Role of 5-hydroxytryptamine in toxaemia of pregnancy

5-HT concentration in blood of 24 randomly selected pregnant women presenting with signs and symptoms of toxaemia of pregnancy were estimated and compared with 30 normal pregnant women. As such 5-HT level increases with the progress of pregnancy and in toxaemia group in comparison to normal pregnancy. A change in the degree of oedema from moderate to severe could bring a statistically significant change in blood pressure and serum 5-HT level. Increased 5-HT plays a role in toxaemia as well as in normal pregnancy and some of the toxic effects observed in toxaemia of pregnancy are due to the effects of 5-HT.

Reversible cone photoreceptor injury in commotio retinae of the macula

PURPOSE

To examine the foveal cone photopigment kinetics in two patients with commotio retinae of the posterior pole (Berlin edema).

METHODS

A noninvasive technique, called fundus reflection densitometry, was used to provide a measure of the amount of visual photopigment at the foveal area and the time constant of photopigment regeneration.

RESULTS

Strongly impaired foveal cone photopigment kinetics were found in two patients during the acute stage of commotio retinae. Complete recovery occurred within 3 months in both patients.

CONCLUSION

Retinal opacification in Berlin edema is accompanied by a traumatic lesion at the level of the photoreceptor-retinal pigment epithelium (RPE) complex. These results support recent histopathologic data on commotio retinae, which revealed moderate photoreceptor outer segment disruption and retinal pigment epithelium damage. According to our data, such damage might be reversible.

Altered inflammatory responses in leukotriene-deficient mice

Leukotrienes have been implicated in the regulation of immune responses, including inflammation and immediate hypersensitivity reactions. Here, we describe the phenotypic analysis of leukotriene-deficient mice generated by inactivation of the 5-lipoxygenase (5LO) gene. These 5LO(-/-) mice were unable to synthesize detectable levels of leukotrienes and were more resistant to lethal anaphylaxis induced by platelet-activating factor. The intensity of an acute inflammatory response induced by arachidonic acid was similar in 5LO(-/-) mice and controls. However, the response in 5LO(-/-) mice, but not in controls, could be virtually eliminated by a cyclooxygenase inhibitor. These data suggest that inflammatory responses are modulated by arachidonic acid metabolites through a variety of interconnected mechanisms. This has important implications for understanding the early events of an inflammatory response and for designing drugs for use in therapeutic intervention.

[Acute hydrops of the gallbladder in childhood]

The authors discuss four cases of acute hydrops of the gallbladder being examined in the Department of Pediatrics, Medical University School of Pécs. Diagnosis was based on ultrasonography. In all cases right upper quadrant abdominal pain and fatigue were observed. The causes of hydrops were Kawasaki's disease, sepsis, and multiple trauma. In one case the cause was unknown. In one of the cases cholecystectomy was done, in three cases the hydrops resolved spontaneously. The authors discuss the aetiology, the symptomatology and the therapeutical possibilities of hydrops. On the basis of their results the authors suggest the importance of the serial ultrasound examinations.

Reperfusion injury in skeletal muscle: interaction of osmotic and colloid-osmotic pressure in the initial reperfusate for oedema prevention

