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Table 4 Comparison of drug affinities at [ 3 H]clozapine binding sites in rat brain and cloned serotonin receptors

From: Clozapine: Selective Labeling of Sites Resembling 5HT6 Serotonin Receptors May Reflect Psychoactive Profile

Ligand 5HT1aa,b (nM) 5HT1Bc,d,e (nM) 5HT1Cf (nM) 5HT1Eg,h (nM) 5HT1Fi (nM) 5HT2j (nM) 5HT5Ak (nM) 5HT5Bk (nM) 5HT7l,m,n (nM) [3H]Clozapine (nM)
8-OH DPAT 0.06 >10,000 >1,000 >1,000 >10,0 398 35–52 5,000
5HT 0.27–1.66 16–48 8.14 70–125 250 251 251 0.6–1.8 200,000
Spiperone 63–134 >10,000 957 9.9–20 0.5 9.9–20 24.6
Mesulergine 400 3.0 >1,000 >1,000 21.1 1,000
Methysergide 436–1,823 300 6.3–14 1.0–5.0 63 126 13.4 8.2
Ketanserin 2,100–23,000 >10,000 28.5 3,162 1.0–5.0 >10,000 1,584 265–37,500 81.9
Ritanserin 2.7 0.2 15 123
Methiothepin 13 6.7 >1,000 0.4 700 15.8 0.3–8.8 9.8
Ergotamine 600 50–55 3.9 3.2 9.1
Sumatriptan 465 2,300 67–79 3.9 3.2 1,000 >1,000
Clozapine 4.2 7.2 5.0 4.0 5.3
  1. All numbers represent Ki values from the literature as noted or [3H]clozapine binding to rat brain membranes. Drug affinities for [3H]clozapine binding sites are mean values of two to three determinations varying less than 20%.
  2. aFargin et al. (19)
  3. bAlbert et al. (20)
  4. cMaroteaux et al. (21)
  5. dAdham et al. (22)
  6. eVoigt et al. (23)
  7. fRoth et al. (24)
  8. gZgombick et al. (25)
  9. hMcAllister et al. (26)
  10. iAmlaiky et al. (27)
  11. jMeltzer et al. (28)
  12. kMatthes et al. (29)
  13. lRoth et al. (30)
  14. mRuat et al. (31)
  15. nShen et al. (32)