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1.
Depolarization and muscarinic excitation induced in a sympathetic ganglion by vasoactive intestinal polypeptide 总被引：2，自引：0，他引：2
The effects of vasoactive intestinal polypeptide (VIP) in the superior cervical ganglion of the cat were studied in vitro and in vivo with sucrose gap and multiunit recording, respectively. At a dose of 0.03 to 0.12 nanomole, VIP produced a dose-dependent, prolonged (3 to 15 minutes) depolarization of the ganglion and enhanced the ganglionic depolarization elicited by the muscarinic agonist acetyl-beta-methylcholine. At a dose of 1.8 to 10 nanomoles, the peptide enhanced and prolonged the postganglionic discharge elicited by acetyl-beta-methylcholine, enhanced muscarinic transmission in ganglia treated with an anticholinesterase agent, and enhanced the late muscarinic discharge elicited by acetylcholine. VIP did not affect the early nicotinic discharge elicited by acetylcholine or by electrical stimulation of the preganglionic nerve. It is concluded that VIP has a selective facilitatory action on muscarinic excitatory mechanisms in the superior cervical ganglion of the cat. 相似文献
2.
Nerve growth factor attenuates neurotoxic effects of taxol on spinal cord-ganglion explants from fetal mice 总被引：3，自引：0，他引：3
Most neurons in organotypic cultures of dorsal root ganglia from 13-day-old fetal mice require high concentrations of nerve growth factor for survival during the first week after explanation. These nerve growth factor-enhanced sensory neurons mature and innervate the dorsal regions of attached spinal cord tissue even after the removal of exogenous growth factor after 4 days. In cultures exposed for 4 days to nerve growth factor and taxol (a plant alkaloid that promotes the assembly of microtubules) and returned to medium without growth factor, greater than 95 percent of the ganglionic neurons degenerated and the spinal cord tissues were reduced almost to monolayers. In contrast, when the recovery medium was supplemented with nerve growth factor, the ganglionic neurons and dorsal (but not ventral) cord tissue survived remarkably well. Dorsal cord neurons do not normally require an input from dorsal root ganglia for long-term maintenance in vitro, but during and after taxol exposure they become dependent for survival and recovery on the presence of neurite projections from nerve growth-factor-enhanced dorsal root ganglia. 相似文献
3.
Latent ganglionic infection with herpes simplex virus types 1 and 2: viral reactivation in vivo after neurectomy 总被引：32，自引：0，他引：32
Inoculation of the cornea, lip, or footpad of mice with herpes simplex virus type 1 resulted in a latent infection of the local sensory ganglia. Inoculation of the vagina and cervix with herpes simplex virus type 2, as well as type 1, also induced a latent ganglionic infection. With the use of sciatic nerve section as a stimulus, a reproducible model of viral reactivation in vivo was established. 相似文献
4.
The effects of pretreatment with iproniazid on the toxicity and cataract-producing ability of epinephrine and norepinephrine were studied. The epinephrine and norepinephrine were administered in such a way that a slow, prolonged rate of absorption was achieved. Under these conditions, the lethality and cataract-producing ability of these amines were shown to be significantly enhanced by the action of iproniazid. 相似文献
5.
Vaccinia virus recombinant expressing herpes simplex virus type 1 glycoprotein D prevents latent herpes in mice 总被引：28，自引：0，他引：28
K J Cremer M Mackett C Wohlenberg A L Notkins B Moss 《Science (New York, N.Y.)》1985,228(4700):737-740
In humans, herpes simplex virus causes a primary infection and then often a latent ganglionic infection that persists for life. Because these latent infections can recur periodically, vaccines are needed that can protect against both primary and latent herpes simplex infections. Infectious vaccinia virus recombinants that contain the herpes simplex virus type 1 (HSV-1) glycoprotein D gene under control of defined early or late vaccinia virus promoters were constructed. Tissue culture cells infected with these recombinant viruses synthesized a glycosylated protein that had the same mass (60,000 daltons) as the glycoprotein D produced by HSV-1. Immunization of mice with one of these recombinant viruses by intradermal, subcutaneous, or intraperitoneal routes resulted in the production of antibodies that neutralized HSV-1 and protected the mice against subsequent lethal challenge with HSV-1 or HSV-2. Immunization with the recombinant virus also protected the majority of the mice against the development of a latent HSV-1 infection of the trigeminal ganglia. This is the first demonstration that a genetically engineered vaccine can prevent the development of latency. 相似文献
6.
Infusion of angiotensin or renin in small quantities affects the sympathetic nervous system so that responses are increased to either drugs or reflexes that cause release of norepinephrine at nerve endings. Response to injected norepinephrine is relatively unchanged. This action of angiotensin is dependent upon an intact sympathetic nervous system. The direct vasoconstrictor action of angiotensin is not an essential part of the enhanced response. The phenomenon was shown to have relevance to acute and chronic experimental renal hypertension in dogs by the fact that in both the pressor response to tyramine was enhanced. We believe that the ability of angiotensin to intensify the effect of normal neurogenic vasomotor activity, along with an upward reset of the carotid sinus buffer mechanism, might account importantly for the neurogenic component of renal hypertension. 相似文献
7.