Previous studies from the authors' laboratory have shown that controlled limb perfusion after prolonged, acute ischaemia minimizes reperfusion injury. The present study was performed to investigate the role of osmotic and colloid-osmotic pressure in the initial reperfusate in order to reduce postischaemic limb oedema and subsequent reperfusion injury. A total of 96 isolated rat hindlimbs were used: 18 were perfused immediately after amputation (no ischaemia; untreated) and 78 limbs were subjected to 4 h of warm ischaemia in a moist chamber. Thereafter eight limbs were used to investigate the effects of the addition of mannitol to the initial reperfusate. The remaining 70 limbs received controlled reperfusion (modified reperfusate with various osmotic (315-580 mosmol/l) and colloid-osmotic pressure (0-50 mmHg. perfusion pressure 50 mmHg) during the first 30 min after ischaemia. Controlled reperfusion was always followed by uncontrolled reperfusion (30 min. perfusion pressure 100 mmHg) to simulate the clinical condition where normal blood perfusion at systemic pressure will follow controlled reperfusion. Functional recovery, limb weight, water content of the soleus muscle, limb flow and tissue high-energy phosphates were assessed at the end of the experiment. Results show that a reperfusate without colloid-osmotic pressure (i.e. without macromolecules) produces severe limb oedema (84.6(2.0)% water content) and allows no functional recovery after prolonged warm ischaemia. Addition of mannitol to the initial reperfusate does not prevent severe reperfusion injury. In contrast, a hyperosmotic reperfusate with a colloid-osmotic pressure of 26 mmHg effectively prevents limb oedema (78.6(0.9)% water content, 110.8(2.4)% of control weight). Physiological osmotic pressure (315 mosmol/l), however, will not reduce oedema formation (82.7(0.4)% water content). Furthermore, colloid-osmotic pressure > 26 mmHg increases the viscosity of the reperfusate (flow decreases to < 50% of control) and does not allow an optimal functional recovery. Macromolecules used to create the colloid-osmotic pressure should be of similar molecular weight to albumin (69,000 Da); those with a smaller molecular weight (e.g. hydroxyethyl starch40,000/0.5) produce excessive limb oedema (184.9(13.5)% control weight; 85.7(1.4)% water content) without functional recovery (0% control contractions). The present data suggest that after prolonged limb ischaemia: (1) addition of mannitol to a crystalloid solution does not prevent oedema; (2) hyperosmotic reperfusates (380-480 mosmol/l) with a colloid-osmotic pressure of 26 mmHg are most effective in preventing limb oedema; and (3) macromolecules used to achieve colloid-osmotic pressure should have a molecular weight similar to albumin.

Intramuscular pressure, torque and swelling for the exercise-induced sore vastus lateralis muscle

This study investigated changes in intramuscular fluid pressure (IMP), torque and swelling related to delayed onset muscle soreness (DOMS) of the vastus lateralis muscle. IMP was measured via catheterization in the unstretched (0 degree, full extension) and stretched (90 degrees of knee flexion) muscle at rest; then IMP and knee extension torque were determined during maximal contractions pre and 2 d after (post) repetitive eccentric activity in one leg for eight male subjects. DOMS of the vastus lateralis muscle was associated with a significant elevation in IMP at rest as indicated by pre (0 degree: 5.4 mmHg, 90 degrees: 80 mmHg) and post (0 degree: 8.4 mmHg, 90 degrees: 13.2 mmHg) comparisons (P = 0.02). Soreness symptoms were aggravated when the muscle was stretched and this was accompanied by a significantly higher post IMP at 90 degrees vs. 0 degree (P = 0.01). During maximal contractions, peak torque declined by 15% relative to pre and peak IMP declined by 26%; DOMS symptoms, however, were most severe during this manoeuvre. Biopsies from the sore vastus lateralis muscle revealed significantly larger fibre areas for all fibre types as compared with contralateral controls (P < 0.01); however, no differences were detected for extracellular volume percent comparisons. This study shows that DOMS of the vastus lateralis muscle is associated with extensive intracellular swelling and with elevated IMP. In line with previous studies, fibre swelling may be a common subsequence to repetitive eccentric activity; the ability of IMP measurements to detect this swelling at rest and during various manoeuvres for other muscles may depend on compartmental compliance.

Skin microvascular architecture and perfusion studied in human postmastectomy oedema by intravital video-capillaroscopy

Breast cancer treatment often causes chronic arm oedema. Oedema depends on the balance between microvascular filtration and lymph drainage, but little is known about the microvessels in postmastectomy oedema (PMO). We investigated cutaneous capillary density in PMO, since capillary density is one of the factors influencing fluid load on the lymphatic system. Video-capillaroscopy allows the skin microcirculation to be examined in vivo and recorded for later analysis. Patient arm volumes, measured optoelectronically, increased by 30 +/- 13%. The forearm skin of each arm was examined in 7 normal subjects (mean age 22 years) and 15 PMO patients (mean age 61 years). Native capillaroscopy was found to underestimate capillary density. Venous congestion increased the number of capillaries detected by native capillaroscopy by 26-28%. Fluorescein detected 19-27% more capillaries than native capillaroscopy. Using fluorescein, no significant difference in mean capillary density was found between the right (50 mm-2) and left (48 mm-2) arms of normal subjects (p = 0.53). Surprisingly, cutaneous capillary density in the swollen arm (33 mm-2) was not significantly less than in nonswollen arms (35 mm-2) of patients, despite a mean 14% increase in skin area. Capillary density decreased significantly with age. Relative to the volume and area changes, the density results indicated that cutaneous neovascularization had occurred in the swollen arm.

