Newborn sprague dawley rats

Newborn Sprague–Dawley rats (Charles River, St-Constant, QC, Canada) were placed under an oxygen concentration protocol cycling between 50 ± 1 and 10 ± 1% every 24 h from postnatal day (P) 0 to P14 (OIR/ROP) (Penn et al., 1994 (link)). On P14 rats were returned to room air. This model is characterized by retinal vascular decay (Penn et al., 1994 (link); Rivera et al., 2017 (link)) followed by hypoxia-driven inner retinal neovascularization which develops between P14 and P18. Control rats (NOR) were maintained in room air (21% O₂). Rats (n = 4/group), exposed or not to OIR, were randomly assigned to receive from P0 to P14 either twice-daily intraperitoneal injections of rytvela [1 mg/kg; custom synthesized by Elim Pharmaceuticals (>95% purity)], Kineret (20 mg/kg, Biovitrum), or no treatment. The posology of rytvela was based on reported efficacy (Quiniou et al., 2008 (link)) and further supported in subsequent studies (Nadeau-Vallee et al., 2015 (link); Beaudry-Richard et al., 2018 (link); Geranurimi et al., 2019 (link)).

All experiments involved newborn Sprague–Dawley rats (Charles River, Calco, Italy) and were performed in accordance with current European rules concerning the care and use of animals (Council Directive 2010/63/EU of the European Parliament and the Council of 22 September 2010 on the protection of animal used for scientific purposes) and 3R's guidelines. The Ethical Committee of the University of Milan approved the use of animals for cell culture.