Hypoxia increases BK channel activity in the inner mitochondrial membrane.

To explore the potential function of the BK channel in the inner mitochondrial membrane under physiological and hypoxic conditions, we used on-mitoplast and whole-mitoplast patches. Single BK channels had a conductance of 276+/-9 pS under symmetrical K(+) solutions, were Ca(2+)- and voltage-dependent and were inhibited by 0.1 microM charybdotoxin.

Chronic high-inspired CO2 decreases excitability of mouse hippocampal neurons.

To examine the effect of chronically elevated CO(2) on excitability and function of neurons, we exposed mice to 8 and 12% CO(2) for 4 wk (starting at 2 days of age), and examined the properties of freshly dissociated hippocampal neurons obtained from slices. Chronic CO(2)-treated neurons (CC) had a similar input resistance (R(m)) and resting membrane potential (V(m)) as control (CON). Although treatment with 8% CO(2) did not change the rheobase (64 +/- 11 pA, n = 9 vs.

Antiapoptotic mechanism of insulin in reoxygenation-induced injury in cultured cardiomyocytes of neonatal rats.

To examine the protective effect of insulin on reoxygenation-induced injury and explore the underlying mechanisms, the model of anoxia/reoxygenation (A/R) injury was established by inducing anoxia for 2 h and reoxygenation for 4 h in cultured cardiomyocytes of neonatal rats. The rats were randomized to four groups receiving vehicle, insulin, LY294002, insulin plus LY294002 at the onset of reoxygenation after 2 h of anoxia. At the end of reoxygenation of 4 h, activity of lactate dehydrogenase (LDH) and content of malondialdehyde (MDA) were spectrophotometrically determined, apoptosis of cardiomyocytes were detected by using TUNEL and DNA Ladder, and Western blotting was employed to examine the expression of phosphorylated Akt in all groups.

Role of norepinephrine in development of short-term myocardial hibernation.

Aim: To investigate the role of norepinephrine in the development of short-term myocardial hibernation.

Methods: Hearts were removed from rats and set up as isometrically beating or short-term hibernation models. The hearts were perfused with modified Krebs-Henseleit buffer under a controlled perfusion pressure.

Folic acid reduces adhesion molecules VCAM-1 expession in aortic of rats with hyperhomocysteinemia.

To investigate effects of supplementation of folic acid on the expression of adhesion molecules VCAM-1 in the aortas of rats with hyperhomocysteinemia. Thirty male SD rats (200 +/- 20 g) were invided into 3 groups (n = 10 for each group): control group(Control), high Met group(Met) and Met plus Folate group(Met + Folate), fed. for 45 days.

[Association between polymorphism of CYP17 gene and serum hormone concentrations in aged men].

Objective: To investigate the association between polymorphism of CYP17 gene and serum hormone concentrations in aged men.

Methods: Eighty-three healthy men at the average age of 66.7 were divided into a < 66.

Effect of chronically elevated CO2 on CA1 neuronal excitability.

To study the effect of chronically elevated CO(2) on the excitability and function of neurons, we exposed mice to 7.5-8% CO(2) for approximately 2 wk (starting at 2 days of age) and examined the properties of freshly dissociated hippocampal neurons. Neurons from control mice (CON) and from mice exposed to chronically elevated CO(2) had similar resting membrane potentials and input resistances.

Calcium influx via L- and N-type calcium channels activates a transient large-conductance Ca2+-activated K+ current in mouse neocortical pyramidal neurons.

Ca2+-activated K+ currents and their Ca2+ sources through high-threshold voltage-activated Ca2+ channels were studied using whole-cell patch-clamp recordings from freshly dissociated mouse neocortical pyramidal neurons. In the presence of 4-aminopyridine, depolarizing pulses evoked transient outward currents and several components of sustained currents in a subgroup of cells. The fast transient current and a component of the sustained currents were Ca2+ dependent and sensitive to charybdotoxin and iberiotoxin but not to apamin, suggesting that they were mediated by large-conductance Ca2+-activated K+ (BK) channels.

Maturation of neuronal excitability in hippocampal neurons of mice chronically exposed to cyclic hypoxia.

To examine the effects of chronic cyclic hypoxia on neuronal excitability and function in mice, we exposed mice to cyclic hypoxia for 8 h daily (9 cycles/h) for approximately 2 wk (starting at 2-3 days of age) and examined the properties of freshly dissociated hippocampal neurons obtained from slices. Compared with control (Con) hippocampal CA1 neurons, exposed neurons (CYC) had similar resting membrane potentials (V(m)) and action potentials (AP). CYC neurons, however, had a lower rheobase than Con neurons.

Na+ channel expression and neuronal function in the Na+/H+ exchanger 1 null mutant mouse.

Mice lacking Na(+)/H(+) exchanger 1 (NHE1) suffer from recurrent seizures and die early postnatally. Although the mechanisms for seizures are not well established, our previous electrophysiological work has shown that neuronal excitability and Na(+) current density are increased in hippocampal CA1 neurons of these mutant mice. However, it is unknown whether this increased density is related to altered expression or functional regulation of Na(+) channels.

Identification of an additional hypoxia responsive element in the glyceraldehyde-3-phosphate dehydrogenase gene promoter.

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a multifunctional enzyme overexpressed in many tumors and induced by hypoxia in normal and malignant cells. The degree to which hypoxia transcriptionally activates GAPDH is cell type specific. The GAPDH promoter region contains a hypoxia responsive element (HRE) consisting of a hypoxia inducible factor-1 (HIF-1) consensus binding site plus adjacent sequence [Graven et al.

[Measurement of fracture malrotation after interlocking intramedullary nailing of femoral shaft fracture].

Objective: To study the quantitative measurement of the extent of malrotation after interlocking intramedullary nailing of femoral shaft fracture.

Method: CT scan ("routine method") applied in 36 femoral shaft fractures that had been treated with close reduction and interlocking intramedullary nailing. For the judgement of the extent of malrotation, the anteversion of both fracture side and contralateral side were measured and the difference between the 2 sides was evaluated.