Corrected formula for estimating peripheral blood flow by impedance plethysmography

In this paper, the limitations of the conventional formula for the computation of peripheral blood flow from impedance plethysmograms are highlighted, and a correction to the formula is suggested. A conductivity cell experiment is described to show the dependence of the value of the blood flow index (BFI), obtained from the conventional formula, on the mean resistivity of the cell. It is also shown that the value of the corrected BFI is independent of the mean resistivity. Anomalies observed in the amplitude of systolic waves in impedance plethysmograms of patients with oedema are explained.

Effects of fluid retention on the measurement of body composition using bioelectric impedance

Body composition measurements using bioelectrical impedance analysis (BIA) were performed on 50 uremic patients immediately before and after hemodialysis (HD) therapy, on 10 uremic patients under continuous ambulatory peritoneal dialysis (CAPD) therapy before and after the fluid was drained out of the peritoneal cavity and on 3 cirrhotic patients before and after abdominal paracentesis. Thirty-two pairs of measurements were performed on the CAPD patients and 3 pairs on the cirrhotic patients. Significant increases in both resistance and reactance were noted after HD. However, resistance and reactance before and after peritoneal fluid had been drained were not significantly different. In HD, body fluid loss as estimated by BIA (LBIA) was higher than that from the body weight method (LBW). The relationship between the two is described by the equation LBW = 0.841LBIA + 0.588. The total body fat estimated before HD was significantly lower than after HD, and it was significantly higher when measured with peritoneal fluid retention than with fluid drained. Generalized edema caused an increase in resistance and reactance, while local peritoneal fluid retention did not cause any significant changes. When total body fluid is measured by the BIA method, it is often overestimated in the case of generalized edema and underestimated in case of peritoneal fluid retention. Therefore, total body fat is underestimated by BIA in generalized edema before HD and overestimated in peritoneal fluid retention.

The anti-inflammatory agent alpha-trinositol exerts its edema-preventing effects through modulation of beta 1 integrin function

Edema formation in acute inflammation can be induced through lowering of interstitial fluid pressure (Pif) and seems to involve dynamic beta 1 integrin-mediated interactions between dermal cells and extracellular matrix fibers. The present experiments investigate the role of beta 1 integrins in the control of Pif. The anti-inflammatory drug alpha-trinositol (1,2,6-D-myo-inositol trisphosphate) stabilizes Pif in acute inflammation. Pretreatment with 5 mg IV alpha-trinositol in pentobarbital-anesthetized rats inhibited the lowering in Pif and the edema formation induced by subdermal injection of anti-beta 1 integrin IgG. This stabilization of the beta 1 integrin function in vivo was paralleled by effects of alpha-trinositol on contraction of fibroblast-populated three-dimensional collagen lattices in vitro. alpha-Trinositol was additive to the known stimulatory effect of platelet-derived growth factor-BB on the final gel size in the collagen gel contraction assay. Furthermore, alpha-trinositol counteracted the inhibitory effect of anti-beta 1 integrin Fab fragments on collagen gel contraction. Finally, subdermal injection of dibutyryl-cAMP (db-cAMP) induced increased negativity of Pif to the same extent as did anti-beta 1 integrin antibodies, and in vitro db-cAMP reduced the ability of fibroblasts to contract collagen gels. The latter effect was opposed by alpha-trinositol. The data demonstrate that alpha-trinositol modulates beta 1 integrin function and may do so via intracellular pathways in turn affecting the function and/or cell surface expression of beta 1 integrins and suggest that alpha-trinositol can serve as a tool to study integrin function. Furthermore, the data indicate that the collagen contraction assays may provide important information of the control of Pif in vivo.

Opioid receptors influence spinal cord electrical activity and edema formation following spinal cord injury: experimental observations using naloxone in the rat

