[Effects of endolymphatic lymph stimulation on draining and transporting function of the lymphatic system in experimental peritonitis]

Bacterial aggression and tissue destruction during experimental peritonitis cause progressive disorders of blood and lymph microcirculation, paralleled by increase of the coagulation potential of the blood and lymph, activation (during the first 12 hr) of the drainage function of the lymph system, followed in 24 h by a drop of lymph flow and its complete blocking in 48-72 h. This is caused by disseminated microhemo- and lymphothrombosis with decompensation of the drainage and transporting functions of the lymph system during this period of the disease. Lymphogenic effect of endolymphatic stimulation by drugs in experimental peritonitis is notably (by 1.8-4.5 times) higher than the effect of routine lymph stimulation with the same drugs and their combinations.

Experimental study of cardiac lymph dynamics and edema formation in ischemia/reperfusion injury--with reference to the effect of hyaluronidase

This study is designed to evaluate the effect of hyaluronidase on the canine myocardial edema derived from ischemia/reperfusion injury. The mongrel dog's heart received 90 minutes of ischemia under cardiopulmonary bypass consisting of 30 minutes of normothermia alone and 60 minutes of hypothermia with cardioplegic arrest. Reperfusion for 60 minutes was added thereafter. Two kinds of cardioplegic solution, 4 degrees C St. Thomas' Hospital solution with or without 3000 units/L of hyaluronidase, were prepared. The solution was given antegradely every 30 minutes during cardioplegic arrest. Cardiac lymph was collected continuously from the afferent duct of the cardiac lymph node by cannulation. Hyaluronidase in the cardioplegic solution increased cardiac lymph volume significantly and improved postischemic recovery of cardiac function. A high level of adenosine triphosphate was maintained at that time. The myocardial water content at the end of reperfusion revealed a minimum increase with hyaluronidase use. Active drainage of cardiac lymph by hyaluronidase alleviates the myocardial edema formation, thereby preserving cardiac function.

Alpha-trinositol reduces edema formation at the site of scald injury

BACKGROUND

The effects of alpha-trinositol (1D-myo-inositol-1,2,6-triphosphate, IP3) on burn-induced edema formation were investigated.

METHODS

Lymph flow (QL; microliter/min) and lymph-to-plasma protein ratio (CL/CP) were monitored in groups of five to six dogs before and 4 hours after (1) a 5-second 100 degrees C or 90 degrees C foot paw scald; (2) IP3 (45 mg/kg intravenous bolus, then a 20 mg/kg/hr infusion) 30 minutes before or after 100 degrees C scald, or 30 minutes after 90 degrees C scald. Hind paw venous pressure was elevated and maintained by outflow restriction until reaching steady state QL and (CL/CP)min. Macromolecular reflection coefficient (1-CL/CP) was measured. Fluid filtration coefficient (Kf; ml/min/mm Hg/100 gm) was calculated. Relative paw weight gain (%) was measured.

RESULTS

Compared with preburn values, scald uniformly produced significant increases in QL, CL/CP, and Kf, IP3 significantly (p < 0.02, ANOVA) reduced paw weight gain when given before, but not after, 100 degrees C burn (41% +/- 5% versus 18% +/- 7% preburn IP3 and 31% +/- 3% postburn IP3). Compared with 90 degrees C burn animals, postburn treatment significantly (p < 0.017) attenuated 4-hour increases in QL (550 +/- 87 versus 252 +/- 29 microliters/min), Kf (0.016 +/- 00 versus 0.007 +/- 00 microliter/min/mm/Hg/100 gm), and relative paw weight gain (28% +/- 3% versus 12% +/- 5%).

CONCLUSIONS

alpha-Trinositol given after a 90 degrees C scald blunted edema formation at the site of scald, likely through reduced transmembrane fluid flux.

