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Updated: Sep 30, 2026

Intracavernosal Pressure Recording to Evaluate Erectile Function in Rodents
Published on: June 6, 2018
The effects of 5HT(1) agonists on erection in rats in vivo and rabbit corpus cavernosum in vitro
1The Department of Obstetrics and Gynaecology, The National University of Singapore, Singapore.
Abstract:
We have examined the effects of the selective 5-HT(1a) and 5-HT(1b) agonists 8-hydroxy-2-(di-n-propylamino)tetralin (8-OHDPAT) and 7-trifluoromethyl-4-(4-methyl-1-piperazinyl)-pyrrolo[1,2-a]quinoxaline (CGS12066b), respectively on erection in rats in vivo and rabbit corpus cavernosum in vitro. Apomorphine (0.1 mg/kg) induced 3.1+/-0.4 erections in vehicle-pretreated animals. At the highest doses tested 8-OHDPAT (0.4-0.64 mg/kg) and CGS12066b (1.0-10.0 mg/kg) significantly reduced apomorphine erection to 0.9+/-0.3 erections and 0.5+/-0.2 erections respectively. The nonselective 5-HT agonist metachlorophenylpiperazine (m-CPP; 0.1 mg/kg) elicited characteristic increases in cavernous nerve activity (CNA) and intracavernous pressure responses (ICP) in anesthetized rats. 8-OHDPAT (0.64 mg/kg) and CGS12066b (1.0 mg/kg) failed to elicit CNA or ICP responses. CGS12066b reduced ICP responses resulting from the direct stimulation of the cavernous nerve whereas 8-OHDPAT did not. CGS12066b reduced the CNA and ICP responses to m-CPP administration whereas 8-OHDPAT potentiated m-CPP induced CNA and ICP responses. In isolated rabbit corpus cavernosum (CC) 8-OHDPAT and CGS12066b both failed to alter noradrenergic induced contraction and non-adrenergic non-cholinergic relaxation. Our results indicate that selective 5-HT(1a) and 5-HT(1b) agonists have different effects in different models of erection.
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