Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “VAS DEFERENS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

The relative potency of enkephalins and beta-endorphin in guinea-pig ileum, mouse vas deferens and rat vas deferens after the administration of peptidase inhibitors.

Previous studies have shown that three distinct enzymes, amastatin-sensitive aminopeptidase, captopril-sensitive peptidyl dipeptidase A, and phosphoramidon-sensitive endopeptidase-24.11, played a critical role in the inactivation of enkephalins in isolated preparations. In the present study, therefore, the rank order of the potency of three endogenous opioid peptides, [Met5]-enkephalin, [Leu5]-enkephalin, and beta-endorphin, in three isolated preparations, guinea-pig ileum, mouse vas deferens, and rat vas deferens, was estimated in the presence of the mixture of three peptidase inhibitors, amastatin, captopril, and phosphoramidon. [Met5]-Enkephalin was approximately three-fold more potent than [Leu5]-enkephalin and four-fold more potent than beta-endorphin in guinea-pig ileum in which three opioid peptides were indicated to act on mu-receptors. Additionally, [Met5]-enkephalin was slightly but significantly more potent than [Leu5]-enkephalin and approximately twenty-fold more potent than beta-endorphin at delta-receptor sites in mouse vas deferens. Moreover, [Met5]-enkephalin was approximately three-fold more potent than [Leu5]-enkephalin, but sixty-fold less potent than beta-endorphin in rat vas deferens in which the opioid-receptor type interacting with enkephalins could not be determined. In conclusion, the well-known rank order of the potency of three endogenous opioid peptides was shown to be altered in both guinea-pig ileum and mouse vas deferens but not in rat vas deferens by the pretreatment of the preparations with the mixture of three peptidase inhibitors.

Animals↗

Some pharmacological properties of the circular smooth muscle layer of the rat vas deferens.

Vas deferens preparations were perfused in-vitro through the lumen and externally with a modified Tyrode solution alone or containing drugs. Contractions of the circular (internal) smooth muscle layer were recorded as changes in the pressure of internal perfusion. Contractions of the longitudinal (external) layer were simultaneously recorded through a tension transducer. When the organ was perfused through the lumen, the circular layer contracted after addition of methacholine (pD2 = 4.13), and noradrenaline (pD2 = 5.00), and relaxed after addition of isoprenaline (pD2 = 5.22). These effects were also observed when the drugs were perfused externally, although with lower values of pD2 for noradrenaline and methacholine. The circular fibres were less sensitive when compared with the longitudinal fibres perfused externally with the above agonists. Methacholine-induced contractions of the circular layer were competitively antagonized by atropine (pA2 = 8.53), indicating the presence of muscarinic receptors. The effects induced by noradrenaline and isoprenaline were antagonized by indoramin (pA2 = 7.78), and timolol (pA2 = 8.68), respectively, indicating the presence of alpha- and beta-adrenoceptors. The effect of noradrenaline was potentiated by cocaine and denervation, indicating the presence of neuronal uptake, and by corticosterone, indicating the presence of extraneuronal uptake in the circular layer.

Animals↗

(-)-2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin (N-0923), a selective D2 dopamine receptor agonist demonstrates the presence of D2 dopamine receptors in the mouse vas deferens but not in the rat vas deferens.

Experiments were carried out using the D2 dopamine receptor-selective agonist (-)-2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin (N-0923) in the rat and the mouse isolated vas deferens to determine whether these tissues contained inhibitory D2 receptors in addition to their inhibitory alpha-2 adrenoceptors. In the mouse vas deferens N-0923 and the alpha-2 adrenoceptor agonist clonidine inhibited the electrically evoked twitch responses. The actions of clonidine, but not of N-0923, were antagonized by the alpha-2 antagonist idazoxan (pKb = 7.9), and responses to N-0923 were antagonized by the D2 antagonist sulpiride (pKb = 8.1). In the rat vas deferens, clonidine, but not N-0923, inhibited the twitch responses and these inhibitions were antagonized by idazoxan (pKb = 7.9) but not by sulpiride. Other D2 receptor agonists were tested in the mouse and in the rat vas deferens for their ability to activate D2 and alpha-2 receptors, respectively. At the D2 receptors in the mouse vas deferens (alpha-2 blocked) the potency order was (+)-propyl-9-hydroxy-naphtoxazine > pergolide > N-0923 = apomorphine > bromocriptine > quinpirole > dopamine. At the alpha-2 receptors in the rat vas deferens the potency order was pergolide > bromocriptine > (+)-propyl-9-hydroxynapthoxazine > apomorphine > quinpirole > or = dopamine. N-0923 was inactive but antagonized the responses to clonidine. N-0923 was therefore the most D2 receptor selective agonist tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-2 Receptor Antagonists↗

Formation of dopamine and noradrenaline in rat vas deferens: comparison with guinea-pig vas deferens.