The possibility that opioid peptides participate in alteration of spinal cord conduction following trauma to the cord was investigated in a rat model using a pharmacological approach. Spinal cord injury was produced in urethane anesthetized animals by a longitudinal incision into the right dorsal horn of T10-11 segments (2 mm deep and 5 mm long). Spinal cord evoked potentials (SCEP) were recorded epidurally from the T9 (rostral) and T12 (caudal) segments after stimulation of the ipsilateral tibial and sural nerves at the ankle. SCEP from both rostral and caudal segments consisted of a small positive peak followed by a high negative peak. Infliction of trauma in untreated rats resulted in an immediate depression of the rostral maximal negative peak (MNP) amplitude. This depression was long-lasting. Later, a significant increase in the latency of the rostral MNP amplitude occurred. Naloxone was administered in a high dosage (10 mg/kg, i.p.) to block mu-, delta- and kappa-opioid receptors 30 min before injury. This drug treatment inhibited the immediate post-injury decrease of the rostral MNP amplitude without any significant effect on latency changes. Measurement of water content in the traumatized spinal cord segment showed a significant reduction in the drug treated animals 5 h after trauma (71.46 +/- 0.54) as compared with untreated controls (74.65 +/- 0.76). However, 1 mg or 5 mg/kg dosages of the drug were not effective in reducing the SCEP changes or edema after injury. These results strongly suggest that blockade of kappa-opioid receptors with high doses of naloxone is important in reduction of trauma induced alteration of SCEP and edema formation in spinal cord injury.

Biomechanical properties of the oesophagus damaged by endoscopic sclerotherapy. An impedance planimetric study in minipigs

BACKGROUND

The aims of the present study were to evaluate, by means of impedance plainmetry, regional differences in biomechanical properties in the normal oesophagus and the oesophagus damaged by sclerotherapy.

METHODS

Four minipigs underwent a weekly session of sclerotherapy for 4 weeks. Impedance planimetry was performed before the first session of sclerotherapy and 1 week after the last session of sclerotherapy. Investigations were performed by stepwise pressure-induced balloon distensions with concomitant measurements of pressure and luminal cross-sectional area (CSA) in the oesophagus 5 and 10 cm above the gastro-oesophageal junction (GEJ).

RESULTS

The normal oesophagus had significantly larger CSAs 5 cm than 10 cm above the GEJ (P < 0.05). Endoscopic sclerotherapy entailed an inversion (P < 0.05) of the normal oesophageal configuration, with narrowing 5 cm above the GEJ (P < 0.05) and increased CSAs 10 cm above the GEJ (P < 0.05).

CONCLUSIONS

Regional differences in CSA occur in the normal oesophagus, and sclerotherapy produces profound changes in the oesophageal configuration.

Leukocyte adhesion, edema, and development of postischemic capillary no-reflow

The aim of this study was to determine whether the formation of edema that occurs secondary to the neutrophil-dependent increase in microvascular permeability contributes to the genesis of no-reflow in postischemic skeletal muscle. To address this issue, four experimental approaches were used. In the first group, capillary perfusion was assessed in nonischemic canine gracilis muscles in which interstitial fluid volume was increased to a level similar to that in postischemic muscle. In the second and third groups, edema formation was prevented in postischemic skeletal muscles by administration of phalloidin or a hypertonic hyperosmotic saline-dextran solution (HSD; 7.5% saline-6% Dextran 70), and the extent of capillary no-reflow was assessed. In the final group of experiments, a monoclonal antibody (MAb) that binds to the common beta-subunit of the leukocyte integrin CD11/CD18 (MAb IB4) was administered after the development of postischemic edema, and capillary perfusion was determined. Formation of edema in nonischemic preparations and ischemia-reperfusion (I-R) were associated with marked reduction in the number of patent capillaries per fiber (1.2 +/- 0.1 and 0.4 +/- 0.1, respectively) compared with nonedematous nonischemic controls (2.5 +/- 0.3). Treatment with phalloidin or HSD prevented edema formation and attenuated the reduction in the number of patent capillaries per fiber (1.62 +/- 0.2 and 1.71 +/- 0.2, respectively) induced by I-R, whereas administration of MAb IB4 after the formation of edema in reperfused muscles failed to limit capillary no-reflow (0.5 +/- 0.1 patent capillaries/fiber).(ABSTRACT TRUNCATED AT 250 WORDS)

Neurogenic inflammation and lowering of interstitial fluid pressure in rat trachea is inhibited by alpha-trinositol

