The mechanism of insulin stimulation of (Na+,K+)-ATPase transport activity in muscle.

Insulin stimulates the translocation of Na+/K+-dependent ATPase molecules from intracellular stores to the plasma membrane in frog skeletal muscle

“…Insulin is known to stimulate Na+/K+ transport in various tissue cells [3,4,[5][6][7][8][9][10][11][12][13][21][22][23][24]. However, the mechanisms by which insulin acts upon Na+/K+ transport systems have not been established.…”

“…However, the mechanisms by which insulin acts upon Na+/K+ transport systems have not been established. A number of hypotheses have been reported, such as (1) insulin elevates the affinity of Na+/K+ pumps to Na+ in muscles [5,8,9]; (2) insulin stimulates the unmasking of inactive Na+/K+ pump sites in muscles [7]; and (3) insulin stimulates amiloride-sensitive Na+/H+ exchange and the increased internal Na+ concentration activates Na+/K+ pumps in cultured myocytes [10] and hepatocytes [22]. The hypothesis that insulin exerts its effect through a rise in the internal Na+ concentration may be ruled out, since the intracellular Na+ concentration of skeletal muscle is known to shift to a lower level when the muscle is incubated with insulin [5], and the stimulatory effect of insulin on Na+/K+ transport is not suppressed by amiloride in intact rat skeletal muscles [13].…”

“…The relationship between transport activities and ionic concentrations [1], the inhibition of the activity by cardiac glycoside [2] and its hormonal regulation [3,4] have been studied extensively. In skeletal muscle cells, insulin has been reported to stimulate Na+/K+ transport [3][4][5][6][7][8][9][10][11][12][13], as well as having a facilitating effect on glucose and amino acid transport. In the previous studies [11,12], we reported that the Na+/K+-ATPase activity of a plasma membrane fraction prepared from muscles exposed to insulin was 1.8-fold higher than that in the corresponding fraction obtained from control muscles.…”

Effects of profound acidemia on the dynamic glucose and insulin response and plasma potassium and phosphorus concentrations during an intravenous glucose tolerance test in neonatal calves

“…Insulin-stimulated glucose uptake is mediated by the facilitative glucose transporter GLUT4, which is translocated to the plasma membrane in insulin-sensitive tissues (Gumà et al, 1995;Duhlmeier et al, 2005). Insulin-stimulated potassium uptake is mediated by activation of the Na + /K + -ATPase, which was reported to be further enhanced by an increased intracellular sodium flux (Rosic et al, 1985;Hundal et al, 1992). Insulin-stimulated phosphorus uptake is mediated by insulin-dependent upregulation of Na/P i co-transporter gene expression (Li et al, 1996).…”

Η Δράση Της Ινσουλίνης Στη Σύσπαση Των Λείων Μυϊκών Ινών Των Αεραγωγών

“…Έχουν πραγματοποιηθεί πάρα πολλές μελέτες όσον αφορά τη δράση της ινσουλίνης στους λείους μύες, κυρίως αγγείων. Έχει βρεθεί ότι η ινσουλίνη διεγείρει τη δραστηριότητα της Na + /K + ATPασης[89][90][91] . Η διέγερση της Na + /K + ATPασης, με την ανταλλαγή τριών ενδοκυττάριων ιόντων καλίου με δύο εξωκυττάρια ιόντα νατρίου, έχει σαν αποτέλεσμα την υπερπόλωση της κυτταρικής μεμβράνης.…”