1 The formation of [14C]-3,4-dihydroxyphenylalanine (DOPA) from [14C]-tyrosine, in the presence of the amino acid decarboxylase inhibitor, brocresine (3-hydroxy-4-bromobenzyloxyamine dihydrogen phosphate), was greatly enhanced in rat vasa deferentia depolarized by a KCl-enriched Krebs-Henseleit solution (52 mM KCl) compared with tissues maintained in unmodified Krebs-Henseleit solution. 2 When the conversion of tyrosine was allowed to proceed as far as catecholamine (brocresine absent) no significant difference was observed between the accumulation of [14C]-catecholamines (CA) in depolarized rat vasa deferentia and the accumulation in control (non-depolarized) tissues. 3 Endogenous CA levels in the depolarized rat vasa deferentia fell to 67% of the controls after a 1 h incubation period and to 53% at the end of 2 hours. 4 Chromatographic separation on Amberlite CG-120 columns of the newly synthesized CA and catechol metabolites from the rat vas deferens revealed that a very high proportion was present as dopamine. The percentage distribution after 1 h incubation in control Krebs-Henseleit was: noradrenaline (NA): 30.6 +/- 5.2; dopamine 56.9 +/- 5.9; acid metabolites: 12.8 +/- 1.1; and in KCl-rich Krebs-Henseleit, NA: 32; dopamine: 44.7 and acid metabolites 23.3. In contrast to the newly synthesized (14C-labelled) CA, endogenous dopamine comprises only 10% of the endogenous CA stores in rat vas deferens. 5 The distribution of newly synthesized NA and dopamine in rat vas deferens is strikingly different from that of guinea-pig vas deferens where more than 80% of newly formed amine is present as NA. In the latter tissue depolarization with K+ causes a striking increase in CA biosynthesis.

Animals↗

Spinal cord segments controlling the canine vas deferens and differentiation of the primate sympathetic pathways to the vas deferens.

This study was undertaken to explore the spinal cord segments controlling the canine and human vas deferens and differentiation of the mammalian sympathetic pathways to the vas deferens. Thoracolumbar white communicating rami (WCR) were electrically stimulated in the dogs. Stimulation of the 1st, 2nd, 3rd, and 4th lumbar WCR elicited an elevation of intraluminal pressure of the vas deferens in 2, 10, 16, and 14 of 20 dogs examined, respectively, whereas stimulation of sympathetic chain (between the 13th thoracic and 1st lumbar ganglia), 13th thoracic WCR, intermesenteric plexus, and 5th lumbar WCR showed no response in any of the 10, 2, 12, and 5 dogs examined, respectively. Anatomical study of the 118 human lumbar splanchnic nerves of 55 cadavers showed that almost all lumbar splanchnic nerves (96%) originated from L2 and/or L3 sympathetic chain ganglia (L1-2 spinal cord levels). Comparative anatomical study of the mammalian sympathetic pathways to the vas deferens showed that the caudal mesenteric plexus is not divided in rats, rabbits, cats, and dogs and is partially divided into two plexuses in monkeys and completely in humans and that separation of the sympathetic component in the pelvic nerve (isolation of the sacral splanchnic nerve) is in progress in the primate. These results indicate that spinal cord segments controlling the vas deferens are L1-4 in the dog and probably L1-2 in humans and that differentiation of the sympathetic nerve pathways is proceeding at both main and compensatory pathways to the vas deferens in the primate.

Animals↗

Acquisition of androgen-mediated expression of mouse vas deferens protein (MVDP) gene in cultured epithelial cells and in vas deferens during postnatal development.