Deep cervical lymph flow following the infusion of mannitol in rabbits

Jugular lymph flow of anesthetized rabbits in response to infusion of mannitol solutions differing in osmolarity were measured. Either an isotonic (310 mosmol), hypotonic (100 mosmol), or hypertonic (605 mosmol) mannitol solution was infused into either the internal carotid artery (ICA) or the right lateral ventricle (RLV). Lymph was collected continuously and measured over a 60 min preinfusion period, as well as during mannitol infusion and intermittent recovery periods. The mean peak flow rates of hypertonic infusion for the first 30 min via ICA and RLV were 2.2 +/- 0.4 (12% decrease) and 5.0 +/- 1.0 microliter/min (72% increase), over those of isotonic infusates which were 2.5 +/- 0.3 microliters/min (via ICA) and 2.9 +/- 0.5 microliters/min (via RLV), respectively. In contrast, lymph flow rates of hypotonic infusate for the first 30 min via ICA and RLV were 3.9 +/- 0.8 microliters/min and 2.3 +/- 0.4 microliters/min, respectively. A decrease both in intracranial pressure and in lymph flow following hypertonic mannitol infusion via ICA were observed. However, intracranial pressure and lymph formation were increased following hypertonic infusion via RLV. The results indicate that the changes in jugular lymph flow could be affected by the changing in osmolarity of mannitol infusate.

Effects of inhaled nitric oxide and extracorporeal membrane oxygenation on pulmonary hemodynamics and lymph flow in oleic acid lung injury in sheep

OBJECTIVE

To compare the effects of inhaled nitric oxide (NO) and extracorporeal membrane oxygenation (ECMO) on oxygenation, hemodynamics, and lymphatic drainage in an oleic acid lung injury model in sheep.

DESIGN

Prospective, randomized study.

SETTING

Animal research laboratory.

ANIMALS

Thirty female sheep, weighing 35 to 40 kg.

INTERVENTIONS

Acute lung injury was induced by central venous injection of oleic acid (0.5 mL/kg body weight). A chronic lymph fistula had been prepared through a right thoracotomy 3 days before the experiment. Animals were assigned randomly to the NO group (n = 14) or the ECMO group (n = 16). When a lung injury score of > 2.5 was achieved, the animals were given NO in dosage increments of 2, 5, 10, 20, and 40 parts per million (ppm), or placed on ECMO with an FIO2 of 0.21 (ECMO-21) and then 1.0 (ECMO-100) at the oxygenator. Mechanical ventilator parameters were kept constant to isolate the effects of NO and ECMO on systemic and pulmonary hemodynamics, cardiac output, oxygenation parameters, lymph/plasma protein ratio, and lymph flow. Measurements and calculations were performed after 1 hr at each individual step of NO concentration or FIO2.

MEASUREMENTS AND MAIN RESULTS

In the ECMO group, PVRI and MPAP did not change and were significantly different from the NO group. In the NO group, there was a dose-dependent decrease in venous admixture, maximal at 10 ppm NO and decreasing from 40 +/- 6% to 23 +/- 10% (p < .05). This decrease was significantly different from the ECMO group, where there was no change. There was a significant increase in PaO2/FIO2 in the NO group, maximal at 10 ppm NO (84 +/- 11 to 210 +/- 90, p < .05), but a greater increase in PaO2/FIO2 on ECMO-21 (81 +/- 14 to 265 +/- 63) and a further increase on ECMO-100 (398 +/- 100) (p < .05). The lymph/plasma protein ratio remained unchanged in both groups after induction of lung injury by oleic acid. However, lymph flow decreased by 11 +/- 6% in the NO group, whereas it increased by 14 +/- 17% in the ECMO group (p < .05).

CONCLUSIONS

In an oleic acid-induced sheep model of acute lung injury, there were significant differences between the effects of NO and ECMO on acute pulmonary hypertension, hypoxemia, hypercarbia, and lymph flow. NO significantly decreases pulmonary hypertension, whereas pulmonary hemodynamics were not substantially affected by ECMO. Both interventions reversed hypoxemia, but ECMO did so to a greater degree, and only ECMO improved hypercarbia. Only NO decreased lymph flow, possibly as an effect of decreased microvascular filtration pressure. This study did not attempt to evaluate the impact of these interventions on ventilatory requirements, barotrauma, or outcome. However, this model suggests that NO therapy may moderate pulmonary hypertension and improve lymph flow in acute lung injury. Clinical studies are needed to assess whether NO therapy might be beneficial in treatment of severe acute lung injury in older children and adults.

