Figure 6.

Acute effect of melatonin on the response of plasma endocrine, metabolic variables, and Reactive oxygen species (ROS) markers during an episode of acute hypoxia. Norepinephrine (NE, A), cortisol (B), glucose (C), triglyceride (D), 8-isoprostane (E), and FRAP (F) plasma concentrations. Control newborn lambs receiving vehicle (white circles) and newborn lambs receiving an i.v., bolus of melatonin (0.27 mg kg⁻¹, black circles) 30 min before the first sampling interval. Nx, normoxia; Nx₁, normoxia after bolus; Hx, hypoxia; R, recovery (room air). Values are means ± SEM. Significant differences, P < 0.05: a, melatonin group vs. control group in the same period; b, hypoxia vs. other time periods in the same group; c, hypoxia vs. Nx₁; d, recovery vs. Nx in the same group; e, recovery vs. other time periods in the same group.