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Ischemia-induced brain edema formation is mediated by increased transport of Na and Cl across an intact blood-brain barrier (BBB). Our previous studies have provided evidence that a luminally located BBB Na-K-Cl cotransporter is stimulated during cerebral ischemia to increase transport of Na and Cl into the brain. The main focus of the present study was to evaluate the effects of arginine vasopressin (AVP), previously shown to be increased in the brain during ischemia and to promote edema formation, on activity of the BBB cotransporter. Cerebral microvascular endothelial cell (CMEC) monolayers were cultured in astroglial cell conditioned medium, and Na-K-Cl cotransporter activity was assessed as bumetanide-sensitive (86)Rb influx. In both human and bovine CMECs, as well as in freshly isolated microvessels, AVP stimulated cotransport activity. This stimulatory effect was mimicked by V(1) but not V(2) vasopressin agonists and was blocked by V(1) but not V(2) vasopressin antagonists. Consistent with a V(1) vasopressin receptor mechanism of action, AVP caused an increase in CMEC intracellular [Ca] that was blocked by a V(1) antagonist. Exposing the cells to [Ca]-free media and/or reducing intracellular [Ca] by BAPTA also blocked AVP stimulation of CMEC cotransporter activity, as did the phospholipase C inhibitor U-73122. Finally, we found that while stimulation of CMEC cotransporter activity by AVP occurred within minutes, it was also sustained for hours in the continued presence of AVP. These findings support the hypothesis that AVP, through a V(1) receptor- and [Ca]-dependent mechanism, stimulates the BBB Na-K-Cl cotransporter to participate in ischemia-induced edema formation.

This article reports the results of a cross-sectional data collection in four Russian cities. The objective of the research is to ascertain whether, during the evolution of marketing in a transition to a free market, firms exhibit similar behaviors observed in well-established free-market economies. Structured interviews were conducted with 200 owner/managers of Russian firms. Structural equation modeling was used to test whether environmental turbulence results in a change in marketing orientation, ensuing use of marketing strategies, and improved firm performance. Although the model generally followed Western trends, there were important differences in the effectiveness of pricing and promotional strategies.

This paper analyzes the results of an empirical investigation on attitudes toward consumerism in four developing countries. Comparisons of these consumerism views are made along three different dimensions. Findings provide some support for the “consumerism life cycle pattern.” Alternative reasons for the results are discussed, and directions for research are examined.

Internationalizing the marketing principles course using a foreign study tour is discussed, and the advantages of the foreign study tour over more traditional internationalization methods are addressed. Multiple pedagogical techniques that can be used for an overseas class and variations for applying this concept to other marketing courses are examined.