Changes in myocardial fluid filtration are reflected in epicardial lymph pressure

The effect of increased fluid filtration on stopped-flow epicardial lymph pressure (P(lymph)), used as an indicator of myocardial interstitial volume, was investigated in the anesthetized open-chest dog. Histamine infusion resulted in an increased systolic peak in the P(lymph) signal together with an increase in diastolic P(lymph) in four of five animals. During reactive hyperemia, systolic and diastolic P(lymph) increased to 127 +/- 8 and 121 +/- 6.7% (mean +/- SE, n = 6) of control, respectively. Peak P(lymph) was approximately 15 s later than peak coronary blood flow and venous pressure (P(ven)). When P(ven) was transiently elevated to 367 +/- 72 (systolic) and 247 +/- 45% (diastolic) of control, P(lymph) increased to 132 +/- 12 and 120 +/- 5.5% of control. The time of response was similar for P(ven) and P(lymph) (t50 approximately 2 S). The increased systolic and diastolic P(lymph) can be explained by an increase in interstitial and lymph filling. It is concluded that changes in myocardial fluid filtration are reflected in epicardial P(lymph). Furthermore, it seems that cardiac contraction constitutes an important defense mechanism against the formation of myocardial edema.

[The effect of cystamine on the level of postradiation peroxidation products in the lymph of dogs]

The experiments on irradiated dogs with a drained pectoral lymph duct revealed an early accumulation of radiotoxins (diene conjugates and malonic dialdehyde) in the lymph and blood plasmas and; simultaneously, a lowering of water-soluble antioxidants. The prophylactic application of cystamine improved the drain-detoxifying function of the lymphatic system, lowered the level of radiotoxins, and aided in the antioxidant properties of lymph and blood plasmas.

[Endolymphatic therapy and current detoxication methods in the treatment of peritonitis]

An original method of endolymphatic therapy with the stimulation of the lymph outflow was developed and used in 108 patients with peritonitis. The dynamics of intoxication parameters was studied during the endolymphatic therapy, indirect electrochemical oxidation of blood, photochemotherapy and traditional treatment. The method proposed has been found to be most efficient. The method of endolymphatic therapy with the lymph stimulation allowed lethality from peritonitis to be decreased to 7.4%.

Secretory leukoprotease inhibitor attenuates lung injury induced by continuous air embolization into sheep

Continuous air embolization (CAE) into the pulmonary arterial circulation of sheep results in functional and structural changes of chronic pulmonary hypertension. Release of elastin peptides into lung lymph during CAE and attenuation of CAE-induced pulmonary hypertension by neutrophil depletion suggest that neutrophil elastase may contribute to these changes. To investigate this notion, we treated awake sheep with a potent neutrophil elastase inhibitor, recombinant secretory leukoprotease inhibitor (SLPI) (100 mg/day by aerosol), during 12 days of CAE (CAE+SLPI; n = 7). Controls included sheep receiving CAE + vehicle (VEH) (n = 6), VEH alone (n = 3), and SLPI alone (n = 3). SLPI significantly attenuated the CAE-induced increases in lung lymph flow (day 8; 2.3 +/- 0.5 vs. 5.6 +/- 1.7 ml/15 min), protein clearance (day 8; 1.36 +/- 0.32 vs. 3.08 +/- 0.84 ml/15 min), and elastin peptide concentration (day 8; 243 +/- 41 vs. 398 +/- 44 ng/ml). SLPI delayed the onset of sustained pulmonary hypertension from day 8 to day 12. Both CAE groups showed similar structural changes in the pulmonary arteries. SLPI was well tolerated in control sheep and did not affect hemodynamics or structure. We conclude that serine proteases may contribute to the early initiation of chronic pulmonary hypertension but do not play a striking role in its eventual development.

