Left Thoracic Duct Research Articles

Ultrasound analysis of cervical thoracic duct for patients with constrictive pericarditis and chylothorax.

To analyze ultrasound features of cervical thoracic duct for patients with constrictive pericarditis and chylothorax. Patients were retrospectively assessed. The patients were divided into a non-pleural effusion (PE) group (n = 54), a chylothorax group (n = 23), and non-chylothorax group (n = 28). Conventional ultrasound was used to obtain the maximum inner diameter and collapse of the inferior vena cava, the inner diameter of left cervical thoracic duct, and the frequency of opening of the valve at the end of the left thoracic duct. Contrast ultrasonography was used to score the reverse flow of the thoracic tube. The percentage of PE was 48.5%, and the percentage of chylothorax was 21.9%. The three groups had significant differences in five parameters. The inner diameter of left cervical thoracic duct was correlated with the degree of central venous pressure. Contrast ultrasonography was effective in quantitative assessment of the degree of intravenous-thoracic cord reverse flow which correlated with all parameters of central venous pressure. Thoracic duct dilation and regurgitation secondary to central venous pressure can lead to chyloreflux disorder and may be the mechanism of chylothorax occurrence in constrictive pericarditis.

Tuberculous Dactilitis in Young Male, a Rare Case

Introduction : Chylothorax is an uncommon medical condition caused by the accumulation of chylous fluid in the pleural space. Chylothorax has no predilection for sex or age. The prevalence after various cardiothoracic surgeries is 0.2% to 1%. Mortality and morbidity rates are around 10%. Respiratory distress may occur due to compression of the lung by the accumulated fluid. Management and approaches to treating the condition require multidisciplinary therapy, starting from non-pharmacological, pharmacological, to interventional management. Case Report : A 57-year-old Man patient was referred to the emergency room with chief complaint of shortness of breath. Reduced breathing sound on both lung fields. No previous history of cancer or thoracic surgery were found. X-ray examination had found bilateral pleural effusion. Thoracocentesis and pleural fluid analysis was performed with total of 6800 cc serosanguinous, whitish fluid was extracted from both of the lung. The patient was diagnosed with chylothorax. Lymphangiography and embolization was performed on the leak on left thoracic duct (T10) from right lymph node. Antibiotic was also given to treat the community acquired pneumonia that could be one of the possible etiology on this patient. Dietary modification with low fat diet and Ocreotide was also given to this patient as one of the treatment modalities. Discussion : The diagnosis of Chylothorax on this patient was established based on pleural fluid analysis and evidenced by lymphangiography examination by the presence of a leak in the thoracic lymphatic duct. Various modalities to diagnose this condition have been carried out with inconclusive results. Non-pharmacological, pharmacological and radiological interventions with embolization through lymphangiography are proven to be able to stop leaks and reduce symptoms in this patient. Conclusion : Chyle leak to the pleural space may compress the lung and cause respiratory distress. Combinaton of thoracocentesis, embolization of the leakage, dietary intake modification and administration of ocreotide may help prevent further chylous fluid accumulation.

Abstract No. 546 Thoracic duct variants: what are they, and which ones pose the greatest challenge for cannulation?