We used cultured vas deferens epithelial cells (VDECs) as a model system to determine the conditions that allow mouse vas deferens protein (MVDP) gene expression and acquisition of androgen responsiveness. On the basis of Northern blot analysis, the mvdp gene is constitutively expressed at very low levels in prepubertal VDECs grown on collagen-coated plastic or on microporous membrane inserts. In the presence of dihydrotestosterone (DHT), mvdp messenger RNA levels dramatically increased in cells cultured on microporous membrane inserts and stayed unchanged in cells grown on matrix-coated plastic. Epithelial cells derived from fetal vas deferens were able to synthesize MVDP in response to DHT, and the presence of fetal mesenchymal cells did not influence MVDP production. Providing the cells with a culture procedure that permits access to the basolateral membranes and caters to the polarity requirements of the cell is a prerequisite for androgen induction of MVDP gene expression. The results also point to a role for epidermal growth factor, insulin, and tyrosine kinase activity in mediating the action of androgen on mvdp gene expression. In vivo studies show that the first expression of the mvdp gene between 5 and 7 days postpartum is not associated with major structural changes in the epithelium. The acquisition of a mature phenotype by epithelial and peritubular contractile cells, between 10 and 20 days, correlates with androgen dependency of the mvdp gene. We propose that cell differentiation and polarization on a matrix-coated microporous membrane reproduces some of the events that are necessary for acquisition of androgenic responsiveness of the mvdp gene during postnatal development.

3T3 Cells↗

Exportation of mouse vas deferens protein, a protein without a signal peptide, from mouse vas deferens epithelium: a model of apocrine secretion.

Mouse vas deferens protein (MVDP) is a major androgen-dependent protein of deferential fluid. It is specifically expressed in the epithelium of the mouse vas deferens. Its amino acid sequence as deduced from the nucleotidic sequence of its cDNA does not possess a signal sequence characteristic of secretory proteins. In vitro, transcription of MVDP cDNA followed by translation of mRNA in the rabbit reticulocyte system, in the absence or the presence of microsomes, demonstrated that there was no internalization of MVDP into microsomes that could protect it from degradation by proteinase K; this confirmed the absence of signal sequence. Moreover, MVDP has its NH2-terminus blocked. To understand how MVDP can be exported, its ultrastructural distribution and secretion process were analyzed by means of electron microscopy. Immunolocalization of MVDP revealed that it was distributed in the whole cytoplasm; it was never detected in the lumen of endoplasmic reticulum, Golgi apparatus, or vesicles but was abundant in apical protrusions and in the fluid, where it was associated with cellular material undergoing degradation. These data clearly demonstrated that exportation of MVDP into the luminal fluid does not occur in the classical manner for secretory proteins but rather involves an apocrine secretion process.

Aldehyde Reductase↗

Adrenergic contribution to the motor transmission in the dog vas deferens.

Isolated vas deferens preparations from 9 dogs were subjected to electrical stimulation and chemical excitation under physiological conditions. The experimental smooth muscle cylinders were confined to the terminal 3 cm portions of either the distal 'urethral' segment or the proximal 'epididymal' segment. Intermittent field stimulation, at 60 sec intervals, was provided by a stimulator of low output impedance under constant parameters of frequency and voltage and an occasionally varied pulse width. Results from this examination completely confirmed the following: (i) a high degree of contractile sensitivity to minute doses of noradrenaline (0.03--0.03 micron; 10(-8)-10(-7) g/ml) and tyramine 0.58 micron (10(-7) g/ml; (ii) an apparent ease and rapidity of extinguishing the electrically-induced twitches by either small doses of phentolamine 0.25 micron (10(-7) g/ml) or phenoxybenzamine 5.8 micron (2 x 10(-6) g/ml); (iii) a complete absence of any inhibitory action by tyramine or noradrenaline on the electrically-induced twitches. The behavior of this motor transmission of the longitudinal muscle of the vas deferens to classical alpha-adrenoceptor blocking agents and the intense susceptibility to the motor actions of the putative neurotransmitter clearly fit in with a picture of an adrenergic implication in this mode of transmission.

Adrenergic alpha-Antagonists↗

A T3 allele in the CFTR gene exacerbates exon 9 skipping in vas deferens and epididymal cell lines and is associated with Congenital Bilateral Absence of Vas Deferens (CBAVD).

