A reduction in diaphragm mobility has been identified in patients with chronic obstructive pulmonary disease (COPD) and has been associated with a decline in pulmonary function parameters. However, little information exists regarding the potential role of diaphragm mobility on hypercapnia in COPD. A new method of assessing the mobility of the diaphragm, using ultrasound, has recently been validated. The purpose of the present study was to investigate the relationship between diaphragm mobility and pulmonary function parameters, as well as that between arterial blood gas values and diaphragm mobility, in COPD patients. Thirty seven COPD patients were recruited for pulmonary function test, arterial blood gas analysis and diaphragm mobility using ultrasound to measure the craniocaudal displacement of the left branch of the portal vein. There were significant negative correlations between diaphragmatic mobility and PaCO2 (r = -0.373, P = 0.030). Diaphragmatic mobility correlated with airway obstruction (FEV1, r = 0.415, P = 0.011) and with ventilatory capacity (FVC, r = 0.302, P = 0.029; MVV, r = 0.481, P = 0.003). Diaphragmatic mobility also correlated significantly with pulmonary hyperinflation. No relationship was observed between diaphragm mobility and PaO2 (r = -0.028, P = 0.873). These findings support a possibility that the reduction in diaphragm mobility relates to hypercapnia in COPD patients.
Aged ; Airway Resistance/physiology ; Carbon Dioxide/blood/physiology ; Diaphragm/physiopathology/*ultrasonography ; Female ; Humans ; Hypercapnia/complications/*physiopathology ; Male ; Middle Aged ; Portal Vein ; Pulmonary Disease, Chronic Obstructive/complications/*physiopathology/ultrasonography ; Pulmonary Gas Exchange ; Respiratory Muscles/physiopathology

OBJECTIVETo study the effect and mechanism of chimonin on pulmonary arterioles I and III type collagen metabolism in pulmonary hypertension rats induced by chronic hypoxic hypercapnia.

METHODSThirty-six Sprague-Dawley rats were randomly divided into three groups: normal control group(A), hypoxic hypercapnic group(B), hypoxic hypercapnia + chimonin group(C). Collagen I, III and their mRNA, Blood CO concentration (COHb%), activity of HO-1 in blood serum and lung homogenate, content of hydroxyproline in lung homogenate, pulmonary arteriole micromorphometric index were observed.

RESULTSHypoxic hypercapnic rats's mPAP, Hyr of lung homogenate, content of I type collagen and I type collagen mRNA in pulmonary arterioles, were significantly higher than those in control group, pulmonary vessel remodeling of hypoxic hypercapnic rats was significant, those changes in hypercapnia + chimonin group were significantly lower than those in hypoxic hypercapnic group. Blood CO concentration, activity of HO-1 in blood serum and lung homogenate in rats of hypoxic hypercapnic rats were significantly higher than those of control group, and those of hypercapnia + chimonin group were even higher than hypoxic hypercapnic group (P < 0.01). There was no significant difference in mCAP, content of III type collagen and their mRNA in three groups (P > 0.05).

CONCLUSIONChimonin can reduce pulmonary hypertension and pulmonary vessel remodeling induced by hypoxic hypercapnia through inhibiting proliferation of collagen I, the mechanism maybe is up regulating endogenous carbon monoxide system.

Animals ; Arterioles ; metabolism ; Carbon Monoxide ; metabolism ; Chronic Disease ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Hypercapnia ; complications ; physiopathology ; Hypertension, Pulmonary ; etiology ; metabolism ; physiopathology ; Hypoxia ; complications ; physiopathology ; Lung ; blood supply ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the changes of the endogenous hydrogen sulfide(H2S) system in pulmonary hypertension induced by hypoxic hypercapnia (HHPH) in rats and approach the possible mechanisms.

METHODS20 SD rats were randomly divided into control group (C) and hypoxic hypercapnia group (HH) (n=10). The changes of hemodynamics and the right ventricle/left ventricle + septum (RV/LV + SP) were measured. The ratio of vessel wall area and total area (WA/TA) of arteriae pulmonalis were observed under lightmicroscope. By using TdT-mediated dUTP nick end labeling (TUNEL) and immunocytochemistry techniques, apoptosis index (AI) and expression of Bcl-2, Bax protein in arteriae pulmonalis were tested. Plasma level of H2S and activity of H2S generating enzymes in homogenates of rat lung tissue were evaluated by sensitive modified sulfide electrode method. Cystathionine-gamma-lyase (CSE) mRNA in lung tissues was determined by RT-PCR.

