AT1-Receptors and Cellular Actions of Angiotensin II in Neuronal Cultures of Stroke Prone-Spontaneously Hypertensive Rat Brain
AT1 preceptors, its mRNA and cellular actions of angiotensin II (Ang II) have been compared between neuronal cultures of Wistar Kyoto (WKY) and stroke-prone spontaneously hypertensive (SP-SH) rat brains. Bmax for AT1-receptor binding is 2-fold higher and is associated with a parallel increase in the levels of AT1 preceptor mRNA in SP-SH rat brain neurons compared with WKY rat brain neurons. Ang II causes stimulation of both c-fos and norepinephrine transporter (NET) mRNAs in both strains of neurons and this stimulation is also 2–3-fold higher in SP-SH rat brain neurons compared with WKY rat brain neurons. In contrast, Ang II stimulation of PAI-1 mRNA in SP-SH neurons is only 50% that of in WKY rat brain neurons suggesting that SP-SH neurons express a decrease in AT1-receptor coupling with PAI-1 response. These observations demonstrate that SP-SH neurons express AT1-receptor-functions similar to those described for SHR neurons.
KeywordsLosartan Potassium Receptor Gene Expression Spontaneously Hypertensive Sustained Antihypertensive Effect Ofplasminogen Activator
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- 1.Saavedra, J.M., 1992, Brain and pituitary angiotensin, Endocrine Rev. 13: 329–380.Google Scholar
- 4.Raizada, M.K., Lu, D., and Sumners, C., 1994, AT1-receptors and angiotensin actions in the brain and neuronal cultures of normotensive and hypertensive rats, In: Current concepts: Tissue renin-angiotensin system as local regulators in Reproductive and Endocrine Organs, (Plenum Press, New York), pp. 331–348.Google Scholar
- 15.Sumners, C., and Raizada, M.K., 1993, In: Cellular and molecular biology of renin-angiotensin system, (CRC Press, Boca Raton, FL), pp. 379–411.Google Scholar
- 17.Sumners, C., Tang, W., Zelezna, B., and Raizada, M.K., 1991, Angiotensin II receptor subtypes are coupled with distinct signal transduction mechanisms in neurons and astroglia from rat brain, Proc. Natl. Acad. Sci. USA SS7567-7571.Google Scholar
- 20.Wang, A.M., Doyle, M.V., and Mark, D.F., 1989, Quantitation of mRNA by the Polymerase chain reaction, Proc. Natl. Acad. Sci. USA 86: 9719–9721.Google Scholar
- 21.Zelezna, B., Rydzewski, B., Lu, D., Olson, J.A., Shiverick, K.T., Tang, W., Sumners, C., and Raizada, M.K., 1992, Angiotensin II induction of Plasminogen activator inhibitor-1 gene expression in astroglial cells of normotensive and spontaneously hypertensive rat brain, Mol. Endocrinol. 6: 2009–2017.PubMedCrossRefGoogle Scholar
- 22.Raizada, M.K., and Lu, D., 1995, Angiotensin II (AII) stimulation of norepinephrine transporter (NET) gene expression in neuronal cultures in normotensive and spontaneously hypertensive (SH) rat brain (abstr), FASEB J. part I: A90.Google Scholar
- 23.Yu, K., and Raizada, M.K., 1995, Angiotensin II (AII) stimulation of Plasminogen activator inhibitor-1 (PAI-1) gene expression in neuronal cultures (NC) of normotensive (WKY) and spontaneously hypertensive (SH) rat brains (abstr), FASEB J. part I: A90.Google Scholar