Light-enhanced free radical formation and trypanocidal action of gentian violet (crystal violet) 总被引：2，自引：0，他引：2
R Docampo S N Moreno R P Muniz F S Cruz R P Mason 《Science (New York, N.Y.)》1983,220(4603):1292-1295
Transmission of Chagas' disease by transfusion of blood containing Trypanosoma cruzi has often been reported, and gentian violet, a triarylmethane dye, is widely used by blood banks in attempts to eliminate such transmission. In a study of intact trypanosomes, gentian violet was found to undergo a one-electron reduction to produce a carbon-centered free radical as demonstrated by electron spin resonance spectroscopy. Either reduced nicotinamide adenine dinucleotide or the reduced dinucleotide phosphate could serve as a source of reducing equivalents for the production of this free radical by homogenates of Trypanosoma cruzi. The formation of this free radical, and the trypanocidal action of gentian violet, were enhanced by light. The enhanced free radical formation may be the basic cause of the selective toxicity of gentian violet to Trypanosoma cruzi. 相似文献
8.
Thermoregulation: effects of environmental temperature on turnover of hypothalamic norepinephrine 总被引：2，自引：0，他引：2
The hypothesis that norepinephrine is a transmitter in the temperature regulating center of the hypothalamus is based on observations of changes in the rectal temperatures of animals after injections of norepinephrine into the hypothalamus. By introducing tritiated norepinephrine as a label into the endogenous norepinephrine stores in the brain and then measuring the disappearance of tritiated norepinephrine from discrete areas, one can monitor the activity of norepinephrine-containing neurons in those areas. In the rat exposed to heat, the turnover of endogenous norepinephrine appears to be increased selectively in the hypothalamus, whereas exposure to cold has no effect. 相似文献
9.
Adenyl cyclase activity in rat pineal gland: effects of chronic denervation and norepinephrine 总被引：7，自引：0，他引：7
Adenyl cyclase activity in the pineal gland of rats was determined by measuring the rate of formation of radioactive cyclic 3',5'-adenosine monophosphate from (14)C-labeled adenosine triphosphate. Norepinephrine added in vitro to pineal homogenates enhanced this activity, while denervation of the pineal gland by superior cervical ganglionectomy did not significantly reduce it. The enzyme in these denervated glands was more responsive to the stimulatory effects of norepinephrine. 相似文献
10.
Systemic ethanol: selective enhancement of responses to acetylcholine and somatostatin in hippocampus 总被引：4，自引：0，他引：4
In rat hippocampal pyramidal cells tested in situ by iontophoresis of several neurotransmitters, ethanol significantly enhanced excitatory responses to acetylcholine and inhibitory responses to somatostatin-14 but had no statistically significant effect on excitatory responses to glutamate or inhibitory responses to gamma-aminobutyric acid or, in preliminary tests, to norepinephrine or serotonin. The effects of ethanol on responses to acetylcholine and somatostatin-14 may provide insight into synaptic mechanisms underlying the behavioral consequences of ethanol intoxication. 相似文献
11.
Proportional release of norepinephrine and dopamine- -hydroxylase from sympathetic nerves 总被引：13，自引：0，他引：13
R M Weinshilboum N B Thoa D G Johnson I J Kopin J Axelrod 《Science (New York, N.Y.)》1971,174(16):1349-1351
Dopamine-beta-hydroxylase(DBH), the enzyme that catalyzes the conversion of dopamine to norepinephrine, is localized in the vesicles containing catecholamine in sympathetic nerves. This enzyme is released with norepinephrine when the nerves to the guinea pig vas deferens are stimulated in vitro, and the amount of enzyme discharged increases as the length of stimulation periods increases. The amount of DBH released is proportional to the amount of norepinephrine released, and the ratio of norepinephrine to DBH discharged into the incubation medium is similar to that in the soluble portion of the contents of the synaptic vesicles from the vas deferens. These data are compatible with the release of the neurotransmitter norepinephrine and DBH from symnpathetic nerves by a process of exocytosis. 相似文献
12.
Norepinephrine turnover and metabolism in rat brain after long-term administration of imipramine 总被引：3，自引：0，他引：3
The rate of disappearance of intracisternally administered tritiated norepinephrine from rat brain is decreased after a single dose of the tricyclic antidepressant imipramine. During long-term administration of imipramine, however, the rate of disappearance of tritiated norepinephrine from brain gradually increases, and there is a concurrent decrease in the content of endogenous norepinephrine in brain. These findings may help to explain why antidepressant effects are observed clinically only after long-termn treatment with imipramine. 相似文献
13.
红参粉末中发现含有田七氨酸(β-N-oxalo-L-α,β-diaminopropionic acid)又名三七素,该物质是应用离子交换凝胶色谱柱(CM—Sephadex C—25)和快速蛋白质液相色谱柱(FPLCMono Q)分离得到的。我们检查了田七氨酸对豚鼠主动脉收缩作用的影响,在没有组胺或肾上腺素存在的条件卜,既无收缩作用也无松弛作用,它能增益组胺诱导豚鼠主动脉的收缩;但对于肾上腺素却无作用。此外,田七氨酸通过肾上腺素、ADP凝血酶和胶原,均无诱导血小板聚集的作用。田七氨酸对于血管紧张素转换酶也无阻抑作用。 相似文献
14.
SPECTOR S SJOERDSMA A ZALTZMAN-NIRENBERG P LEVITT M UDENFRIEND S 《Science (New York, N.Y.)》1963,139(3561):1299-1301
The isolated, perfused guinea pig heart contains all the catalysts required to form norepinephrine from the dietary precursor, tyrosine. The conversion of tyrosine-C(14) to norepinephrine in the perfused heart occurred at a rate comparable to that estimated for this conversion in vivo. To account for the maintenance of norepinephrine stores in the normal heart, it is not necessary to postulate that the hormone is extracted from the blood. 相似文献
15.
Brain norepinephrine: enhanced turnover after rubidium treatment 总被引：4，自引：0，他引：4
After biosynthesis of norepinephrine was inhibited, treatment of rats for 10 days with rubidium chloride (0.6 milliequivalent per kilogram of body weight) caused an increase in the rate of disappearance of norepinephrine in the brainstem but not in the telencephalon. Also the utilization of intracisternally injected tritiated norepinephrine was increased and was accompanied by a shift in the pattern of norepinephrine metabolism to normetanephrine. These data suggest that greater amounts of neuronally stored norepinephrine were released to central adrenergic receptors. 相似文献
16.
Systemically administered flunarizine enhanced neuronal survival in lumbar sensory ganglia in newborn rats after axotomy. Flunarizine-treated rats lost 71 percent fewer neurons than the untreated control rats at the end of 1 week. In cell culture, flunarizine at 30 to 40 microM also prevented neuronal death in nerve growth factor-dependent embryonic sensory and sympathetic neurons after the abrupt withdrawal of neurotrophic support. The drug may cause this effect by acting at an intracellular site, one distinct from its blockade of voltage-dependent calcium channels. 相似文献
17.
Physiological variation in alpha-adrenoceptor-mediated arterial sensitivity: relation to agonist affinity 总被引：3，自引：0，他引：3
Vascular smooth muscle from different arteries of the rabbit varies in sensitivity to norepinephrine, even when factors known to contribute to this variation are excluded. Sensitivity to norepinephrine mediated through the alpha-adrenoceptor is linearly related to the agonist dissociation constant, but is not significantly related to receptor reserve. These results suggest that agonist affinity is the primary determinant of sensitivity to norepinephrine, at least in these arteries, and that this is a locally regulated characteristic which may account for regional sensitivity changes. 相似文献
18.
将HRP注入食管两侧壁,在两侧结状节出现大量的标记细胞。在颈1—8和胸1—6脊神经节中出现标记细胞,以颈2—6和胸1—3节中标记细胞较多,但标记细胞最多的节是颈6和胸2。脊神经节中的大、中标记细胞相对多于结状节。根据计数,结状节中标记细胞占总数的63.7％,而脊神经节占36.3％,即食管的感觉经由迷走神经传入占优势。 相似文献
19.
The rate of disappearance of intracisternally administered [(3)H]norepinephrine from rat brain gradually declines as a multiphasic exponential function of time. Conversion to [(3)H]normetanephrine accounts for a larger fraction of the [(3)H]norepinephrine released in the brain shortly after its intracisternal injection than that released at later times. Pools of norepinephrine in the brain thus appear to differ in their turnover rates and pathways of metabolism. The pool of norepinephrine with a rapid rate of turnover and an appreciable conversion to normetanephrine, identified by the techniques reported here, may correspond to a pool of newly synthesized norepinephrine in the brain. 相似文献
20.
ＰＰ３３３处理可使小麦叶片的表皮细胞、保卫细胞和叶肉细胞体积显著减少;增加叶片内叶肉细胞的层数和叶脉的机械组织的细胞层数,并可加强叶肉细胞的环型结构,使叶肉细胞之间的排列更加紧密。ＰＰ３３３处理对小麦叶片内叶绿体超微结构的影响表现为叶绿体内基粒数明显增多,高片层垛叠的基粒数比例增加,基质片层较为完善,基质内电子密度较浓,类囊体膜系统的发育进程明显加快。ＰＰ３３３处理可显著提高叶片的叶绿素含量,增加叶片的净光合速率,并延长叶片的光合功能期。 相似文献