Sympathetic efferent pathways projecting bilaterally to the vas deferens in the rat

ABSTRACT Background: The laterality of the signals passing through the splanchnic nerves to the vas deferens has not been well studied. Methods: The present study was designed to determine the bilateral distribution of sympathetic nerves to the rat vasa deferentia by measuring intravasal pressure (VP) responses to electrical stimulation of left lumbar splanchnic nerves (LSN) following consecutive transections of more distal nerves. Results: L₂-L₆ LSN stimulation increased VP bilaterally. Left VP responses decreased slightly (<20%) after section of the right hypogastric nerve (HGN) and then were abolished by subsequent section of branches (B-M-APG) between the left major pelvic (MPG) and accessory pelvic ganglia (APG). Left VP responses were decreased by >80% after section of left HGN, not changed further by subsequent section of commissural branches (CB-MPG) between the MPG, and completely eliminated by section of commissural branches between the APG (CB-APG). Right VP responses were decreased slightly (<20%) by section of the left HGN and then abolished by section of the right B-M-APG. These responses were also decreased by >70% by section of right HGN, not changed by section of CB-MPG, but then completely eliminated by section of CB-APG. Conclusions: These results indicate that the left lumbar sympathetic pathway to the vas deferens is distributed bilaterally and exhibits two crossing points at the level of the inferior mesenteric ganglion and APG. Anat. Rec. 248:291-299, 1997. © 1997 Wiley-Liss, Inc.     

Release of 3H-noradrenaline from the rat vas deferens under various in vitro conditions

The release of ³H-(-)-noradrenaline (NA) from rat vas deferens in vitro was examined under various experimental conditions. It was found that in normal and reserpinized vas deferens the release of NA evoked by (+)-amphetamine (5 times 10^?6 M) or low external Na⁺ (26 mM) was antagonized by imipramine methiodide and desipramine, inhibitors of the NA uptake, but was not dependent on the presence of Ca²⁺ in the medium and was not antagonized by the potent local anaesthetic agent bethoxycaine. The release evoked by veratridine in reserpinized tissue was antagonized by the uptake inhibitors but was in normal tissue only partially inhibited in presence of Ca²⁺ but almost completely in absence of Ca²⁺. The release by high K⁺ (117 mM) + low Na⁺ (26 mM) in normal tissue was dependent on the presence of Ca²⁺ and was antagonized by the muscarinic agonists carbacholine and metacholine and by high concentrations of desipramine. In the reserpinized vasa the corresponding release was not dependent on Ca²⁺ and was not antagonized by the muscarinic agents but was inhibited by high concentrations of desipramine.     

Inhibitory effect of adenosine on electrically evoked contractions in the rat vas deferens: pharmacological characterization

The inhibitory effects of adenosine as well as its related analogues on the contractile response of the rat vas deferens to field stimulation were compared in the absence and in the presence of nitrobenzylthioguanosine (NBTGR), a potent adenosine uptake inhibitor. In the presence of NBTGR, the order of potency was N6-cyclohexyladenosine (CHA) greater than or equal to L-N6-phenylisopropyladenosine (L-PIA) greater than 2-chloroadenosine greater than D-N6-phenylisopropyladenosine (D-PIA) greater than or equal to adenosine greater than 2'-deoxyadenosine. The inhibitory effect of adenosine but not that of clonidine, beta-endorphin and somatostatin was blocked by 1,3-diethyl-8-phenylxanthine (DPX, pA2 = 7.2), a potent P1-purinergic antagonist. The results suggest that adenosine inhibited the electrically evoked contractions of the rat vas deferens via the activation of the A1 subtype of P1-purinergic receptors.     

Reserpine-induced potentiation of the inhibitory action of neuropeptide Y on the rat vas deferens neurotransmission

The inhibitory action of neuropeptide Y (NPY) on the muscular activity of the prostatic end of the rat vas deferens elicited by transmural electrical stimulation was examined in control and in reserpinized rats. Pretreatment with 1 mg/kg reserpine for 48 h induced a 6-fold increase in NPY potency. Likewise, the potency of clonidine to inhibit the electrically induced muscular activity or noradrenaline to contract the ductus musculature was also potentiated. It is hypothesized that reserpine via a denervation super-sensitivity-like process increases the density of the NPY receptors. The functional significance of NPY in the motor activity of the vas deferens is discussed.     

