Prescription Drugs 2 Go

The aim of the study was to analyze whether the proliferative effects of insulin in rat liver involve cross-signaling toward the epidermal growth factor receptor (EGFR) and whether this is mediated by insulin-induced hepatocyte swelling. Studies were performed in the perfused rat liver and in primary rat hepatocytes. Insulin (35 nmol/liter) induced phosphorylation of the EGFR at position Tyr845 and Tyr1173, but not at Tyr1045, suggesting that EGF is not involved in insulin-induced EGFR activation. Insulin-induced EGFR phosphorylation and subsequent ERK1/2 phosphorylation were sensitive to Bumetanide, indicating an involvement of …

Authors: West CA, Zhang Z, Ecker G, Masilamani SM
Pregnancy-mediated sodium (Na) retention is required to provide an increase in plasma volume for the growing fetus. The mechanisms responsible for this Na retention are not clear. We first used a targeted proteomics approach and found that there were no changes in the protein abundance compared to virgin rats of the beta or gamma ENaC, type 3 Na/H exchanger (NHE3), Bumetanide-sensitive cotransporter (NKCC2) or NaCl cotransporter (NCC) in mid- or late- pregnancy. In contrast, we observed marked increases …

In this study, we examined the effect of bicarbonate transporters on ammonium/ammonia uptake in the medullary thick ascending limb cell line ST-1. Cells were treated with 1 mm ouabain and 0.2 mm Bumetanide to minimize carrier-mediated NH4+ transport, and the intracellular accumulation of 14C-methylammonium/methylammonia (14C-MA) was determined. In CO2/HCO3[minus]-free solution, cells at normal pH briefly accumulated 14C-MA over 7 min and reached a plateau. In CO2/HCO3[minus] solution, however, cells markedly accumulated 14C-MA over the experimental period of 30 min. This CO2/HCO3[minus]-dependent accumulation was reduced by the bicarbonate transporter blocker, 4,4′-diisothiocyanatostilbene-2,2′-disulfonate …

J. Neurochem. (2010) 10.1111/j.1471-4159.2010.06862.x In the present study, we investigated changes of cytosolic Ca2+([Ca2+]cyt), endoplasmic reticulum Ca2+([Ca2+]ER) and mitochondrial Ca2+(Ca2+m) in astrocytes following oxygen/glucose deprivation and reoxygenation (OGD/REOX). Two hours OGD did not cause changes in [Ca2+]cyt, but led to a significant increase in [Ca2+]ER. The elevation in [Ca2+]ER continued and reached a peak level (130 ± 2 [mu]M) by 90 min REOX. An abrupt release of Ca2+ER occurred during 1.5[ndash]2.5 h REOX, which was accompanied with a delayed and sustained rise in [Ca2+]cyt. Moreover, Ca2+m content was increased significantly …

Authors: Haas BR, Sontheimer H
Malignant gliomas metastasize throughout the brain by infiltrative cell migration into peritumoral areas. Invading cells undergo profound changes in cell shape and volume as they navigate extracellular spaces along blood vessels and white matter tracts. Volume changes are aided by the concerted release of osmotically active ions, most notably K(+) and Cl(-). Their efflux through ion channels along with obligated water causes rapid cell shrinkage. Suitable ionic gradients must be established and maintained through the activity of ion transport systems. Here, we …

This study focuses on basolateral Cl– uptake mechanisms in native lungs of Xenopus laevis and the involvement of the Na+/K+/2 Cl– cotransporter (NKCC) and HCO3–/Cl– anion exchanger (AE), in particular. Western blot analysis and immunofluorescence staining revealed the expression of the NKCC protein in the Xenopus lung. Ussing chamber experiments demonstrated that the NKCC inhibitors (Bumetanide and furosemide) were ineffective at blocking the cotransporter under basal conditions, as well as under pharmacologically stimulated Cl–-secreting conditions (forskolin and chlorzoxazone application). However, functional evidence for the NKCC was detected by generating a …

Intestinal HCO3– secretion and NaCl absorption are essential for counteracting dehydration in marine teleost fish. We investigated how these two processes are coordinated in toadfish. HCO3– stimulated a luminal positive short-circuit current (Isc) in intestine mounted in Ussing chamber, bathed with the same saline solution on the external and internal sides of the epithelium. The Isc increased proportionally to the [HCO3–] in the bath up to 80 mM NaHCO3, and it did not occur when NaHCO3 was replaced with Na+-gluconate or with NaHCO3 in Cl–-free saline. HCO3– (20 mM) induced …

In conclusion, PAR1 and PAR2 both induced Cl– secretion in the mouse cecum. This secretion mediated by PAR1 probably occurred by activation of the receptor on the submucosal secretomotor neurons, resulting mainly in the release of tachykinins and activation of the neurokinin-1 receptor, and partly in the release of ACh and activation of the muscarinic and nicotinic receptors. On the other hand, PAR2-mediated Cl– secretion probably occurred by activating the receptor on the epithelial cells. A variety of proteases would induce fluid secretion mediated by PAR1 and PAR2 in the …

Authors: Gagnon K, Delpire E
Na-K-2Cl cotransport mediates the movement of two Cl(-) ions for one Na(+) and one K(+) ion. Under isosmotic conditions or SPAK/WNK4 activation, the NKCC1-mediated Cl(-) uptake in Xenopus laevis oocytes, as measured using (36)Cl, is twice the value of K(+) uptake, as determined using (86)Rb. Under hyperosmotic conditions, there is a significant activation of the Bumetanide-sensitive K(+) uptake with only a minimal increase in Bumetanide-sensitive Cl(-) uptake. This suggests that when stimulated by hypertonicity, the cotransporter mediates K(+)/K(+) and Cl(-)/Cl(-) exchange. Although …

Mucus secretion from individual tracheal glands in adult ferrets was studied with time-lapse optical imaging of mucus droplets under an oil layer. Density of functional glands (determined by responses to 1 µM carbachol) was 1.5 ± 0.3 per mm2 (n = 6). Secretion rates (in pl·min–1·gland–1) were as follows: 4.1 ± 0.7 basal (unstimulated; n = 27, 669 glands), 338 ± 70 to 10 µM forskolin (n = 8, 90 glands), 234 ± 13 to 1 µM VIP (n = 6, 57 glands), 183 ± 92 to 10 µM isoproterenol …