Thoracic duct embolization (TDE) is a minimally invasive treatment for chylous pleural effusions and, in many cases, is used as a first-line intervention. Arguably the most difficult part of a TDE is percutaneously accessing the thoracic duct, a task made even more difficult in the presence of anatomic variants. We describe several thoracic duct anatomic variants and which variants posed the greatest challenge in cannulation. 75 patients undergoing TDE between 2010 and 2018 were identified. Imaging was reviewed to determine thoracic duct anatomy. Procedural and clinical notes were reviewed to determine patient outcomes. Of the 75 patients, 50 patients (66.7%) had standard thoracic duct anatomy, 13 (17.3%) had an absence of cisterna chyli (CC), 5 (6.7%) had a persistent right thoracic duct, 3 (4%) had a proximal duplication of the thoracic duct, 2 (2.7%) had plexiform ducts, 2 (2.7%) had persistent left thoracic duct. Of the patients with standard thoracic ducts, 40 cannulation attempts were made and 30 were successful (75%). The most common variant encountered, absence of the CC posed the greatest challenge when performing percutaneous access. In the 13 patients with an absence of a CC, 9 cannulation attempts were made with only 4 succeeding (44%). Cannulation was not attempted in 4 patients because of a lack of an adequate percutaneous target. In the two patients with plexiform ducts, cannulation was attempted in both but only 1 was successful. In the patients with persistent right-sided course, persistent left-sided course, and a proximal thoracic duct duplication, all cannulation attempts were successful. Knowledge of commonly encountered thoracic duct variants can help predict the likelihood of a challenging cannulation. The absence of CC and plexiform duct may be predictive of technical failure of the procedure. Novel techniques or procedural adjustments are necessary to address thoracic duct variants encountered during TDE.

Evaluation of the left neck distal thoracic duct in cirrhosis with computed tomography

ObjectiveTo evaluate the left distal thoracic duct (DTD) in the lower neck area by using contrast-enhanced chest computed tomography (CT) in patients with liver cirrhosis (LC). MethodsIn 156 consecutive subjects who performed the contrast-enhanced chest CT, examinations were retrospectively reviewed. The diameters of the left DTD were measured by using CT. Depending on the diameter of the left DTD, the left DTD configurations were classified into four grades: grade 0 (no identification of DTD), grade I (diameter <5mm), grade II (diameters ≥5mm and <10mm), and grade III (diameter ≥10mm). Depending on the liver status, all 156 subjects were divided into three groups: (a) noncirrhotic liver group (n=55), (b) compensated LC group (n=88), and (c) decompensated LC group (n=13). ResultsAmong the 156 left DTD configurations, 81 (52%), 60 (39%), 10 (6%), and only 4 (3%) were assigned to the grade 0, I, II, and III, respectively. The noncirrhotic liver group included 45 (82%) grade 0 and 10 (18%) grade I subjects. The compensated LC group included 37 (42%) grade 0, 50 (57%) grade I, and 1 (1%) grade II subjects. In contrast, the decompensated LC group included 9 (69%) grade II and 4 (31%) grade III subjects. ConclusionWhen reviewed the contrast-enhanced chest CT, the left DTD can be identified more frequently in subjects with LC than in those with noncirrhotic liver. Furthermore, the degree of left DTD dilation may be associated with the severity of LC.

Primary idiopathic chylopericardium: Report of two cases

Primary chylopericardium is an extremely rare disease. This report presents two cases of this disease, in a 47-year-old man and 21 -year-old woman. Both cases were given diagnosis of primary chylopericardium by chylous pericardial fluid examination and lymphangio-scintigraphy which demonstrated abnormal communication between the left thoracic duct and the pericardial cavity.

Changes in left thoracic duct lymph flow during progressive anemia in the ovine fetus