RESULTSThe level of mean pulmonary arterial pressure(mPAP), WA/TA and RV/LV + SP were significantly higher in HH group than those in C group (P < 0.05 or P < 0.01). Compared with those in C group, the AI of arteriae pulmonalis in HH group were significantly lower; the expression of Bcl-2 protein increased while that of Bax protein decreased, and the ratio of Bax/Bcl-2 went up obviously (all P < 0.01). Plasma level of H2S, the activity of H2S generating enzymes and CSE mRNA in HH group were significantly lower than those in C group (all P < 0.01). Plasma level of H2S, the activity of H2S generating enzymes, CSE mRNA each was closely positively related to Al while inversely related to mPAP and Bcl-2/Bax (all P < 0.01).

CONCLUSIONThe endogenous hydrogen sulfide system is closely related to pulmonary hypertension induced by hypoxic hypercapnia. The depression of the H2S/CSE system in HHPH may help increase the ratio of Bcl-2/Bax, inhibit apoptosis of pulmonary artery smooth muscle cells and finally result in the formation of pulmonary hypertension.

Animals ; Apoptosis ; physiology ; Hydrogen Sulfide ; metabolism ; Hypercapnia ; complications ; physiopathology ; Hypertension, Pulmonary ; etiology ; physiopathology ; Hypoxia ; complications ; physiopathology ; Male ; Muscle, Smooth, Vascular ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Rats ; Rats, Sprague-Dawley ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo investigate the changes of endoplasmic reticulum stress-induced apoptosis in pulmonary tissue of rats with hypoxic pulmonary hypertension.

METHODSTwenty two male SD rats were randomly divided into control group and 4-week hypoxia-hypercapnia group (n=11). The mean pulmonary arterial pressure (mPAP) and the mean carotid arterial pressure (mCAP) were monitored, and the weight ratio of right ventricle (RV) to left ventricle plus septum (LV + S) were measured. The rattish pathological model were assessed by mPAP, mCAP, RV/(LV+ S), vessel wall area/total area (WA/TA), vessel cavity area/total area (CA/TA) and media thickness of pulmonary arteriole (PAMT). The pulmonary apoptotic cells were detected by Hoechst staining. RT-PCR was used to study the genetic expression of caspasel2, glucose regulated protein 78 (GRP78) and GRP94 in pulmonary tissue. The expression of GRP94 and GRP78 proteins in pulmonary tissue were determined by using immunohistochemistry.

RESULTS(1) (The mPAP, RV/(LV + S), WA/TA and PAMT were respectively higher by 50.5%, 37.3%, 72.5% and 137% in hypoxic group than those in control group, while CA/TA was lower by 41.9% (all P < 0.01). There was not significant difference of mCAP between the two groups. (2) Hoechst staining showed that the pulmonary apoptotic cells in hypoxic group outnumbered markedly than those in control group, and the apoptotic cells were mainly in pulmonary tissue, while they were rare in pulmonary vascular smooth muscle cell. (3) Compared with control group, the expression of pulmonary caspasel2, GRP78 and GRP94 mRNA in hypoxic group were higher by 144%, 137% and 80.7% (all P < 0.05), respectively. (4) The expression of pulmonary GRP78 and GRP94 proteins were up-regulated in hypoxic group, and these proteins mainly localized in pulmonary vascular endothelial cell.

CONCLUSIONThe endoplasmic reticulum stress-induced apoptosis may be one of the mechanism of hypoxic pulmonary hypertension and pulmonary vascular wall remodeling.

Animals ; Apoptosis ; physiology ; Caspase 12 ; metabolism ; Endoplasmic Reticulum Stress ; physiology ; Heat-Shock Proteins ; metabolism ; Hypercapnia ; physiopathology ; Hypertension, Pulmonary ; etiology ; pathology ; physiopathology ; Hypoxia ; complications ; physiopathology ; Lung ; pathology ; Male ; Membrane Glycoproteins ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the effect of celecoxib on chronic hypoxia and hypercapnic pulmonary hypertension.

