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In order to study the effects of 1-(2, 6-dimethylphenoxy)-2-(3, 4-dimethoxyphenylethylamino) propane hydrochloride (DDPH) on proliferation and immunophenotypes of newborn rat pulmonary vascular pericytes induced by hypoxic endothelial cell conditioned medium (HECCM) from porcine pulmonary arteries, the cultured pericytes were divided into 4 groups according to the endothelial cell conditioned medium (ECCM) used: normoxic ECCM (NECCM) group, NECCM + DDPH group, HECCM group and HECCM + DDPH group. Cell culture, immunocytochemical staining, image analysis and flow cytometric method were used to investigate the effects of HECCM and DDPH on the expression of alpha-smooth muscle actin (alpha-SM-Actin) antigen, CD34 antigen, S-100 antigen and proliferating cell nuclear antigen (PCNA) and cell cycle in pericytes. The results showed that the alpha-SM-Actin antigen in the pericytes in HECCM group was stronger positively expressed than in the other three groups, but CD34 antigen and S-100 antigen were negatively expressed. The expression of alpha-SM-Actin antigen, CD34 antigen and S-100 antigen was positive in the groups of NECCM, NECCM + DDPH and HECCM + DDPH; The expression of alpha-SM-Actin and PCNA in HECCM group was 1.32 times (P0.01) and 1.24 times (P0.05) that in NECCM group, 1.30 times (P0.01) and 1.21 times (P0.05) that in HECCM + DDPH group, respectively. The percentage of the cells in the GO-G1 phase in the HECCM group was lower by 11.7% and 9.1%, in S phase higher by 5.6% and 4.2%, in G2-M phase higher by 6.1% and 4.9% than in the groups of NECCM, HECCM + DDPH, respectively. The inhibitory rate of DDPH on the increased alpha-SM-Actin and PCNA syntheses in pericytes induced by HECCM were 23.4% and 17.1% respectively. The inhibitory rate on the increased pericytes from GO-G1 phase to S phase was 8.3%. These results suggest that DDPH can directly inhibit pericytes from proliferation and immunophenotypical transformation of smooth muscle-like cells induced by HECCM.

In order to study the cellular origin of muscularization in non-muscular arterioles of the lung, the pulmonary vascular pericytes-culture was established. The terminal lung tissue of the rat was taken out and minced. Then 0.5% of type IV collagenase solution was added for digestion and the microvascular segments were obtained by screening. The targeted cells were cultured by "selective conditioned media". Under phase-contrast microscope, the cultured cells were large in size with ragged margin and numerous pseudopodia, which imparted tubule-like structure. There was no contact inhibition in growing cells, so multiple layers developed. When they were confluent, there were morphologically no "hillock and dale" growth pattern as in smooth muscle cells or "weave-like" pattern as in fibroblasts. The ultrastructure of cultured cells showed numerous digital processes, moderate amount of rough and smooth endoplasmic reticulum, rich Golgi's apparatus, microfilaments, few lysosomes without myofilaments and dense bodies. Immunohistochemical staining revealed that the cultured pericytes had same kind of cellular skeletal protein, alpha-SM-actin, like smooth muscle cells. The cultured cells also exhibited positive reaction to CD34 antigen and S-100 antigen, which were negative in smooth muscle cells and fibroblasts. The cell growth pattern, ultrastructure and immunological phenotype suggested that the cultured cells had characteristics of vascular pericytes. Pericytes are one of the components of microvascular cells, and the establishment of in vitro culture technique of pericytes is of significance for further exploration of the muscularization of non-muscular arterioles in lung and the mechanism of structural remodeling of pulmonary vessels.

The pulmonary arteriole remodeling in Wistar rats with respiratory infection induced by mycoplasma pneumoniae was observed using light microscopy and morphometry. The pulmonary artery pressure (PAP) and index of right ventricular hypertrophy (RVHI) were measured. The intimal and medial hypertrophy can be seen in the pulmonary arterioles, leading to vessel wall thickening and narrowing of the lumina. The total number of the pulmonary arterioles decreased (P0.01), and both pulmonary hypertension (Ppa 4.11 +/- 0.19 kPa) and right ventricular hypertrophy (RVHI = 34.96 +/- 3.91%) occurred. In addition, an interstitial pulmonary fibrosis (IPF) was found, in which the content of collagen in the lung tissue changed, i. e., type I collagen increased whereas type III one decreased, and the ratio of type I collagen to type III one increased. It suggested that respiratory infection induced by repeated MP may result in remodeling of pulmonary arterioles and are closely related to pulmonary hypertension.

The inhibitory effect of Radix Salviae Miltiorrhizae (RSM) on hypoxic structural remodeling of intra-acinar pulmonary arteries (IAPA) was observed by light and electron microscopy and morphometry. It was found that RSM can not only dilate IAPA and relieve the hypoxic injuries to endothelia cells, but also inhibit the active muscularization of IAPA in the hypoxic animals, suggesting that RSM plays a very important role in inhibiting structural remodeling of IAPA and pulmonary hypertension.