OBJECTIVE: The purpose of this study was to evaluate the extent to which increased lymph flow can return fluid and protein to the circulation in the chronically anemic fetus. STUDY DESIGN: Thoracic duct lymph flow rate over a range of outflow pressures was measured in 8 near-term fetal sheep 4 to 5 days after surgery and daily thereafter for 5 days. After each day's study 60 to 150 ml of blood was withdrawn at a rate of 1 ml per minute. Regression analysis was used to establish the lymph flow function curve. Lymph and plasma protein concentrations and lymph flow rate were compared by analysis of variance for repeated measures. RESULTS: As the hematocrit was reduced from 34.6% ± 1.3% (mean ± SE) to 14.4% ± 1.0%, thoracic duct lymph flow increased from 0.12 ± 0.01 to 0.28 ± 0.02 ml/min/kg. Plasma total protein concentration did not change, lymph protein concentration fell (2.6 ± 0.1 to 2.4 ± 0.1 gm/dl), and the difference between plasma and lymph protein concentrations increased (1.04 ± 0.05 to 1.34 ± 0.10 gm/dl). Protein returned to the circulation increased from 11.5 ± 0.3 to 23.7 ± 1.5 mg per minute. Central venous pressure did not change and remained less than the breakpoint pressure. Although the plateau lymph flow rate increased, neither the breakpoint or stopflow pressures of the lymph flow function curve were altered. CONCLUSIONS: Fetal lymph flow and thereby capillary filtration increased progressively as anemia became more severe. The increase in lymph flow did not appear to be limited by outflow pressure. By returning protein to the circulation, an increase in thoracic duct lymph flow helped to limit expansion of extravascular fluid volume during chronic fetal anemia. (AM J OBSTET GYNECOL 1996;174:1469-76.)

Dependence of physical performance on the state of lymph circulation

We carried out 2 series of experiments to determine physical performance under conditions of preliminary ligation of the main lymphatic collectors. In the first series, animals (dogs) were divided into three groups. In 3 dogs of the 1st (control) group, the left and right lymphatic ducts were simultaneously isolated (without dressing) with subsequent suturing of the wound. In 5 animals of the 2nd group, the ligation of the left thoracic lymphatic duct in the cervical spine was performed, and in 3 of the 3rd group, simultaneous ligation of both the left and right thoracic lymphatic ducts in the cervical spine was performed.

Thoracic duct lymph flow responses to hemorrhage in the ovine fetus.

Blood volume returns toward normal after hemorrhage much more rapidly in the fetus than in the adult due to a rapid entry of fluid and plasma proteins into the fetal circulation. One potential source of fetal fluids and plasma proteins is the lymphatic system, since basal lymph flow rate and interstitial protein concentration are high in the fetus. Furthermore, studies in adults suggest that lymph flow rate may increase following hemorrhage. To test the hypothesis that hemorrhage induces an increase in lymph flow in the fetus, 15 late-gestation ovine fetuses underwent left thoracic duct catheterization with low-resistance catheters and were studied 5 or more days after surgery at 134 +/- 1 (SE) days gestation. The protocol included three successive 30-min periods: control, hemorrhage, and recovery. During the first 5 min of the hemorrhagic period, 61 +/- 4 ml of fetal blood were removed. The blood was reinfused over the first 5 min of the recovery period. After the hemorrhage, fetal arterial pressure, venous pressure, and heart rate decreased (analysis of variance, P < 0.001). These variables significantly increased above basal levels following blood reinfusion. Fetal hematocrit (P < 0.001) and plasma protein concentration (P < 0.05) also decreased after the hemorrhage and returned to control values after the reinfusion. Fetal lymph flow rate was 0.55 +/- 0.06 (SE) ml/min before the hemorrhage and decreased by a maximum of 30.3 +/- 6.3% (P < 0.001) at 8 min after the end of the hemorrhage. Lymph flow rate was reduced by an average of 19.1 +/- 6.6% during the hemorrhagic period and returned to prehemorrhage levels following blood reinfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood volume response to drainage of left thoracic duct lymph in the ovine fetus

Although it is known that left thoracic duct lymph flow rate in the ovine fetus is several times that in the adult relative to body weight, the role of the lymphatic system in maintaining fetal blood volume has not been explored. In the present study, the left thoracic lymph duct was drained without return to the fetal circulation in 10 chronically catheterized animals for 7 h. Four experiments in which the lymph was returned to the circulation served as control. During the 7-h drainage, the total volume drained was 174.4 +/- 19.6 ml. Thoracic duct lymph flow rate decreased gradually and averaged 22.2 +/- 3.4% (SE) below control at 6-7 h compared with a small increase in the control experiments (analysis of variance: P = 0.0013 comparing 2 groups). Fetal blood volume decreased (P < 0.0001) by 8.2 +/- 1.1% at 3 h because of a decrease in plasma volume with a further small decrease in blood volume to 9.7 +/- 0.9% below normal at 7 h. The decreases in blood volume at 1, 3, 5, and 7 h were 49.5, 40.2, 24.6, and 21.7%, respectively, of the volume of lymph that was drained. Fetal vascular pressures and heart rate did not change significantly. Although protein concentrations in plasma (-6.8 +/- 1.3%) and lymph (-7.5 +/- 2.1%) decreased, the lymph-to-plasma protein concentration ratio remained constant at 0.72 +/- 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)

