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Central hypertonic NaCl increases cytokine expression in the hypothalamic paraventricular nucleus
Author(s) -
Shi Peng,
Dong Ying,
Shan Zhiying,
Lin Fan,
Raizada Mohan K,
Sumners Colin
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.809.8
Subject(s) - endocrinology , medicine , receptor , chemistry , angiotensin ii , tonicity , hypertonic saline , cytokine , angiotensin ii receptor type 1 , tumor necrosis factor alpha , hypothalamus
Recent studies indicate that brain‐derived cytokines are involved in sympathetic activation and hypertension. Our objective was to determine the relationship between hyperosmotic stimulus (HS), which enhances sympathetic outflow, and cytokine expression in the CNS. SD rats received an intracerebroventricular (ICV) injection of 2M NaCl (HS) or 0.9% NaCl, and 3 hours later PVN tissues were dissected for RT‐PCR analyses. PVN levels of interleukin (IL) 1β, IL6, IL10 and tumor necrosis factor α mRNAs were significantly increased in response to 2 M NaCl compared with the 0.9% NaCl treatment. Levels of CD11b mRNA, a marker of microglial activation, were also increased in the PVN of 2M NaCl injected rats. Pretreatment of rats with minocycline, an inhibitor of microglial activation, via s.c. infusion for 7 days, abolished the HS stimulated increase in IL1β, IL6 and CD11b expression. Angiotensin II type 1 (AT1) receptor mRNA levels were significantly increased by HS, and this response was abolished by minocycline. In summary, our data show that central administration of hypertonic NaCl increases expression of cytokines and AT1 receptors in the PVN, and these responses were completely inhibited by minocycline. This suggests that cytokines in the PVN are involved in the regulation of AT1 expression in response to hypertonic NaCl challenge. (NIH: HL33610 & HL76321 [M.K.R.], HL 076803 [C.S.]; AHA: 09POST2230164 [P.S.])