A lymphatic function of Daflon 500 mg

The lymphagogue activity of a micronized, purified flavonoidic fraction, Daflon 500 mg (D) (diosmin 90%+ hesperidin 10%) was tested in dogs and rats.

METHODS

In the anaesthetized mongrel dog measurement of lymphatic flow was carried out in a thoracic duct fistula inserted 30 min prior to I.V. injection of D (3.125; 6.250 and 12.500 mg/kg-1). Lymph was collected every 10 min for 200 min. Using the same experimental model 14C-diosmin transfer from blood to lymph was studied after I.V. infusion (5 min) of 14C-diosmin (50 muCi)+D(12.5 mg/kg-1) in the saphenous vein. Similar experiments were performed in the rat after oral treatment.

RESULTS

D induced an important lymphatic flow increase which was correlated with the administered doses. The maximal 10 min period flow after I.V. injection of D (12.500 mg/kg-1) was 191% higher than the corresponding one in the control group. A correlation between lymphatic flow increase and pulsatility was demonstrated. Infusion of 14C-labelled-D evidenced a clear blood-lymph transfer of the drug: an active transport into the lymph was suggested during a 15 min-100 min period from the concentration curves.

CONCLUSIONS

The improvement of lymphatic drainage displayed by D seems to be an important component of its beneficial effect on perivascular edema.

Effect of acute administration of bleomycin on lung fluid balance in sheep

This study examined the effects of acute administration of bleomycin (BLM) on lung liquid and protein exchange in anesthetized sheep prepared with caudal mediastinal lung lymph fistulas. Six sheep received BLM (15 U IV) after a baseline period, while seven others were given BLM after a steady state was obtained following elevation of left atrial pressure (PLA), a procedure intended to minimize changes in pulmonary microvascular surface area and produce high lung lymph flow (QL). Plasma and lung lymph angiotensin converting enzyme (ACE) activities were measured in order to independently assess the effects of BLM on pulmonary endothelial integrity. QL rose significantly in all animals following BLM. The ratio of lymph to plasma protein concentration (CL/CP) did not change in the group given BLM alone, and fell continuously during the period of PLA elevation after BLM in that group. Plasma and lung lymph ACE activities were unchanged following BLM administration in either group. The ultrastructure of the gas-exchanging region of lungs from animals in each group was examined by transmission electron microscopy. The data suggest that acute administration of a low dose of BLM does not increase pulmonary microvascular permeability, but may induce an increase in perfused pulmonary microvascular surface area responsible for increased QL.

Effect of a combination of coumarin derivatives and rutoside on venous and lymphatic circulations during severe constriction of the caudal vena cava in rabbits

The effect of a coumarin (CAS 91-64-5) derivatives-rutoside (CAS 153-18-4) combination (Esberiven) has been investigated in an in vivo model of venous hind leg stasis elicited by severe constriction of the caudal vena cava in anesthetized rabbits. The vena cava flow is initially reduced by 80% compared to reference values; then, it significantly declines over time. The venous femoral pressure drops as well as the perfusion pressure whereas the peripheral resistance increases. The popliteal lymph flow gradually slows down after the constriction. Moreover, this venous constriction results in a marked reduction of the right ventricular stroke volume responsible for a left ventricle failure and for the exitus of 30% of the rabbits within 1-3 h post-constriction. A 5-day pretreatment (i.v.) with the coumarin derivatives-rutoside combination at a dose of 4 mg of coumarin derivatives + 200 mg of rutoside/rabbit/day increases the lymph flow but does not suppress the mechanically-induced venous flow decrease. The 6th-day treatment (infusion at the respective doses of 5 mg of coumarin derivatives + 250 mg of rutoside/kg or 10 mg of coumarin derivatives + 500 mg of rutoside/kg) induces a dose-related significant increase of both venous and lymph flows and of the femoral pressure. At the same time, the peripheral venous resistance decreases in a dose-response relationship. Furthermore, after administration of coumarin derivatives and rutoside, the right ventricle stroke volume increases and no death occurs.

