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. 2013 Jan;58(1-2):140–149. doi: 10.1016/j.vph.2012.10.007

Table 1.

Potency and maximum vasoconstrictor responses for tryptamine in the absence and presence of inhibitors in the rat isolated perfused mesenteric arterial beds.

Signalling pathway and inhibitor Potency
(ED50, nmol/100 μl)
Maximum effects
(Emax, mm Hg)
n
5-HT2A receptors
 Control 32.0 (22.4–45.6) 37.3 ± 3.3 9
 Ritanserin (100 pM) 103.9 (14.2–760) 2.0 ± 0.4$$ 3
Nitric oxide synthase
 Control 35.2 (25.9–47.8) 32 ± 3 7
 l-NAME (100 μM) 33.4 (17.4–64.2) 90.1 ± 10.3⁎⁎⁎ 7
 l-NAME + ritanserin 9.0 (1.3–61.0) 8.6 ± 1.2 3
Denudation
 + Endothelium 81.0 (63.3–103.5) 12.4 ± 1.5 4
 − Endothelium 96.8 (24.7–379.2) 20.0 ± 2.3 4
Monoamine transporter
 Control 46.9 (33.7–65.4) 27 ± 1 4
 Cocaine (10− 5 M) 46.4 (33.2–64. 7) 51 ± 3⁎⁎ 4
 Cocaine + l-NAME 22.1 (6.5–75.5)## 126.4 ± 6.9### 4
Phospholipase C
 Control 38.8 (24.1–62.5) 43 ± 6 4
 U73,122 (10− 5 M) ND 8.6 ± 1.7⁎⁎ 4
Phospholipase A2
 Control 29.6 (12.8–68.4) 18 ± 2 3
 PACOCF3 (10− 5 M) 92.1 (55.5–152.8) 18 ± 2 3
Rho-kinase
 Control 26.2 (12.5–54.7) 20 ± 4 3
 Y-27,632 (10− 5 M) 18.9 (5.9–61.0) 11 ± 3⁎⁎ 3
 Control 27.50 (13.24–57.1) 26 ± 3 3
 Fasudil (2 × 10− 5 M) 18.9 (4.3–82.6) 9 ± 1⁎⁎ 3
COX-1 and COX-2
 Control 29.2 (17.0–50.1) 25 ± 3 5
 Indomethacin (10− 5 M) ND 10.4 ± 1.7⁎⁎ 5
COX-2
 Control 28.9 (12.7–65.7) 45 ± 1 3
 Nimesulide (10− 5 M) 57.6 (52.7–63.0) 22 ± 2⁎⁎ 3
Prostanoid EP1 receptor
 Control 32.0 (21.1–48.7) 20 ± 3 4
 AH-6809 (10− 5 M) 49.0 (32.6–73.7)* 14 ± 3 4
Prostacyclin synthase/MAO
 Control 29.4 (21.2–40.8) 28 ± 7 5
 Tranylcypromine (10− 5 M) 20.1 (14.1–28.6) 27 ± 3 5
Thromboxane TP receptor
 Control 29.8 (20.5–43.4) 24 ± 5 4
 ICI 192605 (10− 6 M) 28.8 (15.6–53.5) 27 ± 5 4

Potency is represented as the geometric mean (with 95% confidence intervals) ED50 (nmole/100 μl) and the maximum response is displayed as arithmetic mean ± S.E.M maximum increase in perfusion pressure (mm Hg). n is the number of animals. * Represents significant differences from paired control values by Student's paired t-test, P < 0.05, ** P < 0.01 and *** P < 0.001. $$ Significant difference from unpaired controls by Student's unpaired t-test, P < 0.01. ## Significant differences between the l-NAME plus cocaine group and control or cocaine alone by one-way ANOVA with Tukey's multiple comparison test, P < 0.003, ###P < 0.0001. ND, not determined.