METHODSSD rats were randomly divided into normal control group (A), hypoxic hypercapnic group (B), hypoxic hypercapnia+ celecoxib group (C). The content of TXB2 and 6-keto-PGF1alpha in plasma and lung were detected by the technique of radioimmunology.

RESULTS(1) Mean pulmonary arteria pressure(mPAP) was significantly higher in rats of B group than those of A group. mPAP was significantly higher in rats of C group than those of B group. Differences of mPAP were not significant in three groups. (2) The content of TXB2 in plasma and lung and the ratio of TXB2/6-keto-PGF1alpha were significantly higher in rats of B group than those of A group. The ratio of TXB2/6-keto-PGF1alpha was significantly higher and the content of 6-keto-PGF1alpha in plasma and lung was significantly lower in rats of C group than those of B group. (3) Light microscopy showed that WA/TA (vessel wall area/total area) and PAMT (the thickness of medial smooth cell layer) were significantly higher in rats of B group than those of A group. WA/TA and PAMT were significantly higher in rats of C group than those of B group. (4) Electron microscopy showed the thickening of vessel wall and the proliferation of collagen fiber in B group and augmentation of smooth muscle cell and abundance of myofilament in pulmonary arterioles in C group.

CONCLUSIONCelecoxib can aggravate hypoxic hypercapnia pulmonary hypertension and pulmonary vessel remodeling by increasing the ratio of TXA2/PGI2.

Animals ; Celecoxib ; Chronic Disease ; Cyclooxygenase 2 Inhibitors ; adverse effects ; pharmacology ; Epoprostenol ; blood ; Hypercapnia ; complications ; Hypertension, Pulmonary ; etiology ; physiopathology ; Hypoxia ; complications ; Male ; Pyrazoles ; adverse effects ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Sulfonamides ; adverse effects ; pharmacology ; Thromboxane A2 ; blood

To investigate whether hypercapnic acidosis, induced by adding CO2 to inspired gas, would be protective effect against ventilator-induced lung injury (VILI), we ventilated 55 normal white rabbits for 6 hr or until PaO2/FIO2 <200 mmHg. Control group (n=15) was ventilated with peak inspiratory pressure (PIP) of 15 cm H2O, positive end-expiratory pressure (PEEP) of 3 cm H2O, an inspiration-to-expiration ratio of 1:2, and an inspired oxygen fraction (FIO2) of 0.40. High pressure hypercapnic group (HPHC; n=20) was ventilated with PIP of 30 cm H2O, PEEP of 0 cm H2O, and FIO2 of 0.40. Carbon dioxide was introduced into the inspiratory limb of the ventilator circuit, as necessary to maintain hypercapnia (PaCO2, 65 to 75 mmHg). High pressure normocapnic group (HPNC; n=20) was ventilated with same setting of HPHC, except normocapnia (PaCO2, 35 to 45 mmHg). Bronchoalveolar lavage fluid (BALF) lactate dehydrogenase, aspartate aminotransferase, interleukin-8 were significantly higher in high pressure ventilator group than control group (p<0.05). Wet weight to dry weight (WW/DW) and histologic scores were significantly higher in high pressure ventilator group than control group (p<0.05). However, there were no significant differences in oxygenation, BALF inflammatory markers, WW/DW and histologic scores between HPHC and HPNC groups. These findings suggest that hypercapnic acidosis at least induced by CO2 insufflation would not be protective effect against VILI in this model.
Acidosis, Respiratory/*chemically induced/complications/diagnosis/physiopathology ; Administration, Inhalation ; Animals ; Carbon Dioxide/*administration and dosage ; Hypercapnia/*chemically induced/complications/diagnosis/physiopathology ; Inhalation ; Pulmonary Gas Exchange ; Rabbits ; Research Support, Non-U.S. Gov't ; Respiration, Artificial/*adverse effects ; Respiratory Distress Syndrome, Adult/diagnosis/*etiology/physiopathology/*prevention and control ; Treatment Outcome