Maximal lymph flow in the ovine fetus

This study was designed to determine the maximal left thoracic duct lymph flow rate in late-gestation ovine fetuses. Chronically catheterized sheep fetuses (n = 8) with indwelling left thoracic lymph duct and vascular catheters were studied > or = 5 days after surgery at 136 +/- 1 (SE) days' gestation. To increase lymph flow rate, 4 L of warm lactated Ringer's solution were infused intravenously into the fetus over 4 hours, because this causes mild edema as determined ultrasonographically. During a 1-hour preinfusion period lymph flow rate was 0.53 +/- 0.06 ml/min. During the infusion increases occurred in fetal arterial (7.6 +/- 1.0 mm Hg) and venous (2.4 +/- 0.3 mm Hg) pressures (p < 0.001). Lymph flow rate increased and reached a plateau after 1 hour at 339% +/- 30% of preinfusion values (p < 0.001). When the infusion was terminated, fetal arterial and venous pressures rapidly returned to preinfusion levels. Lymph flow rate gradually decreased during the first 30 minutes and stabilized at 97% +/- 17% above control during the subsequent 30 minutes. Analysis of lymph flow rate as a function of outflow pressure revealed that the increases in flow occurred because of an upward shift in the plateau flow rate with no change in the stop-flow pressure. (1) Fetal left thoracic duct lymph flow rate can increase significantly above basal values and therefore is an important safety factor against fetal edema formation. (2) The maximal lymph flow rate appears to be 3.4 times normal when venous pressure is elevated and two times normal when venous pressure is normal.

Increased lymphatic pumping ability in pregnant ewes

OBJECTIVE: Daily the lymphatic system returns several liters of fluid to the systemic circulation. Unlike blood, lymph is pumped against a pressure gradient. Because vessels in the systemic circulation are hyporesponsive to vasoconstrictor hormones during pregnancy, we decided to assess whether lymphatic pumping ability was decreased during pregnancy.STUDY DESIGN: Ten pregnant ewes were chronically catheterized in the left thoracic duct and jugular vein. Four days after surgery thoracic duct pumping ability was determined by measuring the lymph flow rate as a function of outflow pressure by varying the height at which lymph flow drains in an open-flow system.RESULTS: Lymph flow was plotted against outflow pressure, and the value at which lymph flow decreases is defined as the “breaking point.” The outflow pressure at which lymph flow equals zero is the “stopflow” pressure; this value defines the pumping ability. The pregnant ewes had a breaking point of -1 ± 2.7 versus 14.4 ± 3.0 mm Hg (mean ± SD) for the nonpregnant sheep. Stopflow pressures were 62 ± 7.3 versus 23.9 ± 4.7 mm Hg (mean ± SD) for the nonpregnant ewes (p \\lt 0.05).CONCLUSIONS: The ability of the lymphatic system to generate pressure is increased during pregnancy, but the breaking point is diminished. Alterations of lymphatic pumping ability could explain fluid retention under pathophysiologic conditions. (AM J OBSTET GYNECOL 1992;167:1756-9.)