Seasonal variations in the catecholamine concentration in the albino rat brain

Seasonal changes in the concentrations of dopamine (DA), noradrenalin (NA), and homovanillic acid (HVA) in the forebrain and diencaphalon were studied in 258 Wistar albino rats. Experiments were carried out montly for six years. The concentrations of DA, NA, and HVA in the brain changed significantly in the course of the year, and in both parts of the brain the changes were in the same direction. The DA concentration in the winter and spring months was higher than the average for the year, whereas in summer it was lower. The NA concentration was much higher in spring (by one-third in the diencephalon) than the mean values. In the summer months (June–August) the average NA concentration corresponded to more rapid metabolism of DA (a decrease in DA and an increase in HVA).Laboratory of Psychopharmacology and Department of Pharmacology, Tartu University. (Presented by Academician of the Academy of Medical Sciences of the USSR M. D. Mashkovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 2, pp. 215–217, February, 1980.     

Gene expression in the efferent ducts,epididymis, and vas deferens during embryonic development of the mouse

The tissues of the male reproductive tract are characterized by distinct morphologies, from highly coiled to un‐coiled. Global gene expression profiles of efferent ducts, epididymis, and vas deferens were generated from embryonic day 14.5 to postnatal day 1 as tissue‐specific morphologies emerge. Expression of homeobox genes, potential mediators of tissue‐specific morphological development, was assessed. Twenty homeobox genes were identified as either tissue‐enriched, developmentally regulated, or both. Additionally, ontology analysis demonstrated cell adhesion to be highly regulated along the length of the reproductive tract. Regulators of cell adhesion with variable expression between the three tissues were identified including Alcam, various cadherins, and multiple integrins. Immunofluorescence localization of the cell adhesion regulators POSTN and CDH2 demonstrated cell adhesion in the epithelium and mesenchyme of the epididymis may change throughout development. These results suggest cell adhesion may be modulated in a tissue‐specific manner, playing an important role in establishing each tissue's final morphology. Developmental Dynamics 239:2479–2491, 2010. © 2010 Wiley‐Liss, Inc.     

Contractile response and electrophysiological properties in enzymatically dispersed smooth muscle cells of rat vas deferens

Electrophysiological studies were performed on single smooth muscle cells isolated from the vas deferens of the rat. The tissue was preincubated in Ca-free modified Tyrode's solution for 1 h and then transferred to a high-K solution for 1 h. It was next minced and treated with the enzyme solution composed of 600–800 unit/ml collagenase and 40 unit/ml elastase. The procedure yielded about 50% spindle shaped Ca-tolerant cells (100–250 m in length and about 10 m in diameter). These cells could contract during the superfusion with the solutions containing 10^–8 to 10^–3M norepinephrine (NE) or adenosine triphosphate (ATP). The cells isolated from the epididymal portion were more sensitive to norepinephrine than were those from the prostatic part. Their basic electrical properties were studied using tight-seal suction electrode technique. The cells had resting potentials around –40 mV and their input resistance was about 0.8 G. Action potentials could be evoked by application of depolarizing current. During whole cell voltage clamp, an inward current followed by an outward current was recorded when 800 ms pulses from a holding potential of –60 mV to test potentials positive than –40 mV were applied. The transient outward current generally recorded in other smooth muscle cells was not seen in these cells. The amplitude of the inward current was Ca dependent and sensitive to a Ca antagonist, nicardipine, indicating that Ca ion is the main carrier of this component of the current. When the pipette was filled with Cs-containing solution, the outward current was abolished. In this condition, the reversal potential of Ca current was +53.4 mV, and the time course of inactivation was composed of more than one exponential component. The results suggest that these isolated cells retain many characteristics of analogous multicellular preparation and that they are a useful model of the postsynaptic properties in smooth muscle especially when studied electro-physiologically.     

Autoradiographic localization of [3H]buspirone binding sites in rat brain

In the C-neurons of rabbit nodose ganglion there is a persistent slow outward current at Vm levels positive to -80 mV. This current was detectable in Na+-free Ringer and disappeared in Ca2+-free medium. Therefore it may be the Ca2+-activated K+ current. This K+ current shows a unique time and voltage dependency, suggesting that it may have a regulatory role on the excitability of C-neurons. Two other types of current also observed in C-neurons were IQ- and IA-like currents. In A-neurons, however, a Ca2+-activated K+ current was not observed at all.     

