Characteristics of α-adrenoceptor antagonists-induced ejaculatory dysfunction on spontaneous seminal emission in rats.

Although α-adrenoceptor (α-AR) antagonists used to treat benign prostatic hyperplasia can cause ejaculation disorders, the aetiology of this adverse event is still controversial. Therefore, we investigated the effects of antagonists with different affinities for α-AR subtypes on ejaculatory function and their mechanisms of action in normal rats. In the spontaneous seminal emission (SSE) test, systemically administered prazosin, terazosin, tamsulosin and naftopidil decreased the weight of ejaculated seminal material in a dose-dependent manner; the potency order was as follows: tamsulosin > terazosin > prazosin > naftopidil.

Central Mechanisms of Apomorphine and m-Chlorophenylpiperazine on Synergistic Action for Ejaculation in Rats.

Background: We previously reported that the combination of the dopamine (DA) receptor agonist apomorphine and the 5-hydroxytryptamine (5-HT) receptor agonist m-chlorophenylpiperazine (m-CPP) in rats potently and selectively facilitates the ejaculatory response through activation of D-like and 5-HT receptors, respectively.

Aim: The aim of this study was to clarify the target level of the proejaculatory effects induced by combination of these agonists.

Methods: For in vivo behavioral studies, apomorphine and m-CPP were given intracerebroventricularly and intrathecally alone or in combination with either drug administered systemically.

[An Analysis of the Educational Effects of Studying Basic Life Support].

We set students' learning goal of basic life support (BLS) education at "being able to describe all the steps of BLS in an appropriate order", and objectively analyzed the appropriateness of the learning goal we set and educational effects of lecture contents. Before delivering a lecture, we provided students with an assignment which asked them to "Describe the steps of BLS in an appropriate order", and investigated students' levels of acquiring knowledge on BLS. As the results, the majority of students failed to perform this assignment.

Involvement of multiple µ-opioid receptor subtypes on the presynaptic or postsynaptic inhibition of spinal pain transmission.

The involvement of the μ-opioid receptor subtypes on the presynaptic or postsynaptic inhibition of spinal pain transmission was characterized in ddY mice using endomorphins. Intrathecal treatment with capsaicin, N-methyl-d-aspartate (NMDA) or substance P elicited characteristic nociceptive behaviors that consisted primarily of vigorous biting and/or licking with some scratching. Intrathecal co-administration of endogenous μ-opioid peptide endomorphin-1 or endomorphin-2 resulted in a potent antinociceptive effect against the nociceptive behaviors induced by capsaicin, NMDA or substance P, which was eliminated by i.

Involvement of spinal release of α-neo-endorphin on the antinociceptive effect of TAPA.

The antinociceptive effect of i.t.-administered Tyr-d-Arg-Phe-β-Ala (TAPA), an N-terminal tetrapeptide analog of dermorphin, was characterized in ddY mice.

Distinct physiological role of amidino-TAPA-sensitive and DAMGO-insensitive μ-opioid receptor splice variants in the mouse spinal cord.

The physiological role of the distinct splice variants for cloned mouse μ-opioid receptor (mMOR-1), mMOR-1J, mMOR-1K and mMOR-1L, which are sensitive to N(α)-amidino-Tyr-D-Arg-Phe-β-Ala (amidino-TAPA) and insensitive to [D-Ala(2),N-MePhe(4),Gly-ol(5)]enkephalin (DAMGO), was described in the mouse spinal cord. The antinociception induced by intrathecally (i.t.

Partial involvement of NMDA receptors and glial cells in the nociceptive behaviors induced by intrathecally administered histamine.

The involvement of spinal glial cells in the nociceptive behaviors induced by 800 pmol of histamine was determined in mice. Histamine at 800 pmol injected intrathecally (i.t.

Involvement of glial cells in the nociceptive behaviors induced by a high-dose of histamine administered intrathecally.

The involvement of spinal glial cells in the nociceptive behaviors induced by 1600 pmol of histamine was determined in mice. Histamine injected intrathecally (i.t.

Involvement of mouse μ-opioid receptor splice variants in the spinal antinociception induced by the dermorphin tetrapeptide analog amidino-TAPA.

The involvement of the mouse μ-opioid receptor (mMOR-1) splice variants in the antinociceptive effect of intrathecally (i.t.) administered N(α)-amidino-Tyr-D-Arg-Phe-β-Ala (amidino-TAPA) and [D-Ala(2),N-MePhe(4),Gly-ol(5)]enkephalin (DAMGO) was investigated in mice by monitoring the recovery from acute antinociceptive tolerance to amidino-TAPA and DAMGO.

Lack of a rewarding effect and a locomotor-enhancing effect of the selective μ-opioid receptor agonist amidino-TAPA.

Rationale And Objectives: Psychological dependence is one of the worst side effects of morphine. It limits the clinical availability of morphine and non-patient morphine users suffer from addiction. An analgesic, which is more potent than morphine but without the liability of psychological dependence, has long been sought in the clinic.

Role of supraspinal and spinal alpha1-adrenergic receptor subtypes in micturition reflex in conscious rats.

α(1)-Adrenergic receptor subtypes are widely distributed in the central nervous system and are involved in autonomic functions such as micturition. We investigated the presence and the role of supraspinal and/or spinal α(1)-adrenergic receptors in modulating the micturition reflex in conscious female Wistar rats. The expression of α(1)-adrenergic receptor subtypes in rat brain and lumbosacral spinal cord was studied using RT-PCR.

