Intratracheal mesenchymal stem cell administration attenuates monocrotaline-induced pulmonary hypertension and endothelial dysfunction

2007 ◽  
Vol 292 (2) ◽  
pp. H1120-H1128 ◽  
Author(s):  
Syed R. Baber ◽  
Weiwen Deng ◽  
Ryan G. Master ◽  
Bruce A. Bunnell ◽  
Bradley K. Taylor ◽  
...  

The administration of mesenchymal stem cells (MSCs) has been proposed for the treatment of pulmonary hypertension. However, the effect of intratracheally administered MSCs on the pulmonary vascular bed in monocrotaline-treated rats has not been determined. In the present study, the effect of intratracheal administration of rat MSCs (rMSCs) on monocrotaline-induced pulmonary hypertension and impaired endothelium-dependent responses were investigated in the rat. Intravenous injection of monocrotaline increased pulmonary arterial pressure and vascular resistance and decreased pulmonary vascular responses to acetylcholine without altering responses to sodium nitroprusside and without altering systemic responses to the vasodilator agents when responses were evaluated at 5 wk. The intratracheal injection of 3 × 106 rMSCs 2 wk after administration of monocrotaline attenuated the rise in pulmonary arterial pressure and pulmonary vascular resistance and restored pulmonary responses to acetylcholine toward values measured in control rats. Treatment with rMSCs decreased the right ventricular hypertrophy induced by monocrotaline. Immunohistochemical studies showed widespread distribution of lacZ-labeled rMSCs in lung parenchyma surrounding airways in monocrotaline-treated rats. Immunofluorescence studies revealed that transplanted rMSCs retained expression of von Willebrand factor and smooth muscle actin markers specific for endothelial and smooth muscle phenotypes. However, immunolabeled cells were not detected in the wall of pulmonary vessels. These data suggest that the decrease in pulmonary vascular resistance and improvement in response to acetylcholine an endothelium-dependent vasodilator in monocrotaline-treated rats may result from a paracrine effect of the transplanted rMSCs in lung parenchyma, which improves vascular endothelial function in the monocrotaline-injured lung.

1993 ◽  
Vol 74 (2) ◽  
pp. 916-921 ◽  
Author(s):  
B. T. Thompson ◽  
D. M. Steigman ◽  
C. L. Spence ◽  
S. P. Janssens ◽  
C. A. Hales

Chronic hypoxia [inspiratory PO2 (PIO2) = 76 Torr for 10 days] produces pulmonary hypertension and vascular remodeling in the guinea pig. Increasing the duration of hypoxia from 10 to 21 days does not increase further pulmonary arterial pressure or medial thickening. To see if increasing severity of hypoxia affects the magnitude of pulmonary hypertension and remodeling, we exposed three groups of male Hartley guinea pigs to three levels of normobaric hypoxia for 10 days: PIO2 = 90 (n = 6), 78 (n = 6), and 65 Torr (n = 5). Pulmonary arterial pressure increased from 14 +/- 1 (+/- SE, n = 7) in room air to 23 +/- 3 mmHg when PIO2 = 90 Torr (P < 0.05). Pulmonary arterial pressure was slightly higher when PIO2 = 78 or 65 Torr (25 +/- 1 and 26 +/- 1 mmHg, respectively) but did not reach statistical significance vs. PIO2 = 90 Torr. Total pulmonary vascular resistance increased from 0.049 +/- 0.004 in room air to between 0.084 +/- 0.006 and 0.101 +/- 0.003 mmHg.min.kg.ml-1 (P < 0.05) in the three hypoxic groups; again there was no difference in total pulmonary vascular resistance among hypoxic groups. Medial thickness of alveolar duct and terminal bronchiole arteries increased with hypoxia, but there was no significant difference among the hypoxic groups. The percentage of intra-acinar vessels with thick walls (a measure of muscular extension) increased when PIO2 = 78 Torr and nearly doubled when PIO2 = 65 Torr in comparison to control.(ABSTRACT TRUNCATED AT 250 WORDS)


1999 ◽  
Vol 277 (3) ◽  
pp. L449-L456 ◽  
Author(s):  
Candice D. Fike ◽  
Mark R. Kaplowitz

Therapies to prevent the onset or progression of pulmonary hypertension in newborns have received little study compared with those in adult models. We wanted to determine whether nifedipine treatment prevents the increased pulmonary vascular resistance, blunted pulmonary vascular responses to acetylcholine, and reduced lung endothelial nitric oxide synthase (eNOS) amounts that we have found in a newborn model of chronic hypoxia-induced pulmonary hypertension. Studies were performed with 1- to 3-day-old piglets raised in room air (control) or 10% O2 (hypoxia) for 10–12 days. Some piglets from each group were given nifedipine (3–5 mg/kg sublingually three times a day). Pulmonary arterial pressure, pulmonary wedge pressure, and cardiac output were measured in anesthetized animals. Pulmonary vascular responses to acetylcholine and eNOS amounts were assessed in excised lungs. The calculated value of the pulmonary vascular resistance for nifedipine-treated hypoxic piglets (0.09 ± 0.01 cmH2O ⋅ ml−1 ⋅ min ⋅ kg) was almost one-half of the value for untreated hypoxic piglets (0.16 ± 0.01 cmH2O ⋅ ml−1 ⋅ min ⋅ kg) and did not differ from the value for untreated control piglets (0.05 ± 0.01 cmH2O ⋅ ml−1 ⋅ min ⋅ kg). Pulmonary arterial pressure responses to acetylcholine and whole lung homogenate eNOS amounts were less for both nifedipine-treated and untreated hypoxic piglets than for untreated control piglets. Nifedipine treatment attenuated pulmonary hypertension in chronically hypoxic newborn piglets despite the persistence of blunted responses to acetylcholine and reduced lung eNOS amounts.


