Exogenous Ouabain Is Accumulated in the Adrenals and Mimics the Kinetics of Endogenous Digitalis-like Factor in Rats

Autor: Shigeto Morimoto, Akira Nishibe, Takeshi Nakahashi, Shoichi Kitano, Keisuke Fukuo, Atushi Hirotani, Osamu Yasuda, Toshio Ogihara
Rok vydání: 1998
Předmět:
Zdroj: Hypertension Research. 21:47-56
ISSN: 1348-4214
0916-9636
DOI: 10.1291/hypres.21.47
Popis: Ouabain has been isolated as an endogenous pathogenetic factor in salt-induced hypertension and has been shown to be rich in the adrenals. In this study, organ accumulation of orally administered [3H]- ouabain was examined in rats. Exogenous [3H]ouabain was accumulated in high levels in the adrenals, especially in the zona intermedia, and was not metabolized in the rat. Accumulated [3H]ouabain mimicked the movement of "endogenous" digitalis-like factor, since 1) the plasma [3H]ouabain level decreased in bilaterally adrenalectomized rats, 2) the plasma [3H]ouabain level increased accompanied by a decrease in [3H]ouabain content in the adrenals in reduced renal mass hypertensive rats, and 3) [3H]- ouabain levels in plasma and in the adrenals increased in spontaneously hypertensive rats, as compared with those in respective control animals. Moreover, the rat diet contained a relatively high amount of ouabain-like immunoreactivity (OLI), and the ratio of the [3H]ouabain content to OLI in each organ was comparable to that of the daily intake of dietary [3H]ouabain to OLI. Furthermore, high 3H-radioactivities were also observed in the adrenals of rats that ingested [3H]digoxin and [3H]digitoxin. These data suggest that exogenous ouabain, related cardiotonic glycosides of plant origin, or both accumulate in the adrenals and, at least in part, act as "endogenous" digitalis-like factor(s). (Hypertens Res 1998; 21: 47-56).
Databáze: OpenAIRE