title: Inhibitory effect of 5-hydroxytryptamine on penile erectile function in the rat.
abstract: 1. An increase in corporal pressure was elicited in pithed rats by stimulation of the sacral part of the spinal cord. This response was inhibited by intravenous injection of 5-hydroxytryptamine (5-HT) (ED50 = 28.5 +/- 2.2 micrograms kg-1). 2. The inhibitory effect of 5-HT was blocked by methysergide and methiothepin (each 1 mg kg-1), but not by ketanserin (0.02 mg kg-1), MDL 72222 (1 mg kg-1) or prazosin (0.1 mg kg-1). 3. An inhibitory effect on the corporal pressure response to spinal stimulation was also produced by 5-carboxyamidotryptamine (ED50 = 5.6 +/- 2.8 micrograms kg-1), but not by m-chlorophenylpiperazine (mCPP), RU 24969, 8-hydroxy-2-[di-n-propyl-amino]-tetralin (8-OH-DPAT) or fenfluramine (doses up to 1-2 mg kg-1). 4. Neither methiothepin (1 mg kg-1) nor clomipramine (1 mg kg-1) had any effect on the frequency-response curve for increase in corporal pressure by spinal stimulation. 5. The results indicate that 5-HT exerts an inhibitory action on penile erection by a peripheral mechanism. This effect may be mediated by vasoconstriction in cavernosal vessels, or inhibition of release of a vasodilator neurotransmitter. From the spectrum of agonist and antagonist responses, the receptor involved may be of the 5-HT1D subtype.
authors.affiliation: Rappaport Family Institute for Research in the Medical Sciences, Technion, Haifa, Israel.
authors.forename: J P
authors.initials: JP
authors.lastname: Finberg
authors.forename: Y
authors.initials: Y
authors.lastname: Vardi
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003655:Decerebrate State; D004558:Electric Stimulation; D008297:Male; D010410:Penile Erection / Q000187:drug effects* / Q000502:physiology; D010413:Penis / Q000098:blood supply; D051381:Rats; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology* / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects
chemical_list: D011985:Receptors, Serotonin; D012701:Serotonin