Figure 3.
Variation in internal diameter of cerebral arterioles at systemic arterial mean pressure steps between 20 and 130 mmHg, during hypotensive hemorrhage before EDTA in 12-month-old (n=9), 24-month-old (n=9), and 24-month-old melatonin-treated (0.39 mg kg−1 in drinking water, n=11) IcoWI rats (a) and in 13-month-old (n=8), 25-month-old (n=11), and 25-month-old melatonin-treated (0.44 mg kg−1 in drinking water, n=6) WAG/Rij rats (b). Values are means±s.e.m. *P≤0.05 vs baseline in the same group. †P≤0.05 vs 12–13-month-old control. ‡P≤0.05 vs 24–25-month-old control.