Cosegregation of the Renin Gene With an Increase in Mean Arterial Blood Pressure in the F₂ Rats of SHR-WKY Cross¹

Abstract

Using the restriction endonuclease, Bgl I, Samani et al. found a restriction fragment length polymorphism (RFLP) for the renin gene in spontaneously hypertensive rats (SHR) and its normotensive control Wistar-Kyoto (WKY) rats (1). This RFLP was confirmed in our laboratory in SHR and WKY rats using a rat renin cDNA probe. The correlation of blood pressure and the renin RFLP was examined in 106 F₂rats produced from F₁ rats, the offspring of a cross between SHR males and WKY females. Systolic blood pressure was measured by the tail cuff method at 12 weeks of age. Mean arterial blood pressure of anesthetized rats was measured by cannuiation of the fomoral artery prior to sacrifice. The frequency of renin genotype showed a typical 1:2:1 Mendelian ratio in F₂ rats of SHR and WKY cross. The mean arterial blood pressure of F₂ rats homozygous with the SHR allele was significantly higher than F₂ rats that were heterozygous or homozygous for the WKY allele. No significant difference in systolic blood pressure was observed in these F₂ rats. Thus, the renin gene RFLP cosegregates with an increase in mean arterial blood pressure in the F₂ rats of SHR and WKY cross.

Key Words:

• Renin RFLP
• SHR
• cosegregation