Effects of methysergide administration on edema formation at the site of scald

Femoral blood flow (Qa), hind paw lymph flow (Qlym), and lymph-to-plasma protein concentration ratio (Clym/Cp) were monitored before and 4 h after 1) 5-s 100 degrees C paw scald, 2) methysergide (1 mg/kg iv) 20 min before scald, 3) methysergide 30 min after scald, and 4) methysergide only. Before experimentation, hind paw venous pressure was elevated and maintained until steady-state Qa, Qlym, and minimal Clym/Cp levels were reached. The reflection coefficient (sigma d) was determined as 1 - minimal Clym/Cp; the filtration coefficient (Kf) was calculated. Methysergide alone caused no changes. Increases in Qa, Qlym, Clym/Cp, and Kf were identified in all scald groups. Compared with scald only animals, pre- and postscald methysergide blunted the increases in Qa, Qlym, Kf, and paw weight gain without an effect on sigma d. These data demonstrate that methysergide reduces edema formation at the site of scald, perhaps by modulating the burn-induced vasodilator response and/or by limiting the burn-induced increase in microvascular surface area.

Hyaluronan efflux from canine lung with increased hydrostatic pressure and saline loading

Although lymphatic washout of hyaluronan during lung hydration has been postulated to deplete lung interstitial hyaluronan content and thereby contribute to the decreased interstitial exclusion of albumin observed under these conditions, this hypothesis has not been directly tested. In anesthetized, ventilated mongrel dogs, a prenodal lung lymphatic was cannulated for measurement of lymph flow and hyaluronan concentration. Following baseline measurements, Pla was increased in four steps of 5 cm H2O in Group 1 or set to one pressure ranging between 6 and 32 cm H2O in Group 2. In Group 3, saline (15% body weight) was infused over 30 min and then Pla increased as in Group 2. Invariably, as lymph flow increased in Groups 1 through 3, lymph hyaluronan concentration and hyaluronan flux increased significantly (p < 0.05). In a separate control group, there were no changes in lymph flow, hyaluronan concentration, or hyaluronan flux. In Group 3, lung hyaluronan content at 5 h (0.76 +/- 0.08 mg/g dry weight) was not significantly less than that during baseline (0.88 +/- 0.05 mg/g dry weight), although total uronic acid content actually increased by 38% over the same time course. In contrast, in the control group, both lung hyaluronan and uronic acid content remained stable over the experimental period. From these data, approximately 2 to 3% of lung hyaluronan is predicted to leave the interstitium via lymphatic flux per day under baseline conditions. The daily turnover of interstitial hyaluronan by this route increased to 15 to 18% of total content when Pla was elevated and to 54% following saline infusion. Thus, lung hyaluronan can be rapidly mobilized with increased lymph flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Lymphatic mast cell response and effect of compound 48/80 on popliteal lymph node reaction in rats following intracutaneous injection of Staphylococcus aureus

To investigate the significance of mast cells in the popliteal lymph node during the development of an inflammatory response, rats were inoculated with 12 x 10(7) colony-forming units of Staphylococcus aureus in the hind foot pad. Numerical changes in mast cells were then measured in the corresponding popliteal lymph node. Six days after inoculation, despite the enlargement of the responding lymph node, a marked decrease in granulated mast cell number, relative to the contralateral node, was observed in the cortical and medullary compartments. Popliteal lymph nodes from rats treated with compound 48/80 and then inoculated with S. aureus showed a higher cortical and medullary hypertrophic response and a significant increase in degranulated/weakly basophilic mast cell number in the lymph node tissue. The findings suggest that (1) Staphylococcus aureus induces a reduction in granulated mast cell number in the cortical and medullary compartments of regional lymph nodes; (2) pretreatment with compound 48/80 appears to contribute to the lymphoid cell proliferation and the hypertrophic response of lymph nodes induced by S. aureus; and (3) granulated mast cells have a regulatory role on lymphoid cell proliferation.

