Alkalosis increases muscle K+ release, but lowers plasma [K+] and delays fatigue during dynamic forearm exercise.

Alkalosis enhances human exercise performance, and reduces K+ loss in contracting rat muscle. We investigated alkalosis effects on K+ regulation, ionic regulation and fatigue during intense exercise in nine untrained volunteers. Concentric finger flexions were conducted at 75% peak work rate (3 W) until fatigue, under alkalosis (Alk, NaHCO3, 0.

Lectin chromatography of extrarenal renin protein in human plasma and tissues: potential endocrine function via the renin receptor.

Secretion of prorenin from extrarenal tissues comprises approximately half of the renin protein in plasma; its origin is unknown. The discovery of a prorenin/renin receptor that activates vascular tissue kinases raises interest in this otherwise inactive component. We have studied its glycosylation as this may distinguish it from renal renin.

Hypertension in the (mRen-2)27 rat is not explained by enhanced kinetics of transgenic Ren-2 renin.

Enhanced efficiency of the reaction between transgenic Ren-2 mouse renin and endogenous rat angiotensinogen has been suggested as 1 mechanism that contributes to the accelerated hypertension and increased tissue angiotensin of the (mRen-2)27 transgenic rat. This was tested in a study conducted at pH 7.4 in vitro that compared the kinetic constants of purified mouse Ren-2 and rat renin (each at 100, 75, 50, and 25 pmol/L) reacting with physiologic concentrations of rat angiotensinogen (0 to 4 micromol/L).

The renin-angiotensin system influences ocular endothelial cell proliferation in diabetes: transgenic and interventional studies.

Neovascularization in the retina and iris of diabetic patients is a major cause of severe visual loss. However, study of these lesions is compromised by the lack of a comparable diabetic rodent model. Because the vasoactive and angiogenic agent, angiotensin II, is involved in diabetic microvascular disease, we aimed to determine whether endothelial cell proliferation could be induced in the retinae and irides of hypertensive transgenic (mRen-2)27 rats that display an enhanced extra-renal renin-angiotensin system (RAS), including the eye.

Impaired K+ regulation contributes to exercise limitation in end-stage renal failure.

Background: Patients with end-stage renal failure (ESRF) exhibit grossly impaired maximal exercise performance. This study investigated whether K+ regulation during exercise is impaired in ESRF and whether this is related to reduced exercise performance.

Methods: Nine stable hemodialysis patients and eight controls (CON) performed incremental cycling exercise to volitional fatigue, with measurement of peak oxygen consumption (VO2 peak).

Characterisation of a thymic renin-angiotensin system in the transgenic m(Ren-2)27 rat.

We previously showed the rat thymus contains and secretes active renin. However, the cellular location of the thymic renin-angiotensin system (RAS) is unknown. To more easily study the thymic RAS we used the hypertensive transgenic (mRen-2)27 rat which overexpresses renin and angiotensin in extra-renal tissues.

Effects of low-dose and early versus late perindopril treatment on the progression of severe diabetic nephropathy in (mREN-2)27 rats.

It was previously reported that transgenic (mRen-2)27 rats with streptozotocin-induced diabetes mellitus progressively develop advanced nephropathy in 12 wk. These lesions are largely prevented when the angiotensin-converting enzyme inhibitor perindopril is administered from the time of induction of diabetes mellitus. This study aimed to determine the lowest dose of early perindopril treatment required for substantial improvement of renal function and structure and to investigate whether late intervention prevents or reverses the progression of established renal lesions.