Table 2.

Effects of isorhynchophylline (IRN), at the concentration range of 0.01-100 nM, on mean EC₅₀ and E_max values of 8-OH-DPAT for its stimulation of [³⁵S] GTPγS binding to 5-HT_1A expressing CHO cell membranes.

Pretreatment	Mean EC50 (nM)	95% confidence limits (nM)	Mean Emax (%)	95% confidence limits (nM)	n
vehicle	15.4	9.7–24.6	98.7	92.4–105.2	10
0.01 nM IRN	18.2	10.5–31.5	101.6	95.3–107.7	10
vehicle	14.3	9.2–22.1	97.8	92.5–103.3	9
0.1 nM IRN	28.7	15.5–53.2	120.3**	113.0–127.9	9
vehicle	13.9	7.8–24.8	98.3	90.5–106.4	10
1 nM IRN	26.3	14.5–47.9	132.9**	123.4–142.8	10
vehicle	15.8	8.9–27.8	99.7	93.2–106.4	10
10 nM IRN	32.4	17.9–58.8	124.8**	117.3–132.2	10
vehicle	15.6	9.6–25.3	101.7	94.5–109.1	9
100 nM IRN	16.3	9.4–28.3	104.8	98.0–110.9	9

**p < 0.01, compared with respective vehicle group (values in the previous row). See also Figure 8.