Sex differences in adaptive downregulation of pre-macula densa sodium transporters with ANG II infusion in mice.

An increase in blood pressure (BP) due to angiotensin II (ANG II) infusion or other means is associated with adaptive pressure natriuresis due to reduced sodium reabsorption primarily in proximal tubule (PT) and thick ascending limb (TAL). We tested the hypothesis that male and female mice would show differential response to ANG II infusion with regard to the regulation of the protein abundance of sodium transporters in the PT and TAL and that these responses would be modulated by aging. Young (approximately 3 mo) and old (approximately 21 mo) male and female mice were infused with ANG II at 800 ng x kg body wt(-1) x min(-1) by osmotic minipump for 7 days or received a sham operation.

Sex and age result in differential regulation of the renal thiazide-sensitive NaCl cotransporter and the epithelial sodium channel in angiotensin II-infused mice.

Background/aims: We determined the effects of age and sex on the blood pressure (BP) response to angiotensin II (Ang II) infusion and evaluated the potential mechanistic role of the thiazide-sensitive NaCl cotransporter (NCC) and the epithelial sodium channel (ENaC).

Methods: Male and female mice (approximately 3 or 21 months of age) were infused with Ang II or control for 7 days.

Results: Males had a greater BP response to Ang II, somewhat enhanced by aging.

Chronic candesartan alters expression and activity of NKCC2, NCC, and ENaC in the obese Zucker rat.

The obese Zucker rat reportedly has increased activity of the intrarenal renin-angiotensin-aldosterone system, which conceptually could contribute to elevated salt sensitivity and blood pressure (BP). Our aim was to determine whether there was increased angiotensin II type 1 receptor (AT(1)R)-mediated upregulation of expression or activity of the bumetanide-sensitive Na-K-2Cl cotransporter, the thiazide-sensitive Na-Cl cotransporter (NCC), and/or the epithelial sodium channel (ENaC) in obese vs. lean Zucker rats.

Sex differences in renal nitric oxide synthase, NAD(P)H oxidase, and blood pressure in obese Zucker rats.

Background: By increasing renal oxidative stress, obesity may alter the protective effect of female sex on blood pressure (BP).

Objectives: The aim of this study was to determine whether female rats had altered expression and activity of renal nicotinamide adenine dinucleotide (phosphate) [NAD(P)H] oxidase and nitric oxide synthase (NOS), enzymes important in superoxide and nitric oxide generation, respectively, and whether this relationship was altered in obesity.

Methods: Male and female, lean and obese Zucker rats were fed progressively higher levels of NaCl over 54 days while BP was measured by radiotelemetry.

Sex and body-type interactions in the regulation of renal sodium transporter levels, urinary excretion, and activity in lean and obese Zucker rats.

Background: Female humans and rodents are relatively protected against the development of hypertension and renal disease. Whether this protection is modified during insulin resistance and obesity, however, is not known.

Objective: Because renal sodium reabsorption has a central role in determining blood pressure, we hypothesized that lean female rats would bave reduced renal expression, activity, and urinary excretion of 8 major sodium transporters/channels.

Trafficking of ENaC subunits in response to acute insulin in mouse kidney.

Studies done in cell culture have demonstrated that insulin activates the epithelial sodium channel (ENaC) via a variety of mechanisms. However, to date, upregulation of ENaC in native renal tissue by in vivo administration of insulin has not been demonstrated. To address this, we injected 6-mo-old male C57BL/CBA mice (n = 14/group) intraperitoneally with vehicle or 0.