Hypertension in human is one of the risk factors to stroke, heart attack, heart failure and arterial aneurism. Hypertension can be lowered by consuming antihypertensive drugs.

The genetic therapy by using siRNA (small interfering RNA) needs to develop to influence blood pressure (BP) regulation by reducing BP to normotensive. One of the blood plasma protein which is the factor of BP regulation is angiotensinogen.

It is the target of gene therapy of this research. The objective of the research is to know the effect of angiotensinogen siRNA injected intravenously on the decrease of rat BP.

siRNA consists of double heliks of RNA, less than 30 nucleotides and has 2 overhang nucleotides on each 3’ end. siRNA was designed due to angiotensinogen mRNA sequence of Rattus norvegicus, obtained from NCBI (National Center of Biotechnology Information) by BLAST (Local Allignment Search Tool) and from Invitrogen (Block-iTTM RNAi Designer, www.

rnaidesigner. invitrogen.

com/rnaiexpress) to get the specific siRNA design. The research was done on 15 male normotensive rats and 15 male spontaneously hypertensive rats (SHR) (National Bioresource for the Rat, Kyoto University-Japan).

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