Spontaneous accumulation of eosinophils and macrophages throughout the stroma of the epididymis and vas deferens in alymphoplasia (aly) mutant mice: I. A histological study

PROBLEM: The alymphoplasia (aly) mutation of mice causes the systemic absence of lymph nodes and Peyer's patches. Histopathological analysis has revealed that lymphocytes accumulate in some organs such as the salivary glands, lungs, kidneys, liver, and pancreas of homozygotes (aly/aly) but not heterozygotes (aly/ + ). However, the presence of lymphocytic accumulation in male reproductive tissues of aly/aly mice has not been reported. METHOD OF STUDY: The male reproductive organs of homozygous aly/aly, heterozygous aly/ +, and other immunodeficient mice bred in a specific pathogen-free state were histologically investigated. RESULTS: Testes, ductuli efferentes, prostates, coagulating glands, and seminal vesicles of homozygous aly/aly mice were free from any pathological accumulation of leukocytes. However, their epididymides and vasa deferentia exhibited massive infiltration by leukocytes, which were composed of eosinophils and macrophages. In all homozygotes examined, both eosinophils and macrophages were extensively observed throughout the stroma of the epididymis and vas deferens, but never within the epithelium or lumen of the ducts, with no parenchymal tissue damage. The accumulation of eosinophils was never found in nonreproductive organs. In aly/ + heterozygous mice and other immunodeficient mice, no pathological accumulation of leukocytes were noted. CONCLUSIONS: The accumulation of eosinophils and macrophages is specific to the epididymides and vasa deferentia of immunodeficient aly/aly homozygotes, although the pathogenesis remains unknown.     

Presynaptic histamine H2 receptors modulate the sympathetic nerve transmission in the isolated rat vas deferens; no role for H3-receptors

The modulatory activity mediated by histamine receptors on the sympathetic nerve transmission was investigated in the rat vas deferens. Agonists and antagonists acting at the different histamine receptor subtypes (H₁, H₂ and H₃) were tested on electrically-driven preparationsin vitro. Low-frequency stimulation (0.1 Hz) evoked muscle contractions almost completelysustained by ATP release, while at high-frequency stimulation (5–10 Hz) norepinephrine was mainly involved. The H₁ receptor agonists, pyridilethylamine and 2-(2 aminoethyl)thiazole, enhanced the electrically evoked twitch responses, but not contractions induced by exogenously-applied norepinephrine and ATP. These effects were prevented by the H₁-blocking drugs, mepyramine and phenyramine, but only at high concentrations (10 mol/l). All these H₁-antagonists strongly enhanced muscle response to electrical stimulation. The H₂ receptor agonists, dimaprit, amthamine and impromidine, reduced the contractions evoked by field stimulation, but not by exogenously applied norepinephrine and ATP, the effect being antagonised by H₂-blocking drugs, ranitidine and famotidine. The H₃ receptor agonist,R()-methylhistamine, reduced the electrically evoked muscle contractions, the effect being not modified by the selective H₃-blocking drug, thioperamide, but prevented by famotidine. These data suggest that rat vas deferens contains presynaptic histamine H₂ receptors, able to mediate inhibitory effects on the sympathetic transmission, while histamine H₃ receptors are apparently not involved. On the contrary, the role of H₁ is still unclear, since both agonists and antagonists may have the same effects.     

Effect of guinea-pig purified immunoglobulin G1 on the responsiveness of tracheal, aortic, vas deferens and ileum smooth muscles

Background Smooth muscles hyperresponsiveness is a common feature in anaphylaxis and allergic diseases. Objective The aim of the present work was to investigate the effect of in vitro passive sensitization with highly purified immunoglobulin GI (IgGl) on the responsiveness of tracheal, aortic, vas deferens and ileum smooth muscles. Method Firstly, IgGl, obtained from actively sensitized BFA guinea-pigs, was purified by Protein A-Sepharose column and characterized by enzyme-linked immunosorbent assay (ELISA) and immunoelectrophoresis analysis. Concentration-response curves to spasniogens (acelylcholine for trachea and vas deferens, noradrenaline for aorta and histamine for ileum) were established before and after in vitro passive sensitizalion with IgGl. Results Contractile responses and maximal contractions were significantly enhanced after passive sensitization for all the organs. Maximal contractions were significantly increased in the trachea (+46.7%), aorta (+51%), vas deferens (+114.2%) and ileum (+ 117.2%). At the end of the experiments, the application of the sensitizing antigen induced a significant Schultz-Dale reaction of the smooth muscles. Conclusion The present results show that the in vitro application of purified IgGl can produce non-specific smooth muscle hyperreactivity and hypersensitivity. So, IgGl can be considered as the main factor involved in the genesis of sensitization-induced hyperresponsiveness, and probably play a great role in hyperreactivity observed during allergic diseases and anaphylaxis.     