Increased hyaluronan flux in canine paw lymph is induced by histamine and the histamine-releasing agent compound 48/80

The present experiments investigated hyaluronan (HYA) flux from skin of pentobarbital anesthetized mongrel dogs when transcapillary fluid flux was increased by local intraarterial injection of histamine (50 micrograms) or Compound 48/80 (C48/80) (100 micrograms) inducing mast cell degranulation. A prenodal lymphatic draining the hindpaw was cannulated and the paw flexed passively at 50 times/min. Grand mean (n = 18) of control lymph flow and HYA concentration was 16 +/- (SD) 14 microliters/min and 8.8 +/- 2.3 micrograms/ml, respectively. Lymph flow increased 11- and 15-fold within 10 min after histamine and C48/80 injection, respectively, and returned to control values after 3 h for histamine while it did not return fully in the C48/80 group. HYA concentration decreased by 30 and 40% during the first hour after histamine and C48/80, respectively, while HYA flux increased 11-15 times control. Control experiments (saline vehicle) showed an unexpected and gradual increase in HYA concentration during the 8-hour experimental period, regardless of unchanged lymph flow. This increase became statistically significant at the end of the experimental period, suggesting either an increased synthesis or increased rate of release of bound HYA from the paw. The present data show that HYA is loosely bound and easily mobilized from the interstitial matrix and that histamine and C48/80 cause a release of bound HYA from the interstitium. An increase in HYA concentration towards the end of the 8-hour experimental period most likely represents an increased synthesis of HYA.

Pharmacologic properties of Daflon 500 mg

AIMS AND METHODS

Some pharmacologic activities of a micronized flavonoid complex consisting of 90% diosmin + 10% hesperidin (Daflon 500 mg*) have been investigated by use of various experimental models: (1) interference with mechanisms of edema (synthesis of arachidonic acid derivatives, microvascular hyperpermeability induced by bradykinin, ischemia, or streptozotocin), (2) interference with lymphatic drainage (thoracic duct fistula in the dog).

RESULTS

Daflon 500 mg inhibited prostaglandin E2 (PGE2) and thromboxane A2 (TxA2) synthesis during a one-month oral daily treatment (100 mg.kg-1.day-1) in the rat, after induction of chronic inflammation by subcutaneous implantation of sponge fragments. Microvascular hyperpermeability induced by bradykinin or ischemia in the rat cremaster muscle was reduced after an oral treatment with Daflon 500 mg (100 mg.kg-1 twice daily). Microvascular hyperpermeability of the streptozotocin-induced diabetic rat was antagonized when Daflon 500 mg (300 mg.kg-1 once daily) was given orally as a preventive treatment. In the anesthetized dog, an increase in lymphatic flow, correlated with administered doses, was observed after IV injection of Daflon 500 mg. Lymphatic flow was maximal twenty minutes after injection of the drug (12.5 mg.kg-1) and was three times higher than the basal flow.

CONCLUSION

The protective effect of Daflon 500 mg against the formation of perivascular edema and its therapeutic value in the treatment of venous stasis could be explained by its inhibitory activity on the inflammatory process or ischemia-induced hyperpermeability and by its stimulatory effect on the pulsatile activity of lymphatic vessels.

Blood-to-lymph migration of small lymphocytes through the liver of the sheep

The process of lymphocyte migration is required for the systemic dissemination of immunological memory and immune surveillance. We report here experiments to quantitate the normal traffic of lymphocytes that occurs from blood to lymph through the liver and hepatic node in the sheep. Comparisons were made with known lymphocyte homing pools. Individual afferent hepatic lymphatics had cell outputs of 1.4 +/- 0.1 x 10(6) cells/hr, suggesting that the total combined lymphocyte output from the liver was no greater than about 1 x 10(7) cells/hr. The lymphocyte output in efferent hepatic lymph was 6.2 +/- 0.4 x 10(7) cells/hr, comparable to the cell outputs recorded from other lymph nodes of similar size. When the specificity of lymphocytes homing through the liver or hepatic node was examined, we found similarities to both the peripheral lymph node and intestinal lymph node homing patterns. Migration into afferent hepatic lymph was found to be different from that into intestinal or subcutaneous efferent lymph, and the kinetics of migration into hepatic afferent lymph was faster than that observed into efferent compartments. Intravenously injected endotoxin was found to alter the normal lymph flow through the liver tissue and the hepatic node; it appeared to enhance the migration of macrophages out of the liver by way of the afferent lymph. These studies suggest unique features of lymphocyte traffic through the liver and the need for further experiments on hepatic lymphocyte traffic, particularly in pathological states with substantial mononuclear cell infiltration.