Respiration ◽  
2000 ◽  
Vol 67 (5) ◽  
pp. 502-506 ◽  
Author(s):  
Akira Nakamura ◽  
Norio Kasamatsu ◽  
Ikko Hashizume ◽  
Takushi Shirai ◽  
Suguru Hanzawa ◽  
...  

1983 ◽  
Vol 55 (2) ◽  
pp. 558-561 ◽  
Author(s):  
J. Lindenfeld ◽  
J. T. Reeves ◽  
L. D. Horwitz

In resting conscious dogs, administration of cyclooxygenase inhibitors results in modest increases in pulmonary arterial pressure and pulmonary vascular resistance, suggesting that vasodilator prostaglandins play a role in maintaining the low vascular resistance in the pulmonary bed. To assess the role of these vasodilator prostaglandins on pulmonary vascular resistance during exercise, we studied seven mongrel dogs at rest and during exercise before and after intravenous meclofenamate (5 mg/kg). Following meclofenamate, pulmonary vascular resistance rose both at rest (250 24 vs. 300 +/- 27 dyn . s . cm-5, P less than 0.01) and with exercise (190 +/- 9 vs. 210 +/- 12 dyn . s . cm-5, P less than 0.05). Systemic vascular resistance rose slightly following meclofenamate both at rest and during exercise. There were no changes in cardiac output. The effects of cyclooxygenase inhibition, although significant, were less during exercise than at rest. This suggests that the normal fall in pulmonary vascular resistance during exercise depends largely on factors other than vasodilator prostaglandins.


1992 ◽  
Vol 73 (4) ◽  
pp. 1474-1480 ◽  
Author(s):  
C. M. Tseng ◽  
S. Qian ◽  
W. Mitzner

Changes in pulmonary hemodynamics and vascular reactivity in emphysematous hamsters were studied in an isolated lung preparation perfused at constant flow with blood and 3% dextran. Hamsters were treated with intratracheal porcine pancreatic elastase at 70 days of age, and experimental studies were conducted at 1, 3, and 8 mo after treatment. Baseline pulmonary arterial pressure in elastase-treated lungs was increased compared with saline-treated control lungs 1 mo after treatment, but this increase did not progress at 3 and 8 mo. Increases in pulmonary arterial pressure in elastase-treated lungs were temporally correlated with the morphological development of emphysema and right ventricular hypertrophy; both of these were evident at 1 mo after treatment and showed little change thereafter. Pressor responses to hypoxia and angiotensin II were not different between elastase-treated and control lungs at 1 and 3 mo. At 8 mo, however, pressor responses in emphysematous lungs to 0% O2 (but not to angiotensin II) were significantly increased. This was the result of a lack of the normal age-related fall in the hypoxic pressor response. Our results suggest that the right ventricular hypertrophy found in these emphysematous animals results from a chronically increased pulmonary vascular resistance. Furthermore, increases in pulmonary vascular resistance in the early development of emphysema are likely a result of the loss of vascular beds and supporting connective tissue.


1980 ◽  
Vol 239 (3) ◽  
pp. H297-H301 ◽  
Author(s):  
L. G. Moore ◽  
J. T. Reeves

Pregnancy decreases systemic vascular reactivity but comparatively little is known about the effects of pregnancy on the pulmonary circulation. Pulmonary vascular resistance (PVR) during acute hypoxia was lower (P < 0.01) in eight intact anesthetized pregnant dogs compared to the same animals postpartum. Mean pulmonary arterial pressure (Ppa) and PVR during infusion of prostaglandin (PG) F2 alpha were also reduced during pregnancy. Nonpregnant female dogs (n = 5) treated with estrogen (0.001 mg x kg-1 x da-1) for 2 wk had decreased Ppa (P < 0.01) during acute hypoxia compared to control measurements, but PVR was unchanged during hypoxia and PGF2 alpha infusion. Treatment with progesterone in four dogs had no effect on pulmonary vascular reactivity to hypoxia or PGF2 alpha. Inhibition of circulating PG with meclofenamate in four dogs during pregnancy did not appear to restore pulmonary vascular reactivity. Blunted pulmonary vascular reactivity is suggested by the limited data available for women, but is not seen in pregnant cows. We conclude that pregnancy decreases pulmonary as well as systemic vascular reactivity in the dog, but the mechanism is unclear.


