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  • 1
    Electronic Resource
    Electronic Resource
    Melbourne, Australia : Blackwell Science Pty
    Clinical and experimental pharmacology and physiology 26 (1999), S. 0 
    ISSN: 1440-1681
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: 1. The effect of external ATP on the membrane current was investigated in PC12 cells by whole-cell voltage-clamp techniques.2. Lower concentrations of ATP (1 or 10 μmol/L) induced only an inward current at 1 mmol/L EGTA in the K+ pipette solution, while higher concentrations of ATP (100 μmol/L and 1 mmol/L) induced an outward current following the inward current.3. Lowering the EGTA concentration in the pipette solution induced a larger outward current following ATP application. The membrane potential at which the outward current crossed with the control before ATP application was more negative at lower concentrations of EGTA in the pipette.4. The development of the outward current was blocked by a Ca2+-free external solution, 5 mmol/L tetraethylammonium and a Cs+ pipette solution instead of K+, indicating that the outward current was a Ca2+-activated K+ current.5. Charybdotoxin (0.1 μmol/L) and iberiotoxin (0.1 μmol/L), but not apamin (0.2 μmol/L) blocked the development of the outward current, indicating that the ATP-induced outward current is a BK-type Ca2+-activated K+ channel current and not the SK type.6. UTP had no effect on the membrane current, indicating that the ATP-induced current change was not mediated by P2u but by P2x purinoceptor.7. In conclusion, stimulation of P2x purinoceptors by ATP induces a Ca2+-permeable inward current that results in increases in intracellular Ca2+ concentrations and activation of a BK-type Ca2+-activated K+ current in PC12 cells.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1438-8359
    Keywords: Cervical sympathectomy ; Stellate ganglion block ; Adrenocorticotropic hormone ; Thyroid-stimulating hormone ; Growth hormone ; Prolactin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To examine the effects of bilateral cervical sympathectomy on the secretion of adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), growth hormone (GH), and prolactin (PRL), 18 male rats were divided into three groups: control (Cont), sham operation (Sham), and bilateral cervical sympathectomy (Symp). All rats were kept under a normal circadian rhythm for 2 weeks. Subsequently, blood was collected and plasma ACTH as well as serum TSH, GH, and PRL levels were measured. The difference in ACTH levels between the Cont and Sham groups was not significant, but ACTH levels in the Symp group were significantly higher than those in the other groups. The difference in TSH levels between the Cont and Sham groups was also not significant, but TSH levels in the Symp group were significantly lower than those in the Cont group. There were no statistically significant differences in GH and PRL levels among these groups. The present results suggest that cervical sympathectomy in the rat increases ACTH secretion and decreases TSH secretion in the pituitary. These effects seem to be due to a mildly increased secretion of melatonin in the pineal body that probably in turn increases corticotropin-releasing factor (CRF) secretion and decreases thyrotropin-releasing hormone (TRH) secretion in the hypothalamus. Extrapolation of these findings to humans suggests that longterm and repeated stellate ganglion block would affect the pituitary secretions of ACTH and TSH.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1438-8359
    Keywords: Cervical sympathectomy ; Stellate ganglion block ; Gonadotropin ; Testosterone ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To examine the effects of bilateral cervical sympathectomy on the secretion of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and testosterone (TS), 24 male rats were divided into four groups: control (C), light (L), sympathectomy (S), and light-sympathectomy (LS) groups. The C and S groups were kept under a 12-h light-dark cycle and the L and LS groups were kept under continuous light for 2 weeks. After 2 weeks, blood was collected and the rats were perfused with a fixative. GnRH neurons in the hypothalamus were stained immunohistochemically, and serum LH and TS levels were measured by radioimmunoassay. Although the difference in the number of GnRH neurons between the C and S groups was not significant, the L group was significantly lower than the C or LS groups. The serum LH and TS levels in the L group were higher than in the other groups. The present results suggest that continuous light increases GnRH secretion in the hypothalamus, followed by increased secretions of LH in the pituitary and TS in the testes, and bilateral cervical sympathectomy under continuous light inhibits these hormonal changes. However, a normal circadian rhythm does not affect gonadotropin secretion. Therefore, long-term and repeated stellate ganglion block may inhibit the increases of GnRH, LH, and TS secretions induced by continuous light.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of anesthesia 9 (1995), S. 363-365 
    ISSN: 1438-8359
    Keywords: Sevoflurane ; Halothane ; Enflurane ; Isoflurane ; Cesarean section
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1438-8359
    Keywords: Cervical sympathectomy ; Gonadotropin-releasing hormone ; Hypothalamus ; Median eminence ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To examine the effects of cervical sympathectomy on the transport of gonadotropin-releasing hormone (GnRH) between the hypothalamic neurons and the median eminence, 16 male rats were assigned into four groups: control (C), light (L), light-sympathectomy (LS), and light-colchicine (LC). The C group was kept under a normal circadian rhythm for 2 weeks, and the L group was kept under continuous exposure to light for the same period. The LS group underwent bilateral cervical sympathectomy before being kept under continuous light conditions for 2 weeks. The LC group received colchicine into the cerebral ventricle after being kept under continuous light for 12 days; subsequently, this group was also housed for 2 days under continous light. After these procedures, blood was collected and serum luteinizing hormone (LH) levels were measured. All rats were perfused with a fixative, and GnRH neurons around the anterior commissure, as well as GnRH fibers and granules in the median eminence, were stained immunohistochemically. The L group showed a decreased number of GnRH neurons, increased concentrations of GnRH fibers and granules, and an increased LH level; however, in the LS and LC groups, these changes were not seen. The response in the LS group resembled that in the LC group. Considering the action of colchicine, which inhibits axonal transport, it is suggested that cervical sympathectomy also inhibits axonal transports of GnRH between the GnRH neurons and the median eminence during continuous exposure to light.
    Type of Medium: Electronic Resource
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