The different alleles at the (TG)m(T)n polymorphic loci at the 3' end of the human CFTR intron 8 determine the efficiency by which exon 9 is spliced. We identified a novel TG12T3 allele in a congenital bilateral absence of vas deferens (CBAVD) patient who carries a [TG11T7; p.Phe508Cys; p.Met470Val] haplotype on the other chromosome. To better understand the complex regulation of exon 9 splicing, we analyzed the levels of correctly spliced CFTR transcripts in six CFTR-expressing epithelial cell lines derived from lung, colon, testis, vas deferens, and epididymis transiently transfected with four CFTR minigenes (pTG11T7, pTG12T7, pTG12T5, and pTG12T3). In this work, we show that a decrease in the Ts at the polymorphic locus in a TG12 background determines a cell-type dependent reduction in exon 9+ transcripts that is not related to the basal splicing efficiency in the cell line. These data emphasize the role of the T5 allele in CBAVD and identify the T3 allele as a severe cystic fibrosis (CF) disease-causing mutation. Finally, UV cross-linking experiments demonstrated that tissue-specific trans-acting splicing factors do not contribute to the different patterns of exon 9 splicing found between the cell lines. However, we observed that lower numbers of Ts can alter the binding of TDP-43 (TDP43 or TARDBP) to its specific target ug12 in a tissue-specific manner. Our results support the idea that the ratio of general splicing factors plays a role in the tissue variability of exon 9 alternative splicing.

Adult↗

Post-natal change in the effect of denervation on the rat vas deferens.

The vas deferens of 14-54 d old rats was denervated, isolated after 7 d, divided into prostatic and epididymal halves, and denervation supersensitivity to noradrenaline, acetylcholine, methacholine and tetramethylammonium (TMA) was examined. The supersensitivity to any of these agonists did not appear in rats younger than 21 d of age. Thereafter a leftward shift of the dose-response curve and an increase in the maximum contraction to noradrenaline were observed. The maximum contraction became progressively greater with development in the prostatic half but was approximately constant in the epididymal half. Supersensitivity to methacholine distinctly developed with age in the epididymal half. Only a subsensitivity to TMA was observed, suggesting that TMA acts on the nerve. The effect of denervation on the response to acetylcholine in the epididymal half resembled that to methacholine, and in the prostatic half resembled that to TMA. The developmental change in the effect of denervation on noradrenaline was discussed in relation to the full contractile ability of the vas halves, and that to cholinergic drugs was discussed in relation to nicotinic and muscarinic receptor population.

Acetylcholine↗

Identification of a functional androgen response element in the promoter of the gene for the androgen-regulated aldose reductase-like protein specific to the mouse vas deferens.

Mouse vas deferens protein (MVDP), a member of the aldo-keto reductase superfamily, is exclusively produced in the epithelial cells of the deferent duct under androgenic regulation. To better understand androgenregulated MVDP gene expression, the location and sequences of androgen response elements (AREs) in the 5'-flanking DNA were determined. Sequence analysis revealed two putative AREs as follows: one between positions -1186 and -1171 (distal ARE) and the other between -111 and -97 (proximal ARE). To study hormonal regulation, fragments of the MVDP promoter region, extending from residue -1804 to +41, were linked to the chloramphenicol acetyltransferase (CAT) reporter gene and cotransfected with a human androgen receptor expression vector into T47D cells in a transient expression assay. A minimal region (-121 to +41) was identified as being sufficient for androgen-regulated gene expression. A mutation in proximal ARE almost completely abolished androgen induction of CAT. One copy of the sequence TGAAGT tcc TGTTCT, cloned in the opposite orientation in front of the thymidine kinase promoter, confers androgen responsiveness to the CAT reporter gene. Androgen transcriptional activity was not detected with the distal ARE. The data provide strong evidence that transcriptional regulation of the MVDP gene occurs via the sequence TGAAGT tcc TGTTCT.

Aldehyde Reductase↗

Evidence for a strong non-adrenergic component in the motor transmission to the rabbit vas deferens.

Isolated vas deferens preparations from 16 rabbits of the New Zealand white strain were subjected to electrical and chemical excitability under physiological conditions and under the influence of drugs. Such smooth muscle fibres were strictly confined to the terminal 3 cm. segments of the distal 'urethral' portions of the vasa deferentia. Intermittent field stimulation, at 60 second intervals, was provided by a stimulator of low output impedance under constant parameters of voltage, pulse width and frequency. Results from this investigation revealed the undermentioned anomalous but distinct findings viz: (a) the presence of a minor adrenergic component which disappeared in phentolamine but remained unaffected by prolonged exposures to phenoxybenzamine; (b) the presence of a predominantly non-adrenergic component which was totally refractory to phenoxybenzamine but suffered a weak diminution in phentolamine; and (c) the picture of a phentolamine-insensitive but twitch-inhibiting effect shared by both tyramine and noradrenaline. Rabbit vasa consistently displayed a remarkable insensitivity to the motor effects of submicromolar concentrations of the putative neurotransmitter substance i.e. noradrenaline. The indirect sympathomimetic agent, tyramine failed to elicit any contractions when employed in doses as massive as 290 micrometers. i.e. 5 x 10(-5) g/ml, except in 2 out of 14 trials when a weak phentolamine-susceptible bursts of single contractions were produced. Thus, the adrenoceptors involved in the mediation of the twitch-inhibiting effects, appear not to behave towards conventional adrenoceptor antagonists in the classified manner. It seems appropriate therefore to invoke an unknown neurotransmitter for the non-adrenergic component in this motor transmission.

