[The stress gene in hypertension].

Abstract

Thermosensitivity has been demonstrated in hypertensive rats and mice, and hypertension is frequent in hyperthermia-susceptible pigs. We have demonstrated that thermosensitivity segregates with hypertension in mice as a recessive trait in a single locus termed Tms. Since thermosensitivity can be demonstrated in cells obtained from neonatal hypertensive animals and persists after several passages in culture, it was of interest to study its cellular determinants. We undertook studies of candidate genes of cellular thermosensitivity, hsp70 being the major heat stress gene. First, we have observed an enhanced hsp70 mRNA accumulation in the hypertensive rat, mouse and human after heat shock of the whole animal, of its isolated organs or cultured cells. This increased accumulation of hsp70 mRNA in hypertension is due to its increased transcriptional rate. A restriction fragment length polymorphism (RFLP) of hsp70 was documented in hypertensive rats, which allowed the study of the segregation of this locus with hypertension in recombinant inbred strains of rats. At least one copy of hsp70 has been localized in RT1, the major histocompatibility complex of the rat, with polymorphism demonstrated with BamHI outside of the coding region of hsp70. This polymorphism segregates with 15 mmHg of systolic blood pressure. More recently, our studies led us to identify a polymorphism in another heat stress gene, hsp27. This polymorphism has been identified by PCR SSCP and is located in the 3' region, close to the termination translation codon.(ABSTRACT TRUNCATED AT 250 WORDS)