The effect of alpha-trinositol (D-myoinositol-1,2,6-triphosphate) on edema formation and capillary permeability in neurogenically induced inflammatory edema was investigated in rat trachea. Interstitial fluid pressure (Pif) was studied, since increased negativity of Pif contributes to edema formation in this situation. alpha-Trinositol was used because it inhibits edema formation, capillary leakage, and increased negativity of Pif in burn-injured skin. Pif was measured with sharpened glass capillaries (3 to 7 microns) connected to a servocontrolled counterpressure system after circulatory arrest (induced by intracardiac injection of saturated potassium chloride in pentobarbital anesthesia). This was done in order to avoid the edema formation associated with inflammatory reactions, which will raise interstitial fluid volume and Pif, causing the underestimation of an increased negativity of Pif. Neurogenic inflammation induced by electrical-field stimulation of the left vagal nerve (10 V, 20 Hz, 0.5 ms) lowered Pif from -1.4 +/- 0.6 mm Hg to -8.4 +/- 2.1 mm Hg (p < 0.01). Corresponding numbers after the intravenous administration of alpha-trinositol (40 mg/kg) before stimulation were -1.2 +/- 0.4 and -1.4 +/- 0.4 mm Hg, respectively (p > 0.05). Another series of animals with intact circulation was used to study the effect of vagal nerve stimulation and alpha-trinositol on edema formation (total tissue water and extravascular 51Cr-ethylenediamine tetraacetic acid-[EDTA] space) and albumin extravasation. These parameters increased significantly after vagal nerve stimulation, while intravenous alpha-trinositol (40 and 120 mg/kg), as given above, significantly attenuated this increase. Thus, alpha-trinositol prevented a lowering of Pif and the edema formation accompanying neurogenic inflammation in rat trachea.

Diuretic treatment for the sodium retention of congestive heart failure

The use of diuretics for the treatment of sodium retention in congestive heart failure was evaluated. Particular focus was given to the altered renal response to diuretics in patients with heart failure and adverse responses to diuretic therapy. Highlighted information included historical aspects of the development of diuretics, mechanisms of sodium retention, the physiologic and clinical response to diuretics, and the altered pharmacokinetics and pharmacodynamics of diuretics in congestive heart failure. Despite more than 60 years of empiric diuretic use in heart failure, the actual database regarding the long-term efficacy, adverse effects, and altered mortality outcome in heart failure is relatively small. Existent pharmacokinetic and pharmacodynamic data are typically not collected within the context of heart failure efficacy trials. In addition to altered electrolyte transport and total-body electrolyte depletion, diuretics may be associated with adverse neurohormonal activation. Thus, guidelines for acute and long-term therapy with diuretics in heart failure remain somewhat empiric. Diuretics will remain a mainstay for the treatment of edema in congestive heart failure but must be accompanied by moderate sodium restriction. However, large clinical trials of diuretics would be necessary to demonstrate that improved clinical efficacy with edema reduction is not offset by adverse effects, which include electrolyte depletion, ventricular arrhythmias, and subsequent increased mortality.

A phenomenon of paradox: myocardial reperfusion injury

Nurses who care for patients experiencing angina or myocardial infarction, receiving thrombolytics, and undergoing percutaneous transluminal coronary angioplasty or cardiac surgery should be aware of factors that contribute to myocardial reperfusion damage and dysfunction. This article reviews mechanisms identified as contributing to myocardial reperfusion injury. These include generation of oxygen free radicals, loss of antioxidant enzymes, neutrophil-initiated damage, calcium abnormalities, loss of normal adenosine triphosphate concentration, myocardial stunning, vascular endothelial and myocyte edema, hemorrhage, and reperfusion arrhythmias. This article specifically focuses on the pathophysiology of myocardial reperfusion injury and important related research.

Idiopathic oedema: a lesson in differential diagnosis

This paper outlines our approach to the diagnosis of Idiopathic Oedema. The patient presented illustrates some of the pertinent clinical and laboratory pointers one has to take into consideration before labelling a person as suffering from idiopathic oedema. The discussion also includes a brief review of the literature on the patho-physiology and management of this benign disorder.

Selection for MDR1/P-glycoprotein enhances swelling-activated K+ and Cl- currents in NIH/3T3 cells

The relationship between multidrug resistance (MDR) P-glycoprotein expression and swelling-activated Cl- and K+ conductance was investigated in mouse NIH/3T3 fibroblasts and their colchicine-selected counterparts (COL1000, high P-glycoprotein). Whole cell patch-clamp and isotopic flux experiments confirmed that swelling-activated Cl- currents were induced by 20-30% bath dilution only in the MDR-expressing cell line. However, at bath dilutions > 30%, both cell lines developed Cl- currents that reached similar large magnitudes at higher dilution levels. Thus the apparent absolute difference in cell lines at lower dilutions is due to a shift in the response curve relating hypotonicity to Cl- conductance. At all dilutions and in both cell lines, the swelling-activated Cl- currents were outwardly rectifying, active at negative cell voltages, and inactivated at positive voltages. Verapamil (100 microM) and 1,9-dideoxyforskolin (100 microM), which inhibit P-glycoprotein drug transport, did not significantly inhibit the swelling-activated Cl- conductance efflux in the COL1000 cells also showed a leftward shift in the response curve to hypotonicity. These results indicate that response curve to hypotonicity. These results indicate that colchicine-selection for increased P-glycoprotein expression did not lead to the expression of swelling-activated Cl- channels, but instead enhanced a step in the pathway from bath dilution to regulatory volume decrease that is common to both K+ and Cl- channels.