Adrenergic alpha-Antagonists↗

A radiolabeled-ligand-binding technique for the characterization of opioid receptors in the intact mouse vas deferens.

The mouse vas deferens has served as a useful bioassay for examining the properties of opiate receptor subtypes. However, recent data indicate that the response of the vas deferens to opiates may be mediated by one or more of the several opiate receptors found in this preparation. Although a number of techniques can be utilized to assess the relative contribution of these receptors to the response of the mouse vas deferens to opiates (e.g., selective tolerance and naloxone antagonism studies), a radiolabeled-binding technique would provide an independent means of more completely characterizing the opiate receptor profiles in this preparation. Up to the present, however, there has been only limited success in developing a binding assay utilizing crude membrane fractions of the mouse vas deferens. To circumvent these problems, we have developed a binding technique utilizing the intact vas deferens. In contrast to results obtained with membrane fractions, we found highly specific (90-95%) and saturable binding of D-[2-3H]alanine, 5-D-leucine enkephalin, a ligand selective for delta opiate receptors, to the intact vas. Scatchard analyses indicated a single class of binding sites with an apparent Kd of 1.5 nM and a Bmax of approximately 12 pmol/2 vas. The selectivity of binding was also examined. Naltrexone was 40 times less potent than unlabeled 2-D-alanine, 5-D-leucine enkephalin in displacing binding, whereas morphine and ethylketocyclazocine were 300 and 500 times less effective, respectively. This technique, coupled with the mouse vas deferens bioassay, should provide a more complete characterization of opioid receptor populations than has heretofore been possible.

Animals↗

Replacement of K+ with Rb+ or Cs+, and its effects on the mechanical responses to norepinephrine and methacholine in the rat vas deferens.

The rat vas deferens was stored overnight in cold, K+-free Krebs solution to deplete intracellular K+ then incubated in K+-, Rb+-, or Cs+-containing Krebs solution at 37 degrees C to load these ions inside the cells. After 4 h, the contents of K+ or Rb+ reached the level of K+ in the fresh vas deferens; the content of Cs+ was less than half that of the fresh vas deferens. Dose-response curves to norepinephrine and methacholine were determined under these conditions, and the curves in Rb+ or Cs+ solution were compared with those in K+ solution. The cold storage per se had little effect on the dose-response curves in K+ solution except that it slightly decreased the maximal response to norepinephrine. The dose-response curves in Rb+ solution were to the left of those in K+ solution. The maximal response to methacholine was greatly increased. On the other hand, the dose-response curves in Cs+ solution were to the right of those in K+ solution. The maximal responses were greatly decreased with both drugs. The results suggest that Rb+ but not Cs+ can fully substitute for K+ in the rat vas deferens response to norepinephrine and methacholine.

Animals↗

Autoradiographic localization of tritium-labeled dihydrotestosterone in human vas deferens.

The human vas deferens was examined autoradiographically for the presence and distribution of androgen receptors. Samples of vas deferens from the region proximal to the testis and the region at the internal inguinal ring were incubated in vitro with tritium-labeled dihydrotestosterone ([3H]-DHT). Frozen sections of tissue were mounted on autoradiographic emulsion-coated slides and exposed for up to three weeks to demonstrate cells with nuclear accumulations of radioactive hormone. Quantitation of autoradiograms was performed with a Zeiss Videoplan morphometric analysis system. Cells in all five tissue layers of the vas deferens were able to bind androgen receptors in the nucleus, as evidenced by superimposition of silver grains over the nuclei of cells in external, middle, and internal smooth muscle layers, as well as in epithelial and subepithelial stromal cells.

Autoradiography↗