Mitochondrial energy conversion disturbance with decrease in ATP production as a source of systemic arterial hypertension

This review deals with the cellular mechanisms underlying decreased energy status documented in different tissues from experimental rat models of primary and secondary hypertension as well as the involvement of these abnormalities in the pathogenesis of the disease. Such analyses allow us to hypothesize that dysfunction of mitochondrial energy conversion, caused by distinct stimuli, including generalized disturbances of intracellular Ca2+ handling and mitochondria calcium overload found in primary hypertension, leads to uncoupling of oxidation and phosphorylation and attenuated ATP synthesis. Examples of arterial hypertension accompanied by mitochondrial uncoupling and cell ATP depletion (hyperthyroidism, cold hypertension, cyclosporine A intake, etc.) may be considered as an additional argument supporting this opinion. It means also that despite of differences in triggering mechanisms of mitochondrial dysfunction in all these models, the final outcome, i.e. decreased mitochondrial ATP production, is similar. Attenuated intracellular ATP content, in turn, results in the long-term maintenance of elevated BP by increased sympathetic outflow, whereas augmented ROS production following mitochondrial dysfunction lowers the capacity of the NO-dependent vascular relaxation. In the light of these data the cause of stationary elevated BP in chronic arterial hypertension should be regarded as a compensatory response to decreased mitochondrial ATP synthesis.     

Uroflowmeter, a device for measuring urine volume and urination rate]

The paper deals with the design and construction of a float-type uroflowmeter that is characterized by higher reliability, precision, validity of measurements. The characteristics of the device have been improved by excluding a sliding contact which operates in the corrosive medium, by applying a primary gauge whose output signal is proportional to the instantaneous value of urinary debit.     

Polarographic determination of diuciphon

Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 23, No. 3, pp. 347–349, March, 1989.     

Decreased ATP-synthesis ability of brain mitochondria in spontaneously hypertensive rats

It has been shown previously that a decrease of ATP amount and changed balance of other macroergic phosphates occurs in different tissues of spontaneously hypertensive rats (SHR) compared with control normotensive rats (WKY). AIM: To assess the ability of SHR brain isolated mitochondria to synthesize ATP and to elucidate its relation to extramitochondrial calcium concentration. RESULTS: The present work shows for the first time that SHR brain mitochondria initially differ from WKY ones by decreased (by 30%) ATP synthesis rate. When calcium concentration is increased up to 20 or 40 micromole/l ATP synthesis rates in WKY and SHR mitochondria are about one half compared with the condition when the medium does not contain calcium, but the differences between SHR and WKY remain the same. CONCLUSION: Decreased ATP synthesis rate in SHR mitochondria may be considered as the main cause of cell energy deficiency observed in experimental variant of primary arterial hypertension.     

Estimation of several antidepressants using an amperometric biosensor based on immobilized monoamine oxidase

An amperometric biosensor was developed on the basis of a printed platinum electrode and immobilized monoamine oxidase for detecting antidepressants of various classes. The analytical potential of the electrode was assessed: Petylyl (desipramine) and pyrazidol could be estimated from lower detection limits of 8 × 10⁹ M for Petylyl and 8 × 10⁷ M for pyrazidol. A method for estimating pyrazidol in tablets is described. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 6, pp. 53–56, June, 2007.     

Application of constant-current coulometry for estimation of plasma total antioxidant capacity and its relationship with transition metal contents

Simple and express coulometric method for the evaluation of the total antioxidant capacity (TAC) of human plasma based on the reaction with electrogenerated bromine is applied. TAC of plasma from patients with different ethiology of chronic renal failure was observed. The levels of antioxidant capacity for venous and arterial plasma are authentically different (15+/-1 kCl/L versus 11.7+/-0.7 kCl/L, p<0.01). The application of Vitamin E and ximedon as an antioxidant treatment significantly increase TAC level of plasma. Free liposoluble antioxidants in plasma in alpha-tocopherol units was determined. Redox potential of plasma is measured and its correlation with lg(TAC) is obtained. Transition metal contents of Fe, Cu, Mn, Ni, and Cr in plasma of patients with chronic renal failure is significantly higher than that for a control group. Correlation analysis has shown negative linear regression between TAC value and transition metals concentration in plasma. This confirms interrelation of processes with participation of free radicals, antioxidants and transition metals as donors of electrons in chain radical processes. Moreover, it shows utility of common parameters, TAC for example, for estimation of efficiency of antioxidant defense system in living organism, in particular its antioxidant status.     

Decreased ATP-synthesis ability of liver mitochondria in spontaneously hypertensive rats (SHR): role of calcium overload of the mitochondria

It has been shown previously, that a decrease of ATP amount and changed balance of the other macroergic phosphates are observed in different tissues of spontaneously hypertensive rats (SHR) compared with the normotensive controls (WKY). The aim of the present study was to assess the ability of SHR liver isolated mitochondria to synthesize ATP and to clarify its dependence on extramitochondrial calcium concentration. Macroergic phosphate concentrations were measured by high performance liquid chromatography (HPLC). The present work shows for the first time, that SHR liver mitochondria initially differ from WKY ones by decreased (by 30%) ATP synthesis rate. Respiratory control coefficient and phosphorylation rate in SHR and WKY mitochondria change in different manner when extramitochondrial calcium concentration increases from 0 to 50 microM. When calcium concentration is increased up to 50 microM both parameters in WKY mitochondria are about one half compared with the condition when the medium does not contain calcium. In the conditions, when the medium contains 50 microM of calcium, complete uncoupling of oxidation and phosphorylation in SHR mitochondria is observed. Thus the decrease of ATP synthesis rate in SHR mitochondria in conjunction with reduced tolerance to calcium overload (by respiratory control coefficient and phosphorylation rate) in comparison with WKY may be considered as the main cause of cell energy deficiency, observed in experimental variant of primary arterial hypertension.