Influence of postweaning social isolation in the rat on brain development,conditioned behavior,and neurotransmission

There is substantial evidence that early life events influence brain development and subsequent adult behavior and play an important role in the causation of certain psychiatric disorders including schizophrenia and depression. The underlying mechanism of the effects of these early environmental factors is still not understood. It is a challenge to attempt to model early environmental factors in animals to gain understanding of the basic mechanisms that underlie the long-term effects. This paper reviews the effects of rearing rats from weaning in social isolation and reports some recent results indicating hippocampal dysfunction.Isolation rearing in rats from weaning produces a range of persistent behavioral changes in the young adult, including hyperactivity in response to novelty and amphetamine and altered responses to conditioning. These are associated with alterations in the central aminergic neurotransmitter functions in the mesolimbic areas and other brain regions. Isolation-reared rats have enhanced presynaptic dopamine (DA) and 5-HT function in the nucleus accumbens (NAC) associated with decreased presynaptic 5-HT function in the frontal cortex and hippocampus. Isolation-reared rats have reduced presynaptic noradrenergic function in the hippocampus, but have enhanced presynaptic DA function in the amygdala. These neurochemical imbalances may contribute to the exaggerated response of the isolated rat to a novel stimulus or to stimuli predictive of danger, and isolation-induced behavioral changes. These changes have neuroanatomical correlates, changes which seem to parallel to a certain degree those seen in human schizophrenia. A greater understanding of the processes that underlie these changes should improve our knowledge of how environmental events may alter brain development and function, and play a role in the development of neuropsychiatric disorders.     

Quantitative autoradiography of nicotinic [H]acetylcholine binding sites in rat brain

Quantitative autoradiography was used to localize nicotinic [³H]acetylcholine (ACh) binding sites in rat brain. High concentrations of nicotinic [³H]ACh binding sites were observed in the anterior and medial nuclei of the thalamus, the medial habenula and the superficial layer of the superior colliculus. Moderate levels of binding sites were observed in a variety of brain regions such as the frontoparietal cortex and the hippocampus. Low levels of nicotinic ACh sites occurred throughout the hypothalamus and the primary olfactory cortex.     

6-Hydroxydopamine induces degenerative changes in innervation of the rat pituitary gland

Administration of 6-hydroxydopamine to adult male rats by peripheral injections induces degenerative changes in nerve terminals innervating cells of the pituitary intermediate lobe. Additional animals were treated with 5-hydroxydopamine, which produced images of nerve profiles containing vesicles with electron-dense centers, indicative of uptake of the false catecholamine (CA) neurotransmitter. Endocrine cells showed cytologic evidence of activation of synthetic and secretory compartments. The ultrastructural observations suggest that innervation to opiomelanocortin cells is sensitive to a CA-specific neurotoxin and strengthens the hypothesis that CA-containing fibers play a role in intermediate lobe neuroregulation.     

Effect of adenosine and β-endorphin on contractions of the vas deferens of rats differing in predisposition to ethanol

Laboratory for the Search for and Study of Agents for Prevention and Treatment of Drug Addictions, Research Institute of Pharmacology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. V. Val'dman.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 108, No. 12, pp. 700–702, December, 1989.     

Zn2+-, Cu2+-containing superoxide dismutase in brain tissue of rat offspring exposed antenatally to alcohol

Laboratory of Brain Pathology, Research Institute of Psychiatry, Ministry of Health of the RSFSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR S. S. Debov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 111, No. 4, pp. 354–355, April, 1991.     

