Table 1.
Modification of cold-induced changes in cutaneous blood flow and body temperature by 5-HT1A receptors
| A. Cage temperature gradually from 26 to 15°C, then 8-OH-DPAT | ||||||
| Cage temperature 26°C | After 20 min at cage temperature 15°C | 5 min after 8-OH-DPAT (0.01 mg kg−1) | 5 min after 8-OH-DPAT (0.1 mg kg−1) | |||
| Ear pinna flow signal (cm s−1) | 44 ± 6(7) | 6 ± 2(7)* | 10 ± 4(6)*† | 55 ± 8(7)‡§ | ||
| B. Rabbit transferred from 26°C cage to 10°C cage, then 8-OH-DPAT or vehicle | ||||||
| 26°C cage | 30 min after transfer to 10°C cage | 5 min after 8-OH-DPAT (0.1 mg kg−1) or vehicle | 30 min after 8-OH-DPAT (0.1 mg kg−1) or vehicle | |||
| 8-OH-DPAT | ||||||
| Ear pinna blood flow (cm s−1) | 56 ± 7(7) | 5 ± 1 (7)* | 55 ± 8 (7)†‡ | 5 ± 1 (6)* | ||
| Body temperature(°C) | 38.8 ± 0.3(7) | 9.2 ± 0.4(7)* | 39.2 ± 0.4(7) | 38.7 ± 0.4(7)*‡ | ||
| Vehicle | ||||||
| Ear pinna blood flow (cm s−1) | 47 ± 10(5) | 5 ± 2(5)* | 3 ± 1(5)*§ | 2 ± 1(5)* | ||
| Body temperature(°C) | 39.1 ± 0.2(6) | 39.4 ± 0.2(6)‡ | 39.2 ± 0.4(6)‡ | 39.2 ± 0.1(6)‡ | ||
| C. 8-OH-DPAT in 26°C cage, transfer to 10°C cage, second 8-OH-DPAT injection after 30 min | ||||||
| 26°C cage, before 8-OH-DPAT | 26°C cage 5 min after 8-OH- DPAT (0.1 mg kg−1) | 5-30 min after transfer to 10°C cage | 60 min after transfer to 10°C cage | |||
| Ear pinna flow signal (cm s−1) | 78 ± 7(7) | 52.0 ± 5(7)* | 35 ± 7(7)‡ | 2 ± 1(7)† | ||
| Body temperature (°C) | 37.9 ± 0.4(7) | 38.0 ± 0.4(7) | 37.6 ± 0.3(7)‡ | 37.0 ± 0.3(7)† | ||
| D. Transfer from 26°C cage to 10°C cage, then 8-OH-DPAT, then WAY-100635 | ||||||
| 26°C cage | 30 min after transfer to 10°C cage | 5 min after 8-OH-DPAT (0.1 mg kg−1) | 5 min after WAY-100635 (0.1 mg kg−1) | 30 min after WAY-100635 | 15 min after transfer back to 26°C cage | |
| Ear pinna flow signal (cm s−1) | 51 ± 8(6) | 3 ± 1(6)* | 51 ± 10(6)†‡ | 4 ± 1(6)* | 4 ± 1(6)*§ | 41 ± 8(6)‡ |
| Body temperature(°C) | 38.4 ± 0.4(5) | 38.4 ± 0.4(5)‡ | 38.3 ± 0.4(5)‡ | 38.2 ± 0.4(5)‡ | 38.7 ± 0.5(5)‡ | 39.5 ± 0.6(5)* |
| E. Transfer from the 26°C cage to the 10°C cage, then WAY-100635 and then 8-OH-DPAT | ||||||
| 26°C cage | 30 min after transfer to 10°C cage | 5 min after WAY-100635 (0.1 mg kg−1) | 5 min after 8-OTH-DPAT (0.1 mg kg−1) | 30 min after 8-OTH-DPAT (0.1 mg kg−1) | 26°C cage | |
| Ear pina flow signal (cm s−1) | 69 ± 8(6) | 5 ± 1(6)* | 5 ± 1(6)*† | 4 ± 1(6)*† | 5 ± 1(6)*† | 44 ± 11(6)§ |
| Body temperatur(°C) | 38.7 ± 0.4(6) | 39.1 ± 0.4(6)‡ | 39.3 ± 0.4(6)‡ | 39.3 ± 0.4(6)‡ | 39.5 ± 0.4(6)‡ | 39.5 ± 0.6(6)‡ |
| F. WAY-100635 given in 26°C cage, then rabbit transferreed to 10°C cage, then 8-OH-DPAT | ||||||
| 26°C cage before WAY-100635 | 26°C cage 5 min after WAY-100635 (0.1 mg kg−1) | 30 min after transfer to 10°C cage | 5 min after 8-OH-DPAT (0.1 mg kg−1) | 30 min after 8-OH-DPAT (0.1 mg kg−1) | 26°C cage | |
| Ear pinna flow signal (cm s−1) | 51 ± 5(5) | 45 ± 5(5)§ | 6 ± 1(5)* | 7 ± 1(5)*‡ | 6 ± 1(5)*‡† | 25 ± 5(5)*† |
| Body temperature(°C) | 39.1 ± 0.6(5) | 39.2 ± 0.5(5)§ | 39.3 ± 0.5(5)§ | 39.3 ± 0.5(5)§ | 39.4 ± 0.4(5)§ | 39.5 ± 0.6(5)§ |
Effect on ear pinna blood flow and body temperature (mean ± s.e.m.) of intravenous administration of 8-hydroxy-2-(di-n-propy1amino)tetralin (8-OH-DPAT) or WAY-100635, either in a 26°C cage with gradual reduction of cage temperature to 15°C (A) or with transfer of the rabbit from the 26°C cage to a second cage maintained at 10°C (B–F). The heading of each subsection describes the experimental condition for that subsection. Explanation of symbols: A, *significantly different from 26°C control value, P < 0.01; †not significantly different from 20 min post transfer value, P > 0.05; ‡significantly different from 20 min post transfer value, P < 0.01; and §not significantly different from 26°C control value, P > 0.05. B, *significantly different from 26°C control value, P < 0.01; †significantly different from 30 min post transfer value, P < 0.01; ‡not significantly different from 26°C control value, P > 0.05; and §not significantly different from 30 min post transfer value, P > 0.05. C, *significantly different from 26°C control value before 8-OH-DPAT, P < 0.05; †significantly different from 26°C control value after 8-OH-DPAT, P < 0.01; and ‡not significantly different from 26°C control value after 8-OH-DPAT, P > 0.05. D, *significantly different from 26°C control value, P < 0.01; †significantly different from 30 min post transfer value, P < 0.01; ‡not significantly different from 26°C control value, P > 0.05; and §not significantly different from value 5 min after WAY-100635, P > 0.05. E, *significantly different from 26°C control value, P < 0.01; †not significantly different from 30 min post transfer value, P > 0.05; and ‡not significantly different from 26°C control value, P > 0.05. F, *significantly different from 26°C control value after WAY-100635, P < 0.01; †significantly different from 30 min post transfer value, P > 0.01; ‡not significantly different from 30 min post transfer value, P > 0.05; and §not significantly different from 26°C control value after WAY-100635, P > 0.05.