Long-term vascular volume expansion maintains elevated thoracic duct lymph flow

OBJECTIVE: To investigate the mechanisms responsible for edema seen during pregnancy, we tested whether lymph vessels are able to pump high volumes over long periods of time. STUDY DESIGN: In six chronically catheterized nonpregnant ewes, we examined left thoracic duct lymph flow rate and fluid balance responses to the administration of a balanced isotonic solution at a rate of 1 L/hr for 20 hours. Because estrogen administration decreases lymphatic contractility against outflow pressure, we also administered conjugated estrogens (Premarin) during the last 3 hours of the fluid infusion (experimental time 17 to 20 hours). RESULTS: After volume loading for 16 hours, the mean ± SEM lymph flow rate, blood volume, and arterial pressure rose 100% ± 26%, 20% ± 2.3%, and 16% ± 8.1%, respectively. Vascular compliance decreased significantly and, as evidenced by a lack of body weight changes, interstitial fluid volume failed to change ( p < 0.05, analysis of variance). The transcapillary oncotic pressure difference increased by 2 mm Hg; venous pressure increased by 5.2 mm Hg. These data suggest that transcapillary forces favored fluid movement into the interstitium. Lymph flow rate remains elevated after blood volume expansion to a level similar to that described during pregnancy in sheep. A transient decrease in urinary output (∼20%) occurred with no changes in lymph flow rate, arterial pressure, or blood volume. CONCLUSION: Lymph flow rate is able to compensate for the increased capillary filtration observed during prolonged blood volume expansion.

Left thoracic duct lymph flow responses to angiotensin II or atrial natriuretic factor infusion in the ovine fetus

In the ovine fetus it is known that left thoracic duct lymph flow rate relative to body weight is four to five times adult levels, but it is not known whether the circulating hormones modulate fetal lymph flow. To explore this, we intravenously infused either angiotensin II (10 to 400 ng/min, n = 8) or atrial natriuretic factor (500 to 1000 ng/min, n = 8) into chronically catheterized fetal sheep for 30 minutes. Significant increases occurred in fetal arterial (p < 0.0001) and venous (p = 0.018) pressures during the angiotensin II infusion, and thoracic duct lymph flow rate underwent a dose-dependent increase (r = 0.888, p = 0.0033). With termination of the angiotensin II infusion, fetal vascular pressures rapidly returned to control levels, and lymph flow fell from 18.8% ± 10.1% (mean ± SE) above control to 13.7% ± 7.7% below preinfusion levels (p < 0.01 ). During the atrial natriuretic factor infusion, fetal arterial pressure and circulating blood volume decreased significantly (p < 0.01 ), whereas thoracic duct lymph flow was unchanged. After termination of the atrial natriuretic factor infusion, fetal arterial pressure returned toward control, blood volume remained reduced, and lymph flow rate underwent a transient rise to 35.6% ± 15.7% (p < 0.05) above control levels. These data suggest that angiotensin II and atrial natriuretic factor have significant but opposite effects on fetal thoracic duct lymph flow rate, with angiotensin II stimulating and atrial natriuretic factor suppressing lymph flow. (AM J OBSTET GYNECOL 1991;165:1607-13.)

Effects of outflow pressure and vascular volume loading on thoracic duct lymph flow in adult sheep

Studies have shown that lymph flow rate from several tissues depends on the pressure at the outflow end of the lymphatics. The left thoracic lymph duct is the largest lymphatic vessel and it transports a majority of the body's lymph. We varied outflow pressure for the left thoracic lymph duct independent of venous pressure in six unanesthetized, nonpregnant adult ewes with chronic lymphatic and venous catheters. When outflow pressure was negative, the thoracic duct lymph flow rate was independent of outflow pressure and averaged 0.040 +/- 0.004 (SE) ml.min-1.kg body wt-1. Lymph flow began to decrease with increasing outflow pressure only when outflow pressure was significantly greater than venous pressure. Above this breakpoint, lymph flow decreased linearly with outflow pressure and ceased at an outflow pressure of 25.6 +/- 4.2 mmHg. After vascular volume loading with lactated Ringer solution, steady-state thoracic duct lymph flow increased to 351 +/- 54% of control and was independent of outflow pressure when outflow pressure was negative. As outflow pressure was elevated, lymph flow began to decrease at the same breakpoint as before volume loading, and lymph flow ceased at the same outflow pressure as before volume loading. Thus this study shows that there is a plateau where thoracic duct lymph flow rate is independent of outflow pressure. In addition venous pressure under normal or volume-loaded conditions is not an impediment to thoracic duct lymph flow in unanesthetized sheep. Large increases in venous pressure are required to totally block thoracic duct lymph flow.

