Time-related alterations in an endogenous digitalis-like factor in the development of DOCA-salt hypertension in rats.
Time-related alterations in a digitalis-like factor in urine were examined by means of cross-reactivity with an anti-digoxin antibody during the development of hypertension in DOCA-salt rats. Daily urinary sodium excretion was also measured. After hypertension had developed, plasma levels of the digitalis-like factor were determined by two methods: radioimmunoassay for digoxin and a receptor binding assay using 3H-ouabain and a rat brain synaptosomal protein. Urinary digoxin-like immunoreactivity increased gradually and significantly in the DOCA-salt rats as compared with that of sham-operated high-salt rats and normal-salt rats. Urinary sodium excretion was significantly higher in the DOCA-salt rats, and a significant correlation (r = 0.56, p less than 0.001) was observed between the daily urinary digoxin-like immunoreactivity and daily sodium excretion. In plasma, both digoxin-like immunoreactivity and ouabain-like binding activity were significantly higher in the DOCA-salt rats than in the other 2 groups. These results suggest that digitalis-like factor plays an important role in the development of hypertension in DOCA-salt rats.
Nakamura
T
T
Second Department of Internal Medicine, Gunma University School of Medicine, Maebashi, Japan.
Ichikawa
S
S
Sato
K
K
Tajima
Y
Y
Fujita
H
H
Murata
K
K
D000818:Animals; D001798:Blood Proteins / Q000652:urine*; D002298:Cardenolides; D003900:Desoxycorticosterone; D004077:Digoxin; D006973:Hypertension / Q000097:blood / Q000209:etiology / Q000652:urine*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011955:Receptors, Drug / Q000378:metabolism; D012503:Saponins; D012964:Sodium / Q000652:urine; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors; D013997:Time Factors
D001798:Blood Proteins; D002298:Cardenolides; D011955:Receptors, Drug; D012503:Saponins; C028996:cardiac glycoside receptors; C034504:digoxin-like factors; D003900:Desoxycorticosterone; D004077:Digoxin; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase