Intraluminal pressures in the seminiferous tubules and in different regions of the epididymis in the rat

Pholpramool, Chumpol; Triphrom, N.; Dinudom, Anuwat

doi:10.1530/jrf.0.0710173

Cited by 24 publications

(14 citation statements)

References 15 publications

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“…The testis and the epididymis were prepared for micropuncture and intraluminal pressure measurements as previously described (Pholpramool et al, 1984). The sites of pressure measure¬ ments in the epididymis were the mid-caput (site 2), the mid-corpus (site 4) and the proximal cauda (site 6).…”

Section: Micropuncture and Measurements Of Intraluminal Pressurementioning

confidence: 99%

“…The contractility of different regions of the epididymis can be studied by micropuncture using a servo-nulling transducer system (Pholpramool, Triphrom & Din-Udom, 1984). In the present investigation, we employed the same method to study the effects of autonomie drugs on intra¬ luminal pressures and contractility of the seminiferous tubules and different regions in the epididymis of rats in vivo.…”

Section: Introductionmentioning

confidence: 99%

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Effects of cholinergic and adrenergic drugs on intraluminal pressures and contractility of the rat testis and epididymis in vivo

Pholpramool¹,

Triphrom²

1984

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Intravenous administration of methacholine (200 micrograms/kg) caused no changes in the seminiferous tubules of rats, but significantly increased intraluminal pressures and contractility of the caput, the corpus and the cauda epididymidis. The effect of methacholine was abolished by pretreatment with atropine (500 micrograms/kg), but not by phentolamine (400 micrograms/kg) or propranolol (400 micrograms/kg). Adrenaline (5-40 micrograms/kg), noradrenaline (5-40 micrograms/kg) and phenylephrine (100-400 micrograms/kg) had no effect on the seminiferous tubules, but dose-dependently elevated intraluminal pressures and enhanced the contractility of all regions of the epididymis. Isoproterenol (100-800 micrograms/kg) did not affect intraluminal pressures of the seminiferous tubules and the epididymal duct. The stimulatory effect of adrenergic agonists was specifically blocked by phentolamine, but not by propranolol or atropine. Cholinergic and adrenergic antagonists did not alter spontaneous contraction of the epididymis. The results suggest that the contractility of all segments of the rat epididymis, but not the seminiferous tubules, can be increased by autonomic drugs. The enhancing effect of adrenergic drugs is probably the result of activation through alpha-adrenergic receptors.

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Section: Micropuncture and Measurements Of Intraluminal Pressurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of cholinergic and adrenergic drugs on intraluminal pressures and contractility of the rat testis and epididymis in vivo

Pholpramool¹,

Triphrom²

1984

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“…Predominantly, noradrenergic output stimulates epididymal muscle activity and emission of sperm during ejaculation (Pholpramool et al 1984, Billups et al 1990, Kempinas et al 1998. The effects of noradrenaline (NA) seem to be primarily mediated not only by postjunctional a 1 -adrenoceptors (ADRA; Pholpramool et al 1984, Ventura & Pennefather 1991, Chaturapanich et al 2002, but also by a 2 -ADRA (Haynes & Hill 1996, Chaturapanich et al 2002.…”

Section: Introductionmentioning

confidence: 99%

Differential modulation of bovine epididymal activity by oxytocin and noradrenaline

Mewe¹,

Wulfsen²,

Middendorff³

et al. 2007

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Passage of spermatozoa through the epididymis and emission of sperm during ejaculation are based on spontaneous and induced contractions of epididymal peritubular muscle layers. This study deals with the ejaculation-relevant factors noradrenaline (NA) and oxytocin (OT) and their contractile effects in the course of the bovine epididymal duct. Muscle tension recording revealed excitatory effects of NA in all duct regions. A peculiarity was found in a duct section between the mid-cauda and ductus deferens, where the responsiveness to NA was particularly faint in comparison with the adjacent regions. NA-induced contraction was primarily mediated by postjunctional a 2 -adrenoceptors (ADRA) in the caput and corpus regions, and by a 1 -ADRA in the cauda region. Contrary to NA, OT exerted regionally varying effects. The peptide induced contraction in intact and epithelium-denuded caput as well as in epithelium-denuded corpus segments but had a relaxant net effect in intact corpus and proximal cauda segments. Within the mid-cauda, OT evoked strong contraction, which progressively decreased distally. Receptor specificity of the epididymal OT effects was verified using the selective OT receptor (

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“…The transport of spermatozoa through the epididymis is mainly the result of spontaneous contractions of the smooth muscle surrounding the epididymal duct, and can be modified (accelerated) by cholinergic or adrenergic drugs in all regions of epididymis (Pholpramool & Triphrom, 1984;Chaturapanich et al, 1999). Although the distal cauda of epididymis presents an abundant sympathetic innervation comparing with other regions of this organ (Ricker, 1998), the presence of adrenoceptors are also suggested in caput and corpus (Pholpramool & Triphrom, 1984;Pholpramool et al, 1984;Queiroz et al, 2008), indicating a major functional role in the epididymis.…”

Section: (A) (B) (C)mentioning

confidence: 99%

Epididymal contraction and sperm parameters are affected by clonidine

et al. 2014

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SUMMARYThe use of clonidine, a selective agonist of a 2 -adrenoceptors, is related to the fertility impairment. Thus, it has been described that changes in the epididymal function are related to the loss of fertility. Therefore, this study was sought to further evaluate the effects of clonidine in the rat distal cauda epididymis contractions and its consequence in the sperm parameters. The in vitro effects of clonidine in the isolated distal cauda epididymis were evaluated by pharmacological experiments. The consecutive contractile responses for clonidine in distal cauda epididymis showed desensitization. The noradrenaline-induced contractions were desensitized after in vitro clonidine pre-treatment (10 À5 M for 10 min). Clonidine was unable to alter the noradrenaline contractions if the in vitro pre-treatment was made in the presence of idazoxan (a 2 -adrenoceptor antagonist), whereas prazosin (a 1 -adrenoceptor antagonist) was ineffective. Moreover, the in vitro clonidine pre-treatment increased frequency and amplitude of spontaneous contraction of distal cauda epididymis. In addition, to induce in vivo desensitization of a 2 -adrenoceptors, male Wistar rats were treated with crescent doses of clonidine and distal cauda of epididymis contraction and sperm parameters were analyzed. The in vivo treatment with clonidine diminished the potency of the contractions induced by adrenergic agonists and augmented the frequency and amplitude of spontaneous contraction of distal cauda epididymis. This treatment also altered the sperm transit time in epididymis, epididymal sperm reserves, sperm lipid peroxidation, and antioxidant enzymes activity. The results suggest that clonidine was able to affect the sperm quantity and quality by decreasing the transit time related to the increase in the frequency and amplitude of spontaneous contractions in epididymis, although the contractions induced by adrenergic agonists were desensitized.

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Intraluminal pressures in the seminiferous tubules and in different regions of the epididymis in the rat

Cited by 24 publications

References 15 publications

Effects of cholinergic and adrenergic drugs on intraluminal pressures and contractility of the rat testis and epididymis in vivo

Effects of cholinergic and adrenergic drugs on intraluminal pressures and contractility of the rat testis and epididymis in vivo

Differential modulation of bovine epididymal activity by oxytocin and noradrenaline

Epididymal contraction and sperm parameters are affected by clonidine

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