Effects of outflow pressure on fetal lymph flow

The purpose of this study was to determine to what extent fetal thoracic duct lymph flow may be reduced by increases in fetal venous pressure. In pregnant sheep the fetal left thoracic lymph duct was catheterized at the base of the neck and this catheter was connected to a jugular-vein catheter so the lymph could spontaneously return to the fetal circulation. At 5 days after catheter implantation in nine unanesthetized fetuses at 133 +/- 1 (SE) days' gestation, lymph flow was measured by disconnecting the lymphatic catheter from that in the jugular vein and varying outflow pressure of the lymphatic catheter independent of venous pressure. Whenever outflow pressure was negative, lymph flow was independent of outflow pressure and averaged 0.66 +/- 0.05 ml/min. When outflow pressure of the left thoracic duct was increased above zero, lymph flow decreased linearly with outflow pressure and flow stopped at an outflow pressure of 11.5 +/- 0.6 mm Hg. At a normal venous pressure of 3 mm Hg, the lymph-flow sensitivity to venous pressure was such that a 1 mm Hg rise in venous pressure reduced lymph flow by 12.7% +/- 1.2%. Thus it appears that fetal lymph flow is very sensitive to outflow pressure and only moderate elevations in venous pressure potentially may lead to fetal edema.

Pleural effusion complicating radical neck dissection

Three cases of the pleural effusion complicating radical neck dissection were reported and discussed.Radical neck dissection was performed on the left side neck and thoracic duct was injured intraoperatively in every 3 cases.In 2 cases, extra cellular Sudan III positive granules were found in pleural effusion. In 1 case, lymphangioscintigraphy showed accumulation of radio activity in the thoracic cavity.Therefore, pleural effusion seemed to be the accumulation of chyle or thoracic duct lymph.All 3 cases were healed by the conservative treatment without further complication.

Thoracic duct lymph flow and its measurement in chronically catheterized sheep fetus.

A method was developed for chronic catheterization of the left thoracic lymph duct at the base of the neck in the sheep fetus, which did not disrupt the other major lymphatic vessels that join the venous circulation at the same location. The lymphatic catheter was connected to a catheter in a jugular vein when lymph flow was not being recorded, so that the lymph continuously returned to the fetal circulation. Special consideration of catheter size to minimize flow resistance and treatment to prevent clotting were required. Individual animals were maintained up to 17 days with lymph flow continuing. In 13 fetuses averaging 128 days gestation (term = 147 days) at the time of catheterization, lymph flow rate was measured for 1 h each day for the first 7 postsurgical days with an on-line computer technique that continuously calculated lymph flow rate. Lymph flow averaged 0.64 +/- 0.17 (SD) ml/min in fetuses weighing 2.3-4 kg and tended to undergo a nonsignificant increase with time. Lymph and plasma protein concentrations did not change with time. In individual fetuses, large spontaneous variations in lymph flow rate occurred over periods of several seconds to a few minutes. Analysis showed that these variations in flow rate were not associated with fetal breathing movements. Thus the present study describes a technique for studying the dynamics of lymph flow in the unanesthetized sheep fetus in utero over a time period limited primarily by the length of gestation. In addition, it appears that thoracic duct lymph flow rate in the fetus per unit body weight averages three to four times that in the adult.

Fetal thoracic duct lymph flow response to intravascular saline infusion.

