| Co-Investigator(Kenkyū-buntansha) |
KABASHIMA Narutoshi University of Occupational and Environmental Health Department of Physiology, Re, 医学部, 助手 (80279322)
UETA Yoichi University of Occupational and Environmental Health Department of Physiology, Le, 医学部, 講師 (10232745)
SHIBUYA Izumi University of Occupational and Environmental Health Department of Physiology, As, 医学部, 助教授 (50162649)
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| Research Abstract |
To elucidate the mechanism of immune signal transduction to the hypothalamic neuroendocrine cells, we have measured [Ca^2] _i and the membrane currents or membrane potentials in hypothalamic supraoptic nucleus (SON) neurons, and melanotrophs of the pituitary pars intermedia.
The results of the study are following :
1. Prostaglandin E_2 (PGE_2) excited more than 80% of SON neurons tested.
2. PGF_<2alpha> and the selective FP agonist, fluprostenol, mimicked the effects of PGE_2, whereas DP,EP,IP,TP agonists had little effect. Moreover, the EP1 antagonist, SC-51322 and EP/FP antagonist, ONO-NT-012, did not block the effects of PGE_2, whereas the latter antagonist blocked the effects of fluprostenol.
3. PGE_2 induced non-selective cation currents in isolated SON neurons, whereas interleukin-1beta (1L-1beta) had little effect.
4. PGE_2 inhibited spontaneous inhibitory postsynaptic currents in SON slice preparations, while it did not affect spontaneous excitatory postsynaptic currents.
5. PGE_2 induced [Ca_<2+>] _i rises in isolated SON neurons, whereas 1L-1beta did not have a direct effect.
6. PGE_2 inhibited voltage-dependent Ba^<2+> currents in rat melanotrophs through pertussis toxin sensitive G-proteins.
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