient group in addition to a tendency to a lower plasma concentration.

Adolescent↗
PubMed1993

Rapid induction of enterochromaffinlike cell tumors by histamine2-receptor blockade.

The effect of acid inhibition on gastric endocrine cells was investigated in Praomys (Mastomys) natalensis. Long-term treatment (1 to 32 weeks) with an irreversible histamine 2-receptor blocker (loxtidine) caused a sustained increase in plasma gastrin levels, which was accompanied by a gradual increase in histamine and histidine decarboxylase activity of the gastric oxyntic mucosa. The density of endocrine cells in the oxyntic mucosa increased gradually, doubled by 8 weeks, and was three times that of controls after 24 weeks of treatment. Hyperplastic changes in the endocrine cell population were evident after 2 to 8 weeks in all animals, whereas dysplastic or neoplastic lesions were observed in half the animals after 16, 24, and 32 weeks of treatment. Gross tumors in the oxyntic mucosa were observed in 1/4 of the animals treated for 24 or 32 weeks. Proliferating cells were identified as enterochromaffinlike cells because they were argyrophilic and immunopositive for chromogranin A and histamine. The results demonstrate that histamine 2-receptor blockade initiated by loxtidine promotes a rapid development of enterochromaffinlike cell tumors in Mastomys and suggest a critical role for gastrin in the formation of these tumors. However, the rate and frequency by which carcinoid tumors appeared in Mastomys after acid inhibition was much greater than that reported in other species, indicating that several factors, including hormonal and genetic factors, are important in the development of gastric endocrine tumors.

Animals↗
PubMed1993

Vasoactive agents and blood pressure regulation in sequential ultrafiltration and hemodialysis.

Hypotension is a common and sometimes dangerous side effect of hemodialysis. Its etiology is multifactorial and largely unknown. Earlier studies on the role of endogenous blood pressure regulating agents such as catecholamines and renin have rendered conflicting results. We studied the influence of ultrafiltration and isovolemic hemodialysis separately on the plasma concentrations of the following blood pressure regulating agents: adrenaline, noradrenaline, dopamine, neuropeptide Y, calcitonin gene-related peptide (CGRP), renin (PRA), angiotensin II, vasopressin, aldosterone and cortisol. During isolated ultrafiltration, plasma levels of two strong vasoconstrictors (noradrenaline and angiotensin II) and one strong vasodilator (calcitonin gene-related peptide, CGRP) increased significantly (noradrenaline 3.24 +/- 0.60 nM to 4.31 +/- 0.55 nM; p = 0.032, angiotensin II 19.74 +/- 3.46 pmol/l to 28.49 +/- 7.24 pmol/l; p = 0.047) No symptomatic hypotension occurred. At the end of isovolemic hemodialysis, plasma levels of all the vasoconstricting agents had decreased to pretreatment values, but those of CGRP had continued to rise (from 85.3 +/- 17.6 pmol/l to 114.5 +/- 25.3 pmol/l, p = 0.031). During isovolemic hemodialysis, blood pressure fell to symptomatic levels, but was restored at the end of treatment. The study shows that hemodialysis patients respond to fluid removal by ultrafiltration with an increase in plasma levels of CGRP, noradrenaline and angiotensin II. The net effect is an appropriate vasoconstriction and adequate blood pressure is maintained during isolated ultrafiltration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