Venous reflux in patients with previous deep venous thrombosis: correlation with ulceration and other symptoms

PURPOSE

Deep vein thrombosis (DVT) in many cases leads to chronic symptoms in the damaged leg, even though the affected veins have recanalized. The major hemodynamic defect in such recanalized veins is reflux. The incidence and extent of reflux has been studied in patients with proven DVT and correlated with concurrent symptoms.

METHODS

Two hundred seventeen limbs in 183 patients were examined by duplex scanning from January 1989 to October 1992. All limbs had previous DVT diagnosed by venography. Sites and extent (proximal, distal, or both) of reflux were identified by meticulous duplex scanning of the whole venous system and correlated with presenting symptoms.

RESULTS

The patients were classified into nine groups on the basis of the classification of the system involved (superficial, deep, or superficial and deep) and whether the reflux was found proximal or distal to the knee or both. Eight-one limbs belong to chronic venous insufficiency class 1, 92 belong to class 2, and 38 belong to class 3. Reflux was confined to the deep venous system in 84 limbs (38.7%), to the superficial system in 31 (14.3%) limbs, and to both systems in 102 (47%) limbs. It was confined to proximal veins only in 48 (22.1%) limbs, distal only in 56 (25.8%) limbs and throughout the limb in 113 (52.1%) limbs. The incidence of swelling was increased by distal or a combination of proximal and distal reflux regardless of which system was involved. In limbs with superficial venous insufficiency (SVI) or deep venous insufficiency (DVI) only, the incidence of skin changes was not affected by the extent of reflux. However, in limbs with combined SVI and DVI, it was increased in the presence of reflux throughout the limb. Absence of distal reflux was associated with a low incidence of skin changes even in the presence of DVI. Ulceration increased with an increased extent of reflux in the presence of SVI. Absence of superficial reflux was associated with a low incidence, even in the presence of DVI.

CONCLUSIONS

The data suggest that as far as the skin changes and ulceration are concerned, distal reflux and reflux in the superficial veins are more harmful than reflux confined to the deep veins, even when such reflux extends throughout the deep venous system.

Oedema in patients with Addison's disease on replacement therapy: glucocorticoid excess and mineralocorticoid deficiency?

Steroid hormones influence mechanisms related to oedema formation, including postural vasoconstriction and vascular tone. We studied fifteen patients (7 male, 8 female) with primary adrenal failure on clinically optimal replacement therapy. Five patients, all female, had clinically detectable oedema. Patients with oedema had evidence of mineralocorticoid deficiency, with increased supine and erect plasma renin activity and greater postural fall in blood pressure. Mean morning plasma cortisol levels were significantly higher in the group with oedema, suggesting they were receiving insufficient mineralocorticoid and a possible relative excess of glucocorticoid. There were no significant differences between patients with and without oedema in lower-limb cutaneous blood flow or in postural vasoconstrictor responses measured by laser Doppler flowmetry. The mechanism of oedema formation is unclear, but appears not to be modulated by haemodynamic mechanisms with expansion of intravascular volume or, in contrast to the known effects of sex hormones, by impairment of postural vasoconstriction. Theoretically, excess glucocorticoid replacement may result in oedema formation, by direct action on vascular tone, by altering capillary permeability, or by influencing other factors such as atrial natriuretic peptide. Measurement of plasma renin activity in conjunction with plasma cortisol profiles may be useful in adjusting replacement therapy in patients with Addison's disease and oedema.