Characterization of intrathecally administered hemokinin-1-induced nociceptive behaviors in mice.

Hemokinin-1 is a novel mammalian tachykinin cloned from mouse bone marrow. At present, pharmacological profile and physiological role of hemokinin-1 are still unclear. In the present study, we found that intrathecal (i.

New therapy for neuropathic pain.

Neuropathic pain is one of the worst painful symptoms in clinic. It contains nerve-injured neuropathy, diabetic neuropathy, chronic inflammatory pain, cancer pain, and postherpes pain, and is characterized by a tactile allodynia and hyperalgesia. Neuropathic pain, especially the nerve-injured neuropathy, the diabetic neuropathy, and the cancer pain, is opioid resistant pain.

Synergistic actions of apomorphine and m-chlorophenylpiperazine on ejaculation, but not penile erection in rats.

It has been suggested that dopamine (DA) and serotonin (5-HT) and their receptors, particularly D(2)-like and 5-HT(2C) receptors, may play a significant role in the control of male sexual function. The purpose of this study was to investigate whether the combination of a dopamine receptor agonist apomorphine and a 5-HT(2) receptor agonist m-CPP would potentiate penile erection and ejaculation in male rats. Systemic administration of either apomorphine (0.

Effects of insulin replacement on ejaculatory dysfunction in streptozotocin-induced diabetic rats.

Objectives: To investigate the effects of insulin replacement on ejaculatory dysfunction in streptozotocin (STZ)-induced diabetic rats.

Methods: Rats were divided into three groups: (i) STZ-treated group; (ii) STZ-treated + insulin replacement (5 and 2 international units [IU]) group; and (iii) control group. The ejaculatory function in rats was evaluated using the spontaneous seminal emission (SSE) test.

Possible involvement of dynorphin A release via mu1-opioid receptor on supraspinal antinociception of endomorphin-2.

It has been demonstrated that the antinociception induced by i.t. or i.

Intrathecal high-dose histamine induces spinally-mediated nociceptive behavioral responses through a polyamine site of NMDA receptors.

Previous research has demonstrated that a high dose of histamine (1600 pmol) injected i.t. in mice can evoke nociceptive behaviors consisting of biting/licking along with occasional scratching.

Ejaculatory response induced by a 5-HT2 receptor agonist m-CPP in rats: differential roles of 5-HT2 receptor subtypes.

It has been reported that systemic administration of m-CPP (1-[3-chlorophenyl] piperazine hydrochloride), a 5-HT(2) receptor agonist, produces a 5-HT(2C) receptor-mediated penile erections and self-grooming in rats. In the present study, we examined the ability of m-CPP to induce ejaculation in rats and determined which 5-HT(2) receptor subtypes may be involved in the m-CPP-induced ejaculation. The ejaculatory response was assessed by weighing the seminal materials accumulated over 30 min.

Involvement of endogenous opioid peptides in the antinociception induced by the novel dermorphin tetrapeptide analog amidino-TAPA.

The antinociceptive effect of i.t. administered N(alpha)-amidino-Tyr-d-Arg-Phe-beta-Ala (amidino-TAPA), an N-terminal tetrapeptide analog of dermorphin, was characterized in ddY mice.

Possible involvement of endogenous nociceptin/orphanin FQ in the pain-related behavioral responses induced by its own metabolite, nociceptin/orphanin FQ(14-17).

Nociceptin/orphanin FQ(14-17) (N/OFQ(14-17)) is one of the major fragments that are released from N/OFQ, an endogenous ligand for the opioid receptor like-1 (ORL-1) receptor by endopeptidase 24.11. In the present study, we determined the pharmacological profiles of N/OFQ(14-17) on pain-related behavioral responses in the mouse.

Evidence for an involvement of peripheral serotonin in p-chloroamphetamine-induced ejaculation of rats.

The purpose of the present study was to determine the mechanism of the ejaculatory response induced by the 5-HT-releasing compound p-chloroamphetamine (PCA) in rats. The ejaculatory response was assessed by weighing the coagulated seminal materials accumulated over 1 h. Intraperitoneal injection of PCA (0.

Long-lasting effects of yohimbine on the ejaculatory function in male dogs.

Previous studies have demonstrated that systemic administration of a low dose of the alpha2-adrenoceptor antagonists stimulates the ejaculatory response of male dogs, when this function is analyzed using the amount of ejaculated semen in response to genital stimulation. The present study was designed to further examine the features of the stimulatory effects of the alpha2-adrenoceptor antagonists on ejaculation, especially the duration of action. Treatment with yohimbine (0.

Involvement of the histaminergic system in the nociceptin-induced pain-related behaviors in the mouse spinal cord.

Intrathecal (i.t.) injection of nociceptin elicited a behavioral response mainly consisting of biting and licking, which were eliminated by the i.

Differential involvement of mu 1-opioid receptors in dermorphin tetrapeptide analogues-induced antinociception.

The involvement of putative mu(1)-opioid receptors in the antinociception induced by the dermorphin tetrapeptide analogues Try-D-Arg-Phe-beta-Ala (TAPA) and Tyr-D-Arg-Phe-beta-Ala-NH(2) (TAPA-NH(2)) was determined in mice, using a tail-pressure test and a formalin test. TAPA and TAPA-NH(2) injected i.c.