[The activity of the lymphatic vessels under conditions of experimental stress exposures]

Lymphangions were found to possess a considerable ability for temperature adaptation under modelled stressful effects on humans. The minute volume of lymphangions was found to linearly depend on the temperature of bathing solution within the range of 22-41 degrees C. Aspirin and other non-steroid analgetic agents were found to exert an obvious dose-dependent negative inotropic effect on electric potentials and contractile activity of a lymphangion. Clinical-experimental assessment and physiological justification of action of a new perfusion solution: polyvisoline, was given.

Dynamics of glucose production and uptake are more closely related to insulin in hindlimb lymph than in thoracic duct lymph

We previously reported a striking similarity between the dynamics of both glucose turnover and thoracic duct lymph insulin during euglycemic clamps (J Clin Invest 84:1620, 1989), which suggested that transendothelial insulin transport (TET) is rate-limiting for insulin action in vivo. Thoracic duct lymph, however, is primarily derived from insulin-insensitive tissues, which raises questions as to the physiological significance of this relationship. The relationship between glucose turnover and TET was thus examined in insulin-sensitive tissues by the simultaneous measurement of insulin in plasma, thoracic duct lymph, and hindlimb lymph during euglycemic clamps in normal anesthetized dogs (n = 8). Clamps consisted of two 3-h phases: a 0.6 mU.min-1.kg-1 insulin infusion (activation phase) followed by termination of the insulin infusion (deactivation phase). Lymph insulin was less than plasma insulin during both phases (P < 0.01) with steady-state hindlimb (120 +/- 12 pM) and thoracic duct lymph insulin (138 +/- 12 pM) 38 and 45%, respectively, lower than steady-state plasma insulin (222 +/- 24 pM) at the end of the activation phase (P < 0.05). Also, the rate of increase of lymph insulin was slower than plasma insulin during hormone infusion; half-time to steady-state was 8.8 +/- 2.0 min for plasma insulin, but longer for thoracic (25.8 +/- 3.5) and hindlimb lymph insulin (40.7 +/- 5.7 min). A very close relationship was observed during activation between the rate of increase of glucose uptake (Rd) and the increase in hindlimb lymph insulin (r2 = 0.92); this relationship was weaker for thoracic lymph (r2 = 0.74) and much weaker between glucose uptake and plasma insulin (r2 = 0.35). These data support the concept that interstitial insulin (represented by hindlimb lymph) is the signal that determines glucose uptake by insulin-sensitive tissues and that the rate of increase of glucose uptake is determined by transendothelial insulin transport into insulin-sensitive tissue. Also, during activation, hindlimb lymph insulin was a very strong predictor of the rate of suppression of hepatic glucose output (HGO) (r2 = 0.96), and the correlation with HGO was stronger than that for thoracic lymph (r2 = 0.85). The evidence that the rate of increase of Rd and the rate of suppression of HGO during insulin infusion are very strongly predicted by the time course of insulin in hindlimb lymph is consistent with the single-gateway hypothesis: the insulin transport rate across endothelium in insulin-sensitive tissue (skeletal muscle) determines the rate of glucose utilization and the suppression of hepatic glucose output.(ABSTRACT TRUNCATED AT 400 WORDS)

A comparative study of intravenous versus intralymphatic interleukin-2, with assessment of effects of interleukin-2 on both peripheral blood and thoracic-duct lymph

