John P. Hayslett

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The purpose of this study was to determine whether there is a correlation between phosphorylation and activity of the epithelial sodium channel (ENaC). The three subunits that form the channel were immunoprecipitated from A6 cells by using specific polyclonal antibodies after labeling cells with (35)S or (32)P. When immune complexes were resolved on(More)
There are conflicting reports in the literature regarding the adenosine receptor that mediates the increase in sodium transport in the A6 cell. In this study we used specific A1 and A2 adenosine receptor agonists and antagonists, as well as two different subclones of the A6 cell, to determine which adenosine receptor mediates the increase in sodium(More)
Vasopressin is known to activate two types of cell surface receptors; V2, coupled to adenylate cyclase, and V1, linked to a Ca(2+)-dependent transduction system. We investigated whether arginine vasopressin (AVP) stimulation of electrogenic sodium transport in A6 cells, derived from Xenopus laevis, is mediated by activation of either one or both types of(More)
Studies were performed to 1) systematically compare Ling-Gerard microelectrodes and electrodes with large tips (3 to 5 mu O.D.) in the measurement of the transepithelial potential difference (PD) in the mammalian distal tubule and 2) to examine the sign and magnitude of the transepithelial PD along the length of the distal tubule. Recordings made with the(More)
To examine the role of intrarenal hemodynamics in in obstructive nephropathy, we determined cortical blood flow distribution (CBFD) in rats with bilateral ureteral occlusion (BUO) and unilateral ureteral occlusion (UUO) during and after release of obstruction. Prior to release of obstruction of 24 hours' duration, we found that outer cortical perfusion(More)
Studies were performed on monolayers of cultured A6 cells, grown on permeable filters, to determine the second messenger system involved in the aldosterone-induced increase in electro-genic sodium transport. Addition of aldosterone (1 p&M) to the solution bathing the basal surface of cells caused both an increase in Isc and threefold transient rise in(More)
Although acute renal failure, caused either by renal ischemia or nephrotoxic agents, is usually characterized by oliguria, a severe fall in glomerular filtration rate, and a fall in renal blood flow, some patients and experimental models display a non-oliguric pattern of renal injury. The present study was designed to evaluate the mechanism of preservation(More)
Repeat DC countershock reproducibly results in myocardial necrosis in dogs. In this model, myocardial technetium-99m pyrophosphate (PYP) uptake correlates linearly with tissue creatine kinase depletion (r = -0.83). The effect of pretreatment with methylprednisolone (MP) was studied with PYP in 25 dogs. In myocardium damaged by countershock, 12 MP dogs had(More)
The excised patch clamp configuration provides a unique technique for some types of single channel analyses, but maintenance of stable, long-lasting preparations may be confounded by rundown and/or rapid loss of seal. Studies were performed on the amiloride-sensitive Na+ channel, located on the apical surface of A6 cells, to determine whether the(More)
This paper is the first in a new Clinical Feature Series that will be a regular feature in future issues of The Yale Journal of Biology and Medicine. Papers in the series will focus on cases and disease processes of general interest to the practicing clinician, with the goal being to present the perspectives of expert clinicians regarding the accurate(More)