J Vet Sci.  2011 Sep;12(3):291-293. 10.4142/jvs.2011.12.3.291.

Differential brain angiotensin-II type I receptor expression in hypertensive rats

• Braga VA

• KMID: 1067403
• DOI: http://doi.org/10.4142/jvs.2011.12.3.291

Abstract

Blood-borne angiotensin-II (Ang-II) has profound effects in the brain. We tested the hypothesis that Ang-II-dependent hypertension involves differential Ang-II type I (AT1) receptors expression in the subfornical organ (SFO) and the rostral ventrolateral medulla (RVLM). Male Wistar rats were implanted with 14-day osmotic minipump filled with Ang-II (150 ng/kg/min) or saline. AT1 receptor mRNA levels were detected in the SFO and RVLM by reverse transcription-polymerase chain reaction (RT-PCR). Ang-II caused hypertension (134 +/- 10 mmHg vs. 98 +/- 9 mmHg, n = 9, p < 0.05). RT-PCR revealed that Ang-II infusion induced increased AT1 receptor mRNA levels in RVLM and decreased in SFO. Our data suggest that Ang-II-induced hypertension involves differential expression of brain AT1 receptors.

Keyword

blood pressure; losartan; rostral ventrolateral medulla; subfornical organ; sympathetic activity

MeSH Terms

Angiotensin II/*metabolism
Animals
Hypertension/chemically induced/*metabolism
Male
Medulla Oblongata/*metabolism
RNA, Messenger/genetics
Rats
Rats, Wistar
Receptor, Angiotensin, Type 1/*genetics
Reverse Transcriptase Polymerase Chain Reaction
Signal Transduction
Subfornical Organ/*metabolism

Figure

• 

  Fig. 1 Real time-PCR analysis at 14 days of angiotensin-II (Ang-II) infusion reveals down-regulation of Ang-II type I receptors (AT1 R) in the subfornical organ (A and B) and up-regulation of AT1 R in the rostral ventrolateral medulla (C and D). *p < 0.05, when compared to saline group (n = 3, biological samples; 5 rat per sample).

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