[An experimental study on pulmonary vascular inflammation in a rat model of chronic bronchitis and emphysema].

OBJECTIVE

To study the characteristics of intra-acinar pulmonary artery inflammation in rats with chronic bronchitis (CB) and emphysema and to evaluate the protective and therapeutic effects of erythromycin (EM).

METHODS

Eighteen male Wistar rats were divided into 3 groups randomly, 6 rats per group, a normal control group (group A), a CB and emphysema group (group B), and an EM-treatment group (group C). The rat model of CB and emphysema was established by intratracheal instillation of lipopolysaccharide (LPS) and daily exposure to cigarette smoke. After 8 weeks the pathological and morphometric changes in the lung were analyzed.

RESULTS

(1) The inflammation in intra-acinar pulmonary arteries, described as total inflammatory cells per square millimeter of adventitia (cell/mm(2)), was different among the three groups, (33 +/- 6) cell/mm(2) in group A, (158 +/- 68) cell/mm(2) in group B, and (54 +/- 7) cell/mm(2) in group C; the difference being significant between group A and group B and between group B and group C (t = 9.6, 9.2, all P < 0.01). (2) The morphometric characteristics of intra-acinar pulmonary muscular arteries: the thickness of intra-acinar pulmonary muscular arteries, described as intimal area per total area, was significantly different among the groups (t = 9.7, 9.4, all P < 0.01), (21 +/- 4)% in group A, (37 +/- 3)% in group B, and (30 +/- 1)% in group C.

CONCLUSIONS

There was inflammatory reaction largely of lymphocyte infiltration in the adventitia of intra-acinar pulmonary arteries in rats with CB and emphysema. Inflammatory reaction in intra-acinar pulmonary arteries plays an important role in vascular remodeling. EM may prevent the inflammation and remodeling of intra-acinar pulmonary arteries to some degree.