[Relations between acute myocardial edema, coronary vascular resistance and left ventricular mechanics in isolated rat heart]

To evaluate the effect of acute myocardial edema (ME) on coronary vascular resistance (CVR) and left ventricular (LV) mechanical function, the LV water content (% of total weight) of seven groups (n = 10 each) of isolated rat heart was determined. Group I included non-perfused hearts and served as control. Group II was perfused with Krebs-Henseleit buffer only for the brief equilibration period which preceded every experiment. Group III, IV and V were perfused for 90 min at the constant pressure of 60, 100 and 140 mmHg respectively. Group VI and VII were perfused for 90 min at the constant flow of 10 and 30 ml/min respectively. The hearts were contracting isovolumically against a fluid-filled latex balloon with fixed volume. CVR and LV functional parameters were measured throughout the whole perfusion period. The water content of Group I (78.2 +/- 0.3%) was significantly lower than Group II (80.5 +/- 0.3%). A higher degree of ME was present in groups III, IV and V (80.2 +/- 0.3, 81.4 +/- 0.3 and 83.3 +/- 0.2%, respectively), as well as in groups VI and VII (80.7 +/- 0.1 and 83.4 +/- 0.2%, respectively). CVR significantly increased over time in groups III, IV and V (about +30, +35 and +50%, respectively), as well as in groups VI and VII (about +22 and +20%, respectively). LV developed pressure did not change over time in Group III (which did not show further fluid accumulation after the equilibration period); it decreased on the other hand in groups IV (about -27%) and V (about -40%). In groups VI and VII, LV developed pressure showed as increase (about +28%) and a reduction (about -29%) respectively. In conclusion, in the isolated crystalloid-perfused rat heart, ME is directly dependent on coronary perfusion pressure and/or flow. ME induces an increase in CVR and a rapid and significant depression of LV function.

Tracheal mucosal edema in hydrostatic pulmonary edema

Airway edema has been described in heart failure, and, in animal experiments, airway narrowing was observed with elevated left atrial pressure (Pla). On the basis of double-indicator-dilution principles using helium and dimethylether, we were able to measure a water compartment of the tracheal mucosa (VH2O) in dogs. Hypervolemia with an attendant increase in Pla caused by infusion of 2 liters of dextran increased VH2O from 368 +/- 71 (SE) to 794 +/- 177 microliters (P < 0.01). Pulmonary arterial wedge and central venous pressures (Pcv) rose concomitantly. Increases in pulmonary arterial wedge and Pcv by a left atrial balloon catheter produced similar increases in VH2O, whereas increases in Pcv alone by a right atrial balloon did not increase VH2O. Increasing VH2O by dextran infusion was associated with an increase in pulmonary resistance from 1.16 +/- 0.19 to 2.15 +/- 0.24 cmH2O.l-1.s (P < 0.01). These observations show that fluid accumulation in the lung during pulmonary congestion also involves extraparenchymal airways and is related to Pla rather than right atrial pressure. This indicates that sufficient collateral drainage exists during right-sided but not left-sided pressure elevations.

Effect of a neurokinin-1 (NK1) receptor antagonist on oedema formation induced by tachykinins, carrageenin and an allergic response in guinea-pig skin

The effect of the neurokinin-1 (NK1) receptor antagonist RP67580 in modulating inflammatory oedema formation has been investigated in guinea-pig skin. Oedema formation was measured over 30 min by the extravascular accumulation of intravenously-injected 125I-albumin in the anaesthetised guinea-pig. RP67580 was injected intradermally with the agents under test. Intradermal RP67580 (10 nmol/site) inhibits oedema formation induced by substance P (30 pmol) and neurokinin A (100 pmol), but not that induced by bradykinin (10-1000 pmol) or histamine (10 nmol). Substance P-induced oedema formation is similar in control (saline) and mepyramine (histamine H1 receptor antagonist) pretreated guinea-pigs suggesting a minimal involvement of histamine in substance P induced oedema formation in guinea-pig skin. Oedema formation induced by intradermal carrageenin (0.2%) was not inhibited by RP67580 (1-10 nmol). A significant but partial inhibition of oedema formation induced in a passive cutaneous anaphylaxis (PCA) response was observed. The oedema formation in the PCA was inhibited 50% by mepyramine pretreatment but in the presence of mepyramine no further inhibition of the PCA response by RP67580 was observed.

