A D1 agonist in the MPOA facilitates copulation in male rats

Markowski, Vincent P.; Eaton, Robert C.; Lumley, Lucille A.; Moses, Jason; Hull, Elaine M.

doi:10.1016/0091-3057(94)90147-3

Cited by 73 publications

(39 citation statements)

References 18 publications

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“…In the medial preoptic area, use of selective receptor agonists has established that low levels of dopaminergic stimulation, via D1 receptor in particular, facilitates erections. 18,19 In the paraventricular nucleus, similar experiments have established that D2 rather than D1 receptors primarily facilitate erections. 17 The mechanism of erection following paraventricular D2 receptor stimulation apparently involves oxytocinergic neurotransmission.…”

Section: Dopaminementioning

confidence: 81%

Neurotransmitters: central and peripheral mechanisms

2000

Int J Impot Res

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Re¯exive erection initiated by recruitment of penile afferents, involves both autonomic and somatic efferents. The re¯ex is mediated at the spinal cord level, modulated by supraspinal in¯uences, and may use several transmitters. Dopamine, acetylcholine, nitric oxide, and peptides, such as oxytocin and ACTHaa-MSH, seem to have a facilitatory role, whereas serotonin may be either facilitatory or inhibitory, and enkephalins are inhibitory. Peripherally, the balance between contractant and relaxant factors controls the degree of contraction of the smooth muscle of the corpora cavernosa, and determines the functional state of the penis. Noradrenaline contracts both corpus cavernosum and penile vessels via stimulation of a 1 -adrenoceptors. The role of endothelins in the control of penile smooth muscle tone is presently unclear. Neurogenic nitric oxide (NO) is considered the most important factor for relaxation of penile vessels and corpus cavernosum. The role of other mediators, released from nerves or endothelium has not been de®nitely established.

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Section: Dopaminementioning

confidence: 81%

Neurotransmitters: central and peripheral mechanisms

2000

Int J Impot Res

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“…First findings in copulating rats showed that MPOA D 1 -and D 2 -like receptors have opposite roles in the control of ejaculation. The former facilitates erectile mechanisms and enhances the rate of copulation, whereas the latter facilitates ejaculation (Hull et al, 1989;Markowski et al, 1994). It was thus suggested that MPOA D 1 -and D 2 -like receptor influences are related to the level of dopamine stimulation, with an evolution from the copulatory phase (mediated by D 1 receptors) to the ejaculatory phase (mediated by D 2 -like receptors) as dopamine concentration increases in this area (Hull et al, 1992).…”

Section: B Spinal Cordmentioning

confidence: 99%

Pharmacology for the Treatment of Premature Ejaculation

Giuliano

Clément

2012

Pharmacol Rev

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“…Therefore, D 1 and D 2 receptors in the MPOA have different thresholds of activation and different effects on autonomic control of genital reflexes. Finally, microinjections of THP into the MPOA facilitated copulation [83], whereas a high dose of the D 2 agonist quinelorane (LY-163502) delayed the start and slowed the rate of copulation but also decreased the number of intromissions required to trigger an ejaculation [84] (i.e., favored ejaculation at the expense of erection and the early stages of copulation). Therefore, synergy between D 1 and D 2 receptors in the MPOA occurs, in that activation of D 2 receptors may be required to disinhibit erections, which are then activated by stimulation of D 1 receptors by low to moderate levels of DA.…”

Section: Microinjection Of Dopamine Agonistsmentioning

confidence: 99%