1994 ◽  
Vol 77 (3) ◽  
pp. 1333-1340 ◽  
Author(s):  
K. Kubo ◽  
T. Kobayashi ◽  
T. Hayano ◽  
T. Koizumi ◽  
T. Honda ◽  
...  

The purpose of the present study was to assess the role of polymorphonuclear leukocyte (neutrophil) elastase in endotoxin-induced acute lung injury in sheep with lung lymph fistula. We studied the effects of ONO-5046, a specific inhibitor of neutrophil elastase, on the lung dysfunction induced by the intravenous infusion of 1 microgram/kg of Escherichia coli endotoxin. Endotoxin alone produced a biphasic response as previously reported. Early (0.5–1 h) after endotoxin, pulmonary arterial pressure increased from 19.5 +/- 0.9 cmH2O at baseline to a peak of 46.8 +/- 2.4 cmH2O (P > 0.05). Pulmonary vascular resistance increased from 3.03 +/- 0.17 cmH2O.l–1.min at baseline to a peak of 9.77 +/- 0.70 cmH2O.l–1.min (P < 0.05). Circulating neutrophils decreased from 7,355 +/- 434/mm3 at baseline to a nadir of 1,762 +/- 32/mm3 (P < 0.05). Thromboxane B2 and 6-ketoprostaglandin F1 alpha concentrations in plasma and lung lymph were significantly increased. Late (3–5 h) after endotoxin, pulmonary arterial pressure and pulmonary vascular resistance returned to baseline levels, but lung lymph flow remained increased from 4.2 +/- 0.3 ml/0.5 h at baseline to 7.3 +/- 0.7 ml/0.5 h (P < 0.05), with a slight increase in lung lymph-to-plasma protein concentration ratio, suggesting increased pulmonary vascular permeability. The histopathological features of the lungs during the early period in sheep treated with endotoxin alone revealed a large increase in neutrophils per 100 alveoli and changes of pulmonary edema such as thickening of the interstitium of the lung and alveolar flooding.(ABSTRACT TRUNCATED AT 250 WORDS)


1956 ◽  
Vol 186 (1) ◽  
pp. 74-78 ◽  
Author(s):  
E. D. Frank ◽  
H. A. Frank ◽  
S. Jacob ◽  
H. A. E. Weizel ◽  
H. Korman ◽  
...  

Norepinephrine infusion did not prolong the survival or effect the recovery of dogs in hemorrhagic shock unresponsive to replacement transfusion. During its pressor action in shock, either before or after replacement transfusion, norepinephrine infusion increased coronary, cerebral and adrenal blood flow, reduced renal blood flow, and did not change hepatic blood flow. Cardiac output was increased in oligemic shock but not after blood replacement. Pulmonary arterial pressure and right and left auricular pressures were raised by norepinephrine infusion in all phases of hemorrhagic shock, and calculated pulmonary vascular resistance was reduced.


1994 ◽  
Vol 76 (4) ◽  
pp. 1794-1801 ◽  
Author(s):  
T. D. Jacob ◽  
D. K. Nakayama ◽  
I. Seki ◽  
R. Exler ◽  
J. R. Lancaster ◽  
...  

We describe the hemodynamic effects and metabolic fate of inhaled NO gas in 12 anesthetized piglets. Pulmonary and systemic hemodynamic responses to incremental [NO] (5–80 ppm) were tested during ventilation with high- [0.30 inspired O2 fraction (FIO2)] and low-O2 (0.10 FIO2) mixtures. In six animals, inhalation of 40 ppm NO was maintained over 6 h to test effects of prolonged exposure (0.30 FIO2). In the other six animals, pulmonary hypertension was induced by hypoxic ventilation (0.10 FIO2) and responses to NO were tested. Inhaled low [NO] partially reversed pulmonary hypertension induced by alveolar hypoxia; mean pulmonary arterial pressure decreased from 31.4 +/- 2.3 mmHg during hypoxia to 18.2 +/- 1.2 mmHg during 5 ppm NO. Mean pulmonary arterial pressure at 0.10 FIO2 did not fall further at higher [NO] (10–40 ppm) and never reached control levels. Pulmonary vascular resistance increased with institution of hypoxic ventilation and fell with subsequent administration of NO, ultimately reaching control levels. Inhaled NO did not affect systemic vascular resistance. Plasma levels of NO2- + NO3- and methemoglobin (MetHb) levels increased with increasing [NO]. Over 6 h of NO administration during high-O2 ventilation, MetHb equilibrated at subtoxic levels while NO2- + NO3- increased. Nitrosylhemoglobin, analyzed by electron paramagnetic resonance spectrophotometry was not detected in blood at any time. At the relatively low concentrations (5–80 ppm) that are effective in relieving experimental pulmonary hypertension induced by alveolar hypoxia, inhaled NO gas causes accumulation of NO2- + NO3- in plasma and a small increase in MetHb but no detectable nitrosylhemoglobin.


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