Table 2.
Baseline values in 13-month-old control (n=8), 25-month-old control (n=11) and 25-month-old melatonin-treated WAG/Rij rats (0.44 mg kg−1 in drinking water, n=7)
| Parameters | 13-month-old control | 25-month-old control | 25-month-old+melatonin |
|---|---|---|---|
| Body weight | 380±8 | 372±11 | 358±9 |
| Systemic arterial pressure (mmHg) | |||
| Systolic | 126±2 | 127±4 | 120±6 |
| Diastolic | 90±2 | 91±3 | 85±5 |
| Mean | 103±2 | 105±4 | 99±5 |
| Pulse | 36±1 | 36±1 | 35±2 |
| Heart rate (beats min−1) | 347±11 | 327±11 | 322±10 |
| Arterial blood gases | |||
| pCO2 (mmHg) | 30±1 | 31±1 | 31±1 |
| pO2 (mmHg) | 74±2 | 81±3 | 75±4 |
| pH | 7.52±0.01 | 7.50±0.02 | 7.51±0.01 |
| Cerebral arteriolar pressure (mmHg) | |||
| Systolic | 44±2 | 49±4 | 49±4 |
| Diastolic | 39±2 | 42±4 | 42±4 |
| Mean | 41±2 | 46±4 | 46±4 |
| Pulse | 6±1 | 7±1 | 7±1 |
| CBF (arbitrary units) | 13.7±0.9 | 12.4±0.9 | 10.9±0.3 |
| Lower limit of CBF autoregulation (mmHg) | 53±2 | 67±6 | 45±4‡ |
| Security margin (%) | 48±2 | 36±6 | 54±4 |
| Cerebral arterioles before deactivation | |||
| Internal diameter (μm) | 41.6±3.2 | 45.0±2.4 | 45.9±2.9 |
| Cerebral arterioles after deactivation | |||
| CSA of wall (μm2) | 328±25 | 341±20 | 435±25†‡ |
Values are means±s.e.m. CBF, cerebral blood flow; CSA, cross-sectional area.
†
P≤0.05 vs 13-month-old control.
‡
P≤0.05 vs 25-month-old control.