Fast and slowly inactivating components of Ca-channel current and their sensitivities to nicardipine in isolated smooth muscle cells from rat vas deferens

(1) Fast and slowly inactivating components of Ca-channel current were compared to clarify whether more than one type of Ca-channel exists in smooth muscle cells from rat vas deferens using the whole cell variant of the patch clamp technique. The pipette was filled with 150 mM Cs solution to eliminate outward current and Ba was used as the charge carrier for Ca-channel current. (2) When activated by a 5 s test pulse to 0 mV from a holding potential of −60 mV, the inactivation process of Ba-current was well fitted by the sum of two exponentials. The time constant of the faster inactivating component was 100–300 ms and that of the slower inactivating component was 1.5–3 s. Steadystate inactivation curves of the fast- and slow-components were very similar. (3) The inward current activated at 0 mV from −80 mV was inactivated faster than that from −30 mV. The voltage-dependencies of the peak current from holding potentials of −30 mV and −80 mV were similar. Both had voltage threshold at −30 mV and were maximal at +10 mV. (4) Low concentrations of nicardipine (10⁻⁹ to 10⁻⁷ M) preferentially inhibited the slow component while higher concentration (10⁻⁶ to 10⁻⁵ M) were required to block the fast component. The current activated from a holding potential of −30 mV was almost fully suppressed by 10⁻⁷ M nicardipine whereas that from −80 mV was blocked only slightly. The voltage dependencies of the peak currents before and during the superfusion with nicardipine (10⁻⁷ M) were similar although the peak amplitude was suppressed in the presence of the drug. (5) These results suggest that the existence of either (a) two populations of Ca channels that differ in the time course of inactivation and the sensitivity to nicardipine, but have nearly identical dependence on membrane potential or (b) one population of Ca channel having two different states of inactivation and the sensitivity of nicardipine, in rat vas deferens.     

Postnatal upregulation of alpha4 and alpha3 nicotinic receptor subunits in the brain of alpha7 nicotinic receptor-deficient mice

The nicotinic receptor subtypes are important for several physiological functions in brain and may therefore play a critical role in brain development. The alpha7 nicotinic receptors which have high Ca2+ permeability are important for cognitive, neuroprotective and trophic functions. In this study, the brain development and the expression of alpha4, alpha3, alpha7, alpha5 and beta2 nicotinic receptors were investigated in the brains of alpha7 deficient (alpha7 -/-), alpha7 heterozygous null (alpha7 +/-) and alpha7 wild-type (alpha7 +/+) mice from postnatal days (P) 7-84. The specific binding of [3H] cytisine and [3H] epibatidine, as well as the expressions of alpha4 and alpha3 nicotinic receptor subunits at mRNA and protein levels, were significantly increased in the cortex and hippocampus of alpha7 -/- and alpha7 +/- mice compared with alpha7 +/+ mice. Furthermore, the alpha4 and alpha3 nicotinic acetylcholine receptor (nAChR) subunits appeared to co-assemble with the alpha5 nAChR subunit in these above brain regions of these mice. No significant change in synaptophysin level was observed. These data suggest that increased levels of alpha4, alpha3-containing nAChRs, co-assembled with the alpha5 nAChR subunit, may contribute to the normal brain development of alpha7 -/- and alpha7 +/- mice.     

Enhancement of insulin secretion during selective blockade of alpha 1- and alpha 2-adrenoceptors in the rat: effects of somatostatin

The effects of somatostatin on plasma concentrations of insulin and glucose in the presence of the selective alpha 1-adrenoceptor blocking agent prazosin or the selective alpha 2-adrenoceptor blocking drug yohimbine were studied in vivo in anesthetized rats. Infusion of both prazosin (0.080 mg/min) and yohimbine (0.018 mg/min) increased plasma insulin levels within 10 min. Prazosin, but not yohimbine, caused a significant increment in plasma glucose concentrations during the infusion of both prazosin and yohimbine, suggesting that the inhibitory effect of somatostatin is not mediated via a direct action on alpha 1- or alpha 2-adrenoceptors. Plasma glucose concentration fell slightly during somatostatin administration. A marked increment in insulin release occurred in response to cessation of the somatostatin infusion, both during prazosin- and yohimbine-treatment. We conclude that somatostatin efficiently inhibits insulin secretion during selective alpha 1- and alpha 2-adrenoceptor blockade and, further, that the insulin off-response after somatostatin treatment is potentiated by alpha-adrenoceptor blockade. This study also indicates that blockade of alpha 1- as well as alpha 2-adrenoceptors leads to an increased insulin secretion.