Crosslinked Structure of Polyacrylic Acid Affects Pulmonary Fibrogenicity in Rats

• Published in: International journal of molecular sciences Vol. 23; no. 22; p. 13870
• Main Authors: Tomonaga, Taisuke, Nishida, Chinatsu, Izumi, Hiroto, Kawai, Naoki, Wang, Ke-Yong, Higashi, Hidenori, Takeshita, Jun-Ichi, Ono, Ryohei, Sumiya, Kazuki, Fujii, Shota, Hata, Yuki, Sakurai, Kazuo, Morimoto, Toshiki, Higashi, Yasuyuki, Yamasaki, Kei, Yatera, Kazuhiro, Morimoto, Yasuo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.11.2022; MDPI
• Subjects: Animals; Asbestos; Bronchoalveolar Lavage Fluid - chemistry; Cytokines; Gene expression; Inflammation; Lavage; Lung - pathology; Lung diseases; Lungs; Molecular weight; Neutrophils; Organic chemicals; Oxidative stress; Pathogenesis; Polymers; Proteins; Rats; Rats, Inbred F344; Rats, Wistar; Zinc oxides; Japan; polyacrylic acid (PAA); pulmonary toxicity; crosslinking; organic chemicals
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms232213870

We conducted intratracheal instillations of polyacrylic acid (PAA) with crosslinking and non-crosslinking into rats in order to examine what kinds of physicochemical characteristics of acrylic-acid-based polymers affect responses in the lung. F344 rats were intratracheally exposed to similar molecular weights of crosslinked PAA (CL-PAA) (degree of crosslinking: ~0.1%) and non-crosslinked PAA (Non-CL-PAA) at low and high doses. Rats were sacrificed at 3 days, 1 week, 1 month, 3 months, and 6 months post-exposure. Both PAAs caused increases in neutrophil influx, cytokine-induced neutrophil chemoattractants (CINC) in the bronchoalveolar lavage fluid (BALF), and heme oxygenase-1 (HO-1) in the lung tissue from 3 days to 6 months following instillation. The release of lactate dehydrogenase (LDH) activity in the BALF was higher in the CL-PAA-exposed groups. Histopathological findings of the lungs demonstrated that the extensive fibrotic changes caused by CL-PAA were also greater than those in exposure to the Non-CL- PAA during the observation period. CL-PAA has more fibrogenicity of the lung, suggesting that crosslinking may be one of the physicochemical characteristic factors of PAA-induced lung disorder.