The monocrofaline-induced structural changes of small pulmonary arteries in rat and their relationship with pulmonary hypertension and right ventricular hypertrophy were observed by determining the right ventricular systolic pressure, and by light and electron microscope and morphometry. One to 38 days after last injection of monocrotaline (MCT), a medial thickening and lumen marrrowing of the circular muscular arteries (CMA), accompanying terminal (TB) and respiratory bronchioles (RB), were found. And there after the lumen of CMA, accompanying TB, became dilated, and its medial thickness (MT) decreased, whereas the histopathologic changes of the partially muscular arteries (PMA), accompanying RB, became severe, their MT increased continuously, and finally reached the peak value on Day 50. At the first day after last MCT treatment, inflammation and muscularization were found in PMA and nonmuscular arteries (NMA), and became more severe with the cause of disease. Therefore, the intra-acinar pulmonary arteries, both CMA and PMA, increased in number while the NMA decreased in number significantly because of the structural remodeling. Four days after MCT treatment, the right ventricular systolic pressure began to rise, and reached its peak value on Day 50. Eight days after MCT injection, right ventricular hypertrophy developed, and became most significant from Day 23 to Day 30. The results suggest that structural remodeling, i.e. muscularization, of intra-acinar pulmonary arteries plays an important role in the development of pulmonary hypertension and right ventricular hypertrophy.

The changes in small pulmonary arteries of 15 patients with chronic obstructive pulmonary disease (COPD) were investigated by light and electron microscopy, image analysis etc. It was found that the structural changes in the pulmonary arteries of the patients with COPD were characterized by muscularization of non-muscular arterioles, media hypertrophy, longitudinal smooth muscle bundles in the intima and fibrosis in both the media and intima. In the course of time, these lesions resulted in thickening of the arterial wall and narrowing of the lumen. Clinically, the patients developed pulmonary hypertension causing cor pulmonale. Initial data on the structure of arterial wall at different segments were compared statistically. There was very significant difference between the COPD and control groups (P less than 0.001). By Fisher's auto-classification (automatic pattern recognition), the rate recognized was correct in more than 90% in the small arteries of less than 200 microns in diameter. It is suggested that these arteriolar changes are closely related to pulmonary hypertension. The image analysis showed that the ratios of MWA/MVA and MWT/MD were of great value in evaluating the degree of the changes in the arteries of the patients with COPD.

Rabbits and rats were infected intratracheally with extracellular enzyme of Streptomyces thermohygroscopicus (H9-4) by only one exposure, and lesions of the lung developed including mononuclear macrophage infiltration as well as bronchitis and vasculitis. The obvious damages in type I pneumocytes, endothelial cells of capillaries and arterioles in the lung were observed by electron microscopy. Immunofluorescent histochemistry examination revealed exudation of plasma fibronectin which might play an important role during the process of lesion repairing in lung. The experiment also confirmed that extracellular enzyme of Streptomyces thermohygroscopicus might directly damage the lung tissue. These experimental data may serve as valuable reference for studying the etiology and pathogenesis of farmer's lung disease.

Whether or not the pericytes exist in the intra-acinar pulmonary arteries and their normal structure and morphological changes during development of the structural remodeling of pulmonary vessels were observed using a pulmonary hypertension model in rats induced by monocrotaline injection. The results showed that the pericytes in the peripheral pulmonary vessels proliferated and transformed into smooth muscle cells during development of pulmonary hypertension, and at the same time, the pericytes could synthesize and secrete extracellular matrix including collagen, suggesting that the pericytes play an important role in the development of pulmonary hypertension and structural remodeling of the pulmonary vessels.

To study the effect of c-myc antisense oligodeoxynucleotides (ODNs) on proliferation of pulmonary vascular pericytes (PC) induced by hypoxia, cell culture, dot hybridization using probe of digoxigenin-11-dUTP-labeled cDNA,3H-thymidine incorporation, immunocytochemical technique and image analysis methods were used to observe the effect of c-myc antisense ODNs on expression of c-myc gene and proliferating cell nuclear antigen (PCNA), and3H-thymidine incorporation of PC induced by hypoxia. The results showed that hypoxia could significantly enhance the expression of cmyc and PCNA (P < 0.01), and elevate3H-thymidine incorporation of PC (P < 0.01), but antisense ODNs could significantly inhibit the expression of c-myc and PCNA (P < 0.05), and3Hthymidine incorporation of PC (P < 0.01). It was suggested that hypoxia could promote the proliferation of PC by up-regulating the expression of c-myc gene, but c-myc antisense ODNs could inhibit hypoxia-induced proliferation of PC by downregulating the expression of c-myc gene.

The effects of the medium conditioned by endothelial cells under hypoxic condition on the phenotype modulation of pulmonary artery smooth muscle cells (PASMCs) were investigated by using cell culture and morphometrical analysis. The results showed that the number of diploid cells and alpha-sm-actin of PASMCs in the hypoxic endothelial cell conditioned medium group (HECCM) was lower and the myofibrilles were even less than that in normal endothelial cell conditioned medium group (NECCM). On the contrary, the volume density of rough endoplasmic reticulum (RER) and mitochondria of PASMCs in the HECCM group was higher than that in the NECCM group, i. e. altering from a contractile type to a synthetic type. However, under direct hypoxic condition for 24 h, the phenotype of cultured PASMCs remained unchanged, i. e. retained contractile type. It suggests that the HECCM can induce phenotype modulation of PASMCs, may be mediated by the pulmonary artery endothelial cells (PAECs) which can secrete some cytokins affecting the PASMCs.