Recombinant human interleukin-2 (IL-2) was administered by the intravenous (i.v.) or intralymphatic (i.l.) route to 14 patients with advanced malignancy. IL-2 was given in doses of 600,000 IU/kg or 1,050,000 IU/kg daily x 5. Thoracic duct (TD) catheters were placed, and both TD lymphocytes (TDL) and peripheral blood lymphocytes (PBL) were studied. Five of eight patients at the 600,000 IU/kg dose experienced grade III toxicity as did five of six patients at the 1,050,000 IU/kg dose. Two episodes of grade IV toxicity were seen at the higher dose. The i.l. and i.v. routes had a similar toxicity profile excepting lymphangitis/pedal infection, seen only with i.l. administration. One partial response was seen in a patient with renal cell carcinoma. Lymphopenia was seen early in therapy, with lymphocytosis by day 6. Lymphoid yield of the TD catheter fell early in therapy, then increased over baseline by the end of treatment. Intralymphatic administration resulted in a prolonged serum t1/2 and lower serum levels than did i.v. administration, but resulted in higher TD levels. Antibodies against IL-2 were ubiquitous but had no clear effects. Lymphocyte trafficking studies suggested that IL-2 affected lymphocyte redistribution to liver, spleen, bone marrow, and lymph nodes. NK activity and phenotype and LAK activity increased in response to IL-2, with no advantage for TDL. Tumor necrosis factor-alpha and gamma-interferon levels increased sporadically with treatment. The i.l. route offered no advantage over the i.v. route, and TDL offered no advantage over PBL.

The effects of high-dose vitamin C therapy on postburn lipid peroxidation

The effects of vitamin C treatment (14 mg/kg/hr) on postburn lipid peroxidation were evaluated in 12 dogs. A lymph duct above the ankle was cannulated bilaterally. Hourly lymph flow rates, plasma and lymph total protein concentrations, and plasma and lymph malondialdehyde concentrations were measured before the burn injury and for 24 hours after the burn injury. Four groups were employed: nonburn without treatment, nonburn with vitamin C treatment, burn without treatment, and burn with vitamin C treatment. The nonburn groups showed no significant differences in lymph flow rates, total protein flux, or lymph malondialdehyde level. In the burn groups the postburn hourly lymph flow rate increased by 850% without treatment and by 500% with vitamin C treatment, whereas the postburn hourly total protein flux increased by fiftyfold and twentyfold, respectively. There was a significant reduction in the postburn lymph malondialdehyde level in the group treated with vitamin C as compared with the nontreatment group. We conclude that high-dose vitamin C administration diminishes early postburn lipid peroxidation and reduces microvascular leakage of fluid and protein.

Effects of intravenous pentafraction on lung and soft tissue liquid exchange in hypoproteinemic sheep

Effects of infusing pentafraction (Pen), a synthetic hydroxyethyl starch plasma volume expander, on lung and soft tissue lymph flux were compared in nonanesthetized sheep that were protein depleted by batch plasmapheresis. Pen (5%) was infused to raise pulmonary arterial wedge pressure by 5 mmHg for 2 h (1.8 +/- 0.3 l). Pen raised plasma osmotic pressure from plasmapheresis baseline (10.7 +/- 2.2 mmHg; preplasmapheresis baseline, 19.6 +/- 0.6 mmHg) to 16.6 +/- 2.4 mmHg. After Pen, lung lymph flows peaked at 3.9 +/- 2.0 times a preplasmapheresis baseline value of 1.0 (plasmapheresis baseline, 2.7 +/- 0.7), but soft tissue lymph flows rose insignificantly. Plasma Pen concentrations were 2.3 +/- 1.0% postinfusion and 1.6 +/- 0.3% at 12 h. Pen mean molecular masses at these times, measured by high-performance liquid chromatography, were 160 +/- 44 and 129 +/- 23 kDa, respectively. In lung lymph, Pen concentrations were 0.8 +/- 0.6% postinfusion and 0.7 +/- 0.2% at 12 h, with mean molecular masses of 125 +/- 44 and 112 +/- 18 kDa, respectively. In soft tissue lymph Pen was nearly undetectable postinfusion, but at 12 h concentrations averaged 0.3 +/- 0.2% with a mean molecular mass of 80 +/- 10 kDa. The osmotic effectiveness of Pen may be related to its molecular mass, which was large enough to restrict filtration so that the plasma-to-lung lymph osmotic pressure gradient widened. Pen remained effective in the circulation for at least 24 h.