Table 1.
Cardiovascular baselines prior to tyramine and, in parenthesis, the response to pre-treatment.
| Pre-treatment | WKY |
SHR |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| N | MBP (mm Hg) | HR (beats/min) | CO (ml/min) | TPR (mm Hg/ml/min) | N | MBP (mm Hg) | HR (beats/min) | CO (ml/min) | TPR (mm Hg/ml/min) | |
| PBS (control) | 17 | 77 ± 4 (3 ± 3) |
338 ± 8 (−4 ± 7) |
36 ± 2 (4 ± 1) |
2.2 ± 0.2 (−0.2 ± 0.1) |
15 | 91 ± 4* (−6 ± 8) |
368 ± 8* (−20 ± 7) |
17 ± 1* (1 ± 1) |
5.4 ± 0.3* (−0.6 ± 0.2) |
| PBS after desipramine | 6 | 50 ± 2 (−2 ± 3) |
310 ± 14 (−4 ± 13) |
28 ± 3 (0 ± 1) |
1.9 ± 0.2 (−0.1 ± 0.1) |
6 | 63 ± 7† (−8 ± 3) |
350 ± 29 (−8 ± 5) |
13 ± 2 (−1 ± 0) |
4.8 ± 0.3 (−0.2 ± 0.3) |
| Atropine sulfate | 6 | 63 ± 6 (−8 ± 9) |
324 ± 11 (−16 ± 13) |
34 ± 2 (4 ± 3) |
1.9 ± 0.2 (−0.5 ± 0.2) |
6 | 99 ± 7 (−11 ± 15) |
356 ± 5 (−24 ± 8) |
19 ± 1 (2 ± 2) |
5.1 ± 0.3 (−1.3 ± 0.5) |
| PBS + clonidine | 7 | 64 ± 2 (−4 ± 5) |
316 ± 7 (−35 ± 7)† |
41 ± 3 (12 ± 1)† |
1.6 ± 0.1† (−0.8 ± 0.1)† |
10 | 56 ± 4† (−42 ± 7)† |
318 ± 9† (−113 ± 13)† |
16 ± 1 (−1 ± 1) |
3.5 ± 0.2† (−2.2 ± 0.4)† |
| L-659,066 | 6 | 50 ± 3† (−16 ± 2)† |
322 ± 11 (−25 ± 6) |
32 ± 3 (1 ± 1) |
1.6 ± 0.1 (−0.6 ± 0.0)† |
7 | 76 ± 5 (−12 ± 3) |
400 ± 14 (−23 ± 10) |
19 ± 2 (1 ± 1) |
4.3 ± 0.4 (−0.8 ± 0.2) |
| L-659,066 + clonidine | 8 | 50 ± 2† (−24 ± 2)†§ |
319 ± 7 (−48 ± 8)† |
32 ± 2 (3 ± 1) |
1.6 ± 0.1† (−1.0 ± 0.1)†§ |
7 | 44 ± 2†‡§ (−53 ± 7)†§ |
334 ± 13§ (−92 ± 15)†§ |
16 ± 1 (−4 ± 1)§ |
2.8 ± 0.1†‡§ (−2.3 ± 0.4)†§ |
Since desipramine was administered before cardiovascular recording was started, its effects were measured by the differences in baselines compared to that in the corresponding PBS-control group. After one-way ANOVA revealed the presence of group differences within each strain (P ≤ 0.05), these were located as indicated after comparisons between PBS-control and experimental groups ( †), between groups given L-659,066 + clonidine and PBS + clonidine (‡), and between the L-659,066 + clonidine and L-659066-treated groups (§). Comparison between WKY and SHR was done for the baselines in the PBS + tyramine control groups only (*). Baselines in the PBS + PBS time-control group did not differ from that in the corresponding PBS + tyramine control group (data not shown). *P ≤ 0.05. †, ‡, § – P ≤ 0.0071.