- 作者: Kellysan Powers-Martin; Anna M. Barron; Clare H. Auckland; John K. McCooke; Douglas J. McKitrick; Leonard F. Arnolda; Jacqueline K. Phillips
- 作者服務機構: Division of Health Sciences, School of Veterinary and Biomedical Science, Murdoch University, WA, Australia
- 中文摘要: --
- 英文摘要:
Functional evidence suggests that nitric oxide (NO) signalling in the rostral ventrolateral medulla (RVLM) is cGMP-dependent and that this pathway is impaired in hypertension. We examined cGMP expression as a marker of active NO signalling in the C1 region of the RVLM, comparing adult ([18 weeks) Wistar–Kyoto (WKY, n = 4) and spontaneously hypertensive rats (SHR, n = 4). Double label immunohistochemistry for cGMPimmunoreactivity (IR) and C1 neurons [as identified by phenylethanolamine N-methyltransferase (PNMT-IR) or tyrosine hydroxylase TH-IR)], or neuronal NO synthase (nNOS) neurones, failed to reveal cGMP-IR neurons in the RVLM of either strain, despite consistent detection of cGMP-IR in the nucleus ambiguus (NA). This was unchanged in the presence of isobutylmethylxanthine (IBMX; 0.5 mM, WKY, n = 4, SHR n = 2) and in young animals (WKY, 10-weeks, n = 3). Incubation of RVLMslices (WKY, 10-weeks, n = 9) in DETA-NO (100 lm; 10 min) or NMDA (10 lM; 2 min) did not uncover cGMPIR. In all studies, cGMP was prominent within the vasculature.
Soluble guanylate cyclase (sGC)-IR was found throughout neurones of the RVLM, but did not co-localise with PNMT, TH or nNOS-IR neurons (WKY, 10-weeks, n = 6). Results indicate that within the RVLM, cGMP is not detectable using immunohistochemistry in the basal state and cannot be elicited by phosphodiesterase inhibition, NMDA receptor stimulation or NO donor application. - 中文關鍵字: --
- 英文關鍵字: RVLM; Immunohistochemistry; Slice preparation; Nitric oxide; NMDA; C1 cell group