BACKGROUND Epithelial migration restores barrier function after superficial injury to any mucosa. The present study aimed to determine whether butyrate, important to colonic epithelial physiology in diverse ways, influences restoration of barrier function in the injured rat colon. METHODS Rat distal colon was transiently exposed in vitro to heat (55 degrees C for 10 sec) or to detergent (deox...

Acute lung injury (ALI) is characterized by the flooding of the alveolar airspaces with protein-rich edema fluid and diffuse alveolar damage. We have previously reported that transforming growth factor-beta1 (TGF-beta1) is a critical mediator of ALI after intratracheal administration of bleomycin or Escherichia coli endotoxin, at least in part due to effects on lung endothelial and alveolar epi...

Since the mechanism underlying the insulin stimulation of (Na+,K+)-ATPase transport activity observed in multiple tissues has remained undetermined, we have examined (Na+,K+)-ATPase transport activity (ouabain-sensitive 86Rb+ uptake) and Na+/H+ exchange transport (amiloride-sensitive 22Na+ influx) in differentiated BC3H-1 cultured myocytes as a model of insulin action in muscle. The active upta...

Pre-steady-state kinetic measurements of 22Na+ uptake by the amiloride-sensitive Na+-H+ exchanger in renal brush border membrane vesicles (BBMV) were performed at 0 degrees C to characterize the intermediate reactions of the exchange cycle. At 1 mM Na+, the initial time course of Na+ uptake was resolved into three separate components: (i) a lag phase, (ii) an exponential or "burst" phase, and (...

Exchange of intracellular sodium for extracellular lithium readily occurs in vascular smooth muscle, but the mechanism of this exchange is not known. These studies examined whether a sodium-lithium countertransport system was present in the cell membrane of vascular smooth muscle. A sarcolemmal-enriched vesicle preparation was obtained from canine superior mesenteric artery via a magnesium aggr...

BSC-1 kidney epithelial cells derived from the African green monkey are known to express a Na+HCO3- symport (Jentsch, T. J., Schill, B. S., Schwartz, P., Matthes, H., Keller, S. K., and Wiederholt, M. (1985) J. Biol. Chem. 260, 15554-15560). In the present work, 4,4-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS)-sensitive 22Na+ uptake into confluent monolayers of BSC-1 is measured in the pr...

The ablation of renal mass and institution of a high protein diet both lead to renal cortical hypertrophy and increased glomerular filtration rate (GFR). We studied Na+ transport in rat microvillus membrane vesicles isolated from uninephrectomized or sham operated rats fed 6% (low), 24% (standard), or 40% (high) protein diets. The feeding of high protein, as compared with low protein, was assoc...

The cellular mechanisms responsible for abnormalities in spontaneously hypertensive rat (SHR) vascular smooth muscle cell (VSMC) growth and vasoreactivity are not defined. Because Na+/H+ exchange, which we have previously demonstrated in cultured VSMC, plays an essential role in mediating growth factor responses, we hypothesized that abnormalities in SHR growth regulation might be reflected in ...