A greater stimulation of Na-H antiport in cultured vascular smooth muscle cells by serum from spontaneously hypertensive rats.
We investigated the influence of serum from spontaneously hypertensive rats (SHR) on the Na-H antiport and Na-K pump activity of cultured vascular smooth muscle cells (VSMC). Subjecting the VSMC to rat serum stimulated the ouabain-sensitive 86Rb uptake. This activation of the Na-K pump was significantly greater with the SHR serum than the Wistar-Kyoto rat (WKY) serum. Furthermore, the serum from SHR exhibited a larger Na uptake in the presence of ouabain than that from WKY. A greater 5-(N,N-hexamethylene) amiloride-sensitive Na uptake accounted for this difference. When the Na-K pump was active, serum from either of the two strains did not cause an increase in intracellular Na concentrations. We concluded that serum from SHR produced a more pronounced activation of both the Na-H antiport and the Na-K pump. The study suggests that there are humoral factors in SHR serum which elicit the stimulation of the Na-H antiport, leading to the activation of the Na-K pump of VSMC.
Kuriyama
S
S
Second Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan.
Kaguchi
Y
Y
Nakamura
K
K
Hashimoto
T
T
Sakai
O
O
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D002352:Carrier Proteins / Q000378:metabolism / Q000502:physiology*; D002478:Cells, Cultured; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000493:pharmacokinetics; D051381:Rats; D011918:Rats, Inbred SHR / Q000097:blood*; D011921:Rats, Inbred WKY; D012413:Rubidium / Q000493:pharmacokinetics; D012964:Sodium / Q000493:pharmacokinetics; D017923:Sodium-Hydrogen Exchangers; D000254:Sodium-Potassium-Exchanging ATPase / Q000502:physiology
D002352:Carrier Proteins; D017923:Sodium-Hydrogen Exchangers; D010042:Ouabain; D000584:Amiloride; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D012413:Rubidium; D011188:Potassium