This study aimed to elucidate whether melatonin would exert beneficial effects on the neuronal functions of the nodose ganglion (NG) following acute hypoxic insult. The cytochrome oxidase (COX) and the nicotinamine adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry along with the nitric oxide synthase (NOS) immunofluorescence were used to examine the metabolic stage and nitric oxide production in nodose neurons respectively. Adult rats were injected intraperitoneally with melatonin at 5 or 100 mg/kg. Hypoxia was achieved by placing the rats into an altitude chamber (PO2 = 43 torr) for 4 hr. The results show that in normal untreated rats, nearly all and about 43% of the NG neurons displayed COX and NOS/NADPH-d reactivities with various staining intensities respectively. However, COX reactivity was drastically decreased while NOS/NADPH-d reactivity was significantly upregulated following hypoxia treatment. In melatonin pretreated rats, the hypoxia-induced reduction of COX reactivity was obviously prevented and the augmentation of NOS/NADPH-d reactivity was successfully suppressed. The deficit in the metabolic stage and the over-activation of NOS would contribute to the generation of oxidative stress. By effectively preventing the metabolic disruption, melatonin may have potential utility in therapeutic treatment of neuronal dysfunctions where oxidative stress is a participant.

No abstract

Although an acupuncture needle penetrates the skin, subcutaneous tissue, and underlying muscle, the most effective locus for the somatic acupoint on the needle path is not well established. We therefore investigated the sensory innervations of tissues in the needle path of the canine Shen-Shu point and evaluated their roles in initiating an acupunctural signal. Horseradish peroxidase solution was injected at all three levels within the acupoint. Only a few peroxidase-positive neurons were observed in the L1 dorsal root ganglion following intradermal injection. Following subcutaneous injection, peroxidase-labeled neurons were detected extending from spinal levels T10 to L2, with maximal labeling at T12 (46.3%). Approximately 95% of positive neurons were at spinal levels T11, T12, T13, and L1. As a result of an intramuscular injection, labeled neurons were observed at spinal levels T12 to L3, with most labeling occurring at L1 (39.9%). Approximately 95% of positive neurons were at spinal levels T13, L1, and L2. The results suggest that most afferent terminals are in the subcutaneous tissue rather than the muscular tissue, with an approximate ratio of 3.75:1. The data provide solid evidence that sensory innervation to a somatic acupoint is confined to a spinal segment and spatially organized, and we speculate that to cause a maximum effect, the centripetally transmitted signal from needling a somatic acupoint is spatio-segmental and divergently amplified.

Cordyceps sinensis (CS) is an Ascomycetes fungus parasitic to Lepidoptera larvae, and has long been used as medicine to treat many illnesses and promote longevity in Chinese society.1,2) Previous investigations have shown that CS has many pharmacological activities such as reducing mean arterial pressure, 3) preventing cholesterol deposition in aorta, 4) and inducing tumor programmed cell death. [5][6][7][8] Moreover, reports have also demonstrated that CS can suppress tumor cell growth, modulate immune response, [9][10][11] stimulate the activity of natural killer cells and macrophages with anti-inflammatory effect, 12,13) and inhibits rejection of organ transplants, which is possible that the effect of CS on the immune system is mediated via hormonal secretion by the adrenal cortex since its product, glucocorticoid, is a favorite candidate for immuno-suppression. 14) Indeed, it has been demonstrated that CS can promote sex hormones in Leydig cells in vitro and in vivo [15][16][17][18][19][20] and adrenal cells in vitro. 21) It is well known that adrenocorticotropin (ACTH) will bind to membrane receptor of adrenal cells to trigger steroidogenesis. 22) Aim of this study is to examine if CS would also induce in vivo effects on corticosterone production in mouse. In addition, it remains to be clarified whether CS fractions will also have the effect. Thus, mice were fed with CS and its fractions (F2 and F3) and the in vivo plasma corticosterone levels and weights of body and adrenal glands were determined in the present study. 3 H-Corticosterone was purchased from DuPont-New England Nuclear (Boston, MA, U.S.A.). Antiserum to corticosterone was a gift from Dr. Paulus S. Wang (National Yang-Ming University, Taipei, Taiwan). MATERIALS AND METHODS ChemicalsPreparation of CS Fractions One hundred grams of crude CS was extracted with 800 ml distilled water and shaken at 37 ЊC for 72 h. The solution was then centrifuged at 12000ϫg at 4 ЊC for 30 min to collect the pellet named fraction 3 (F3). The supernatant was applied in the G150 gel filtration column (3ϫ100 cm) with 50 mM CH 3 COONH 4 buffer at pH 6.0. Two peaks were collected; the first peak was designated F1 and the second peak, F2. The yield percentage of F1, F2, and F3 were 1.69%, 13.46%, and 84.85%, respectively. The main content of those CS fractions were F2 with water-soluble low molecular weight proteins and F3 with relatively poor water-soluble polysaccharides and proteins.Animals Male B6 (C57BL/6NCrj) mice, 4-5 weeks old, were purchased form NCKUAC (National Cheng Kong University Animal Center). All animals were housed in groups of 4-6 in 29ϫ18ϫ13-cm polyethylene cages. The animal room was maintained at 22-24 ЊC on a 12 : 12 h light : dark cycle. Purina mouse chow (Ralston-Purina, St. Louis, MO, U.S.A.) and water were always available. Animals were randomly divided into three groups, at least 5 in each group, with the infusions of water, 0.02 or 0.2 mg/gbody weight of CS, F2 or F3, respectively, for 1, 3 or 7 d. The age at the beginning of experiment was 5 w...

We employed experimental degeneration, tract-tracing with wheatgerm agglutinin conjugated with horseradish peroxidase (WGA-HRP) and electron microscopy to explore the postganglionic sympathetic fibers in the hypoglossal nerve of hamsters. Quantitative results of normal untreated animals at the electron microscopic level showed the existence of unmyelinated fibers, which made up about 20% of the total fibers in the nerve, being more numerous on the left side. The nerve fibers were preferentially distributed at the periphery of the nerve. Following superior cervical ganglionectomy, most of the unmyelinated fibers underwent degenerative changes. Tract-tracing studies showed that some of the unmyelinated fibers were labeled by WGA-HRP injected into the superior cervical ganglion (SCG). It is suggested that the unmyelinated fibers represent the postganglionic sympathetic fibers originated from the SCG.