SN was one of the first agents used for pleurodesis in concentrations varying from 1 to 10% and had a success rate of 75 to 90%. In a rabbit model with normal pleura, the intrapleural injection of 0.5% SN produced a pleurodesis similar to that produced by 35 mg/kg tetracycline and was superior to that induced by TL slurry, 400 mg/kg. Of concern was the possibility that, due to its intense local caustic effect, SN could produce lung damage. However, in a subsequent 1-year follow-up study, SN induced only minimal microscopic lung damage that decreased after 2 weeks, and was similar to that produced by TL after 21 days.
In the present study, the effects of the intrapleural injection of TL or SN on WBC count, neutrophil percentage, lactate dehydrogenase (LDH), interleukin (IL)-8, and vascular endothelial growth factor (VEGF) levels in the serum and the pleural fluid 6, 24, and 48 h after injection were studied. IL-8 was chosen because its role in pleural inflammation is well-established, and it is known that inflammatory stimuli, asbestos fibers, and infective agents stimulate significant increases in the production of IL-8 by the mesothelial cells. natural breast enhancement pill
VEGF was chosen because its levels are increased in exudative effusions, and it increases the vascular per-meability. We hypothesized that the intrapleural injection of TL and SN in doses sufficient to induce pleurodesis would induce an acute systemic inflammatory response.
Fifty-four white New Zealand male rabbits (nine groups of 6 rabbits) weighing 2.0 to 2.5 kg were subjected to an intrapleural injection of 3 mL saline solution, TL, 400 mg/kg (USP Pharmacy; Sao Paulo, Brazil), or 0.5% SN (Merck; Darmstadt, Germany). These doses were selected because they have been shown previously to induce pleurodesis in our experimental model in rabbits. Groups of six rabbits receiving each agent were killed after 6, 24, and 48 h. Briefly, the rabbits were anesthetized with ketamine hydrochloride, 35 mg/kg (Cristalia; Sao Paulo, Brazil), plus xylazine hydrochloride, 5 mg/kg (Bayer; Sao Paulo, Brazil), and had their right chests shaved and cleansed with povidone-iodine solution (Rioquimica; Sao Paulo, Brazil). A parasternal 2-cm chest incision was made, and a 21-gauge needle was inserted through the intercostal muscle for the injection of the solution into the pleural space. After the instillation, the muscle and skin were sutured with nylon 5- 0.