22Na+ and 86Rb+ transport in vascular smooth muscle of SHR, Wistar Kyoto, and Wistar rats.
To gain further insight into differences in cellular Na+ and K+ regulation between the spontaneously hypertensive rat (SHR), Wistar Kyoto (WKY), and American Wistar (W) rats, 22Na+ and 86Rb+ washouts were performed under steady-state conditions in cultured vascular smooth muscle cells from the three rat strains. SHR vascular smooth muscle cells showed significantly higher bumetanide sensitive 86Rb+ washout rate constant (x 10(-4)/min; mean +/- SEM) than WKY cells (-38.6 +/- 2.84 and -23.8 +/- 3.58, respectively; p less than 0.005). SHR vascular smooth muscle cells also exhibited significantly higher values than WKY cells in the total 22Na+ washout rate constant (x 10(-2)/min) (-61.0 +/- 1.57 vs. -53.8 +/- 1.24; p less than 0.005). The amiloride sensitive component of the 22Na+ washout rate constant accounted for these differences (-18.6 +/- 1.04 for SHR and -12.1 +/- 2.00 for WKY; p less than 0.05). There were no apparent differences in cellular Na+ concentrations between WKY and SHR cells. In general, the 86Rb+ and 22Na+ washout parameters of W rat cells were quite similar to those of cells from SHR. We conclude that the bumetanide-sensitive 86Rb+ washout (the Na+ K+-cotransport), the overall, and the amiloride-sensitive 22Na+ washout (the latter primarily represents the Na+/H+ antiport) are higher in SHR than WKY rat vascular smooth muscle cells. These findings indicate innate differences in cellular Na+ and K+ transport in vascular smooth muscle cells of the SHR and WKY rat. The mechanisms responsible for these differences are yet to be determined.
Kuriyama
S
S
Hypertension Research Center, New Jersey Medical School, Newark.
Denny
T N
TN
Aviv
A
A
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport; D066298:In Vitro Techniques; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains; D011921:Rats, Inbred WKY; D012413:Rubidium / Q000378:metabolism*; D012414:Rubidium Radioisotopes; D012964:Sodium / Q000378:metabolism*; D012979:Sodium Radioisotopes; D013045:Species Specificity
D012414:Rubidium Radioisotopes; D012979:Sodium Radioisotopes; D010042:Ouabain; D000584:Amiloride; D012964:Sodium; D012413:Rubidium