Acute effects of TTFCA on capillary filtration in severe venous hypertension

The acute variation in capillary filtration [CF] was evaluated with strain-gauge plethysmography in patients with severe venous hypertension due to deep venous disease. Two groups were selected and randomly treated with a single oral dose or TTFCA (60 mg or 120 mg). CF was assessed again after 5 and 10 hours. Eleven patients were randomised in the 60 mg group and 9 in the 120 mg group. Also 5 normal subjects were studied with the same procedure to act as controls. No variations in CF were observed in normal limbs. In both groups of patients there was a significant decrease in CF after 5 and 10 hours. The percent decrease in CF after 10 hours was higher in the high dose group. These results indicate that TTFCA is acutely effective in reducing CF and oedema in subjects with venous hypertensive microangiopathy. The effects of TTFCA on CF appear to be dose related.

Mediation by bradykinin of rat paw oedema induced by collagenase from Clostridium histolyticum

1. Collagenases are thought to play a major role in the pathology of gas gangrene caused by Clostridium histolyticum, because they can destroy the connective tissue barriers. We investigated possible mediators involved in the oedema formation and plasma protein extravasation which follow the injection of a collagenase (EC 3.4.24.3) from Clostridium histolyticum into one hind paw of anaesthetized rats. 2. The magnitude of the oedema following a subplantar injection was dependent on the dose of collagenase (30, 100 and 300 micrograms) injected. It reached its maximum within 30 min and remained unchanged for at least 5 h. Plasma protein extravasation into the paw was most pronounced within 20 min of the injection. Heat-inactivated collagenase was ineffective. 3. The B2 bradykinin (BK) antagonist icatibant (D-Arg-[Hyp3-Thi5-D-Tic7- Oic8] bradykinin, formerly named Hoe-140) reduced oedema formation in a dose-dependent manner with a maximal reduction of around 65% at a dose of 100 nmol kg-1 (s.c.). A significant effect could already be observed at a dose of 10 nmol kg-1. The duration of the effect of icatibant (100 nmol kg-1) was found to be at least 3 h. These results demonstrate the high potency and long duration of action of icatibant. Pretreatment of rats with the bradykinin B1 antagonist, des-Arg9-[Leu8]-BK did not affect collagenase-induced paw oedema. Thus, the observed collagenase-induced effects are mainly mediated by BK through activation of B2 receptors. 4. Pretreatment of adult rats with capsaicin (125 mg kg-1, s.c.) three weeks before the collagenase injection caused a significant attenuation of the paw oedema and of plasma extravasation but was significantly less effective than icatibant (100 nmol kg-1, s.c.). The non-peptide substance P antagonist,CP-96,345 (l0 micromol kg-1, i.v.) significantly reduced collagenase-induced oedema formation to a degree comparable with that seen after capsaicin pretreatment. The inhibition by the substance P antagonist was significantly smaller than that seen after icatibant. The inhibitory effect of icatibant in capsaicin pretreated rats, or of icatibant together with CP-96,345 in untreated rats, was not greater than that oficatibant alone in rats treated with the vehicle for either capsaicin or CP-96,345. CP-96,344(10 micromol kg-1, i.v.), the inactive enantiomer of CP-96,345, did not affect collagenase-induced paw oedema. In capsaicin-pretreated rats, CP-96,345 (10 micromol kg-1, i.v.) did not reduce collagenase-induced paw oedema.The subplantar injection of bradykinin (30 nmol) induced a paw oedema comparable with that induced by collagenase (100 microg). CP-96,345 (10 micromol kg-1, i.v.), but not CP-96,344 (1O micromol kg-1, i.v.),significantly reduced the bradykinin-induced paw oedema. These findings indicate that collagenase leads to the release of bradykinin; bradykinin then stimulates afferent C-fibre terminals and causes the release of substance P and probably also neurokinin A, which augment the oedema-inducing effect of bradykinin.5. Indomethacin or mepyramine plus cimetidine failed to inhibit collagenase-induced paw oedema.Thus, prostaglandins and histamine do not seem to be involved in collagenase-induced paw oedema.6. After subplantar injection of collagenase, the sensitivity scores in a modified formalin-test rapidly increased during the first 10 min. This increase was abolished by pretreatment with icatibant(100 nmol kg-1, s.c.) indicating that the stimulation of nociceptive afferent neurones following injection of collagenase is due to the action of released kinins.7. In conclusion, bradykinin appears to be the main mediator of inflammation induced by a collagenase from Clostridium histolyticum. As well as having direct relevance to a known pathological condition,collagenase-induced paw oedema could prove to be a useful model in inflammation research and in the investigation of bradykinin antagonists. The present results might provide an experimental basis for clinical investigations of the effects of icatibant in infectious diseases where the release of collagenases from bacteria causes rapid spreading of inflammation.