The left thoracic lymph duct was catheterized at the base of the neck in the sheep fetus at 123-136 days of gestation, and the lymphatic catheter was connected to a jugular vein catheter so that the lymph could return to the fetus. Lymph flow was studied 5 days after catheter implantation in the unanesthetized fetus. Basal fetal thoracic duct lymph flow rate per unit body weight averaged three times adult sheep values. After an infusion of 20 ml/kg of warmed isotonic saline into a fetal vein over 5 min, lymph flow rate increased significantly to 161 +/- 15% of control, with a peak at 8 min after termination of the infusion, and flow declined thereafter. The increased lymph volume above baseline values over 30 min averaged 5.7% of the infused volume and is similar to the adult response. Plasma and lymph protein concentrations decreased as did the lymph-to-plasma protein concentration ratio. The latter is opposite to what occurs in the adult under the same conditions. Thus the present study shows that even though the fetus has a much higher basal thoracic duct lymph flow rate than the adult, the responsiveness of the fetal lymphatic system to intravascularly infused saline is similar to that of the adult. The decrease in the lymph-to-plasma protein concentration ratio suggests that there may be differences between fetal and adult vascular-interstitial-lymphatic protein kinetics.

Lymphatic and vascular responses to fluid infusion in castrated and noncastrated sheep.

Estrogen administration produces blood volume expansion and interstitial fluid retention. We decided to study the effect of estrogen withdrawal on blood volume and determine whether oophorectomy has an effect on lymph flow or protein concentration. The rate of left thoracic duct lymph flow averaged 0.041 +/- 0.005 (SE) and 0.071 +/- 0.008 ml X min-1 X kg-1 in castrated (n = 9) and noncastrated (n = 9) female sheep, respectively (P = 0.006). After three serial intravenous infusions of Ringer lactate solution (2% body wt/infusion) the thoracic duct lymph flow in the castrated animals increased 358, 457, and 498% over the base-line rate, compared with increase of 200, 235, and 353% in the nonpregnant ewes. However, with the lower control values in the castrated animals, the lymph flow rate reached the same absolute values as those seen in the noncastrated ewes. Lymph protein concentration and the lymph-to-plasma protein concentration ratio, as well as arterial and venous pressures, were unaltered by oophorectomy. Base-line whole blood volumes were 58.2 +/- 1.9 (n = 9) and 64.8 +/- 2.6 ml/kg (n = 9) in the castrated and noncastrated ewes, respectively (P less than 0.05). Systemic vascular compliance averaged 4.5 +/- 0.7 and 7.1 +/- 1.7 ml X kg-1 X mmHg-1 in the castrated and noncastrated ewes, respectively (P less than 0.05), whereas interstitial fluid compliance values were 12 and 32 ml X kg-1 X mmHg-1, respectively. The capillary filtration coefficients were not different in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II infusion increases thoracic duct lymph flow in chronically catheterized sheep.

Both pregnancy and estrogen administration are associated with a decrease in the systemic vasculature pressor response to angiotensin II infusion; however, the lymphatic vessel system response is not clear. In the present study we infused angiotensin II to nine nonpregnant splenectomized ewes with 0.1, 10, or 1,000 ng X kg-1 X min-1 for a 5-min period at each dose. At the lowest dose the mean arterial pressure increased from 10 to 20% over base line. At the highest dose, the left thoracic duct flow rate peaked at 361% 10 min after the infusion was started, whereas arterial pressure peaked at 183% of the control value. Peak lymph flow occurred 4-6 min after the maximal increase in mean systemic arterial pressure. Neither hematocrit nor venous pressure were altered at any of the doses administered. This suggests that the interstitial fluid space pressure remained unchanged and that the increase in lymph flow was not secondary to fluid transfer from the intravascular system. We postulate, therefore, that the effect of angiotensin II in the increase of lymph flow rate is by direct action on the lymphatic vessels themselves.