On the alteration of pulmonary arteries in different experimental pneumoconioses.

CFY rats were treated intratracheally on one occasion with 60 mg of DQ12 quartz, illite (aluminosilicate) and enargite (dead rocks of a metal mine) suspended in 1 ml physiological saline. After a year, the structure of the pulmonary arterial system of pneumoconiotic rats was investigated by means of injection-corrosion cast and gelatin-India ink samples in thick preparations. In the identically treated animals, blood-gas analysis was made of samples of femoral arteries before and after intravenous treatment with noradrenaline and acetylcholine (40-40 micrograms/b.w.) under sodium pentobarbital narcosis. It has been stated that in focal alterations characteristic of different types of pneumoconioses, arborisation of the pulmonary arteries is and a newly developed and/or transformed vascular structure can be observed around the foci. In pneumonoconiotic lungs, arteriovenous shunts are more frequent. The authors assumed some connection between the vascularization of foci and the progression of the fibrotic process: richer vascularization around and inside the foci was accompanied by significant fibrosis. The blood-gas values suggested compensated respiratory acidosis. In the examined pneumoconioses, the effect of vasoactive substances - in terms of blood-gas values - had not changed significantly.