Aging skin is functionally anaerobic: importance of coenzyme Q10 for anti aging skin care

The functional loss of mitochondria represents an inherent part in modern theories trying to explain the cutaneous aging process. The present study shows significant age-dependent differences in mitochondrial function of keratinocytes isolated from skin biopsies of young and old donors. Our data let us postulate that energy metabolism shifts to a predominantly non-mitochondrial pathway and is therefore functionally anaerobic with advancing age. CoQ10 positively influences the age-affected cellular metabolism and enables to combat signs of aging starting at the cellular level. As a consequence topical application of CoQ10 is beneficial for human skin as it rapidly improves mitochondrial function in skin in vivo.

Regulation of calcium sparks and spontaneous transient outward currents by RyR3 in arterial vascular smooth muscle cells

Intracellular Ca(2+) levels control both contraction and relaxation in vascular smooth muscle cells (VSMCs). Ca(2+)-dependent relaxation is mediated by discretely localized Ca(2+) release events through ryanodine receptor (RyR) channels in the sarcoplasmic reticulum (SR). These local increases in Ca(2+) concentration, termed sparks, stimulate nearby Ca(2+)-activated K(+) (BK) channels causing BK currents (spontaneous transient outward currents or STOCs). STOCs are hyperpolarizing currents that oppose vasoconstriction. Several RyR isoforms are coexpressed in VSMCs; however, their role in Ca(2+) spark generation is unknown. To provide molecular information on RyR cluster function and assembly, we examined Ca(2+) sparks and STOCs in RyR3-deficient freshly isolated myocytes of resistance-sized cerebral arteries from knockout mice and compared them to Ca(2+) sparks in cells from wild-type mice. We used RT-PCR to identify RyR1, RyR2, and RyR3 mRNA in cerebral arteries. Ca(2+) sparks in RyR3-deficient cells were similar in peak amplitude (measured as F/F(0)), width at half-maximal amplitude, and duration compared with wild-type cell Ca(2+) sparks. However, the frequency of STOCs (between -60 mV and -20 mV) was significantly higher in RyR3-deficient cells than in wild-type cells. Ca(2+) sparks and STOCs in both RyR3-deficient and wild-type cells were inhibited by ryanodine (10 micromol/L), external Ca(2+) removal, and depletion of SR Ca(2+) stores by caffeine (1 mmol/L). Isolated, pressurized cerebral arteries of RyR3-deficient mice developed reduced myogenic tone. Our results suggest that RyR3 is part of the SR Ca(2+) spark release unit and plays a specific molecular role in the regulation of STOCs frequency in mouse cerebral artery VSMCs after decreased arterial tone.

Mice with disrupted BK channel beta1 subunit gene feature abnormal Ca(2+) spark/STOC coupling and elevated blood pressure

Large-conductance potassium (BK) channels in vascular smooth muscle cells (VSMCs) sense both changes in membrane potential and in intracellular Ca(2+) concentration. BK channels may serve as negative feedback regulators of vascular tone by linking membrane depolarization and local increases in intracellular Ca(2+) concentration (Ca(2+) sparks) to repolarizing spontaneous transient outward K(+) currents (STOCs). BK channels are composed of channel-forming BKalpha and auxiliary BKbeta1 subunits, which confer to BK channels an increased sensitivity for changes in membrane potential and Ca(2+). To assess the in vivo functions of this ss subunit, mice with a disrupted BKbeta1 gene were generated. Cerebral artery VSMCs from BKbeta1 -/- mice generated Ca(2+) sparks of normal amplitude and frequency, but STOC frequencies were largely reduced at physiological membrane potentials. Our results indicate that BKbeta1 -/- mice have an abnormal Ca(2+) spark/STOC coupling that is shifted to more depolarized potentials. Thoracic aortic rings from BKbeta1 -/- mice responded to agonist and elevated KCl with a increased contractility. BKbeta1 -/- mice had higher systemic blood pressure than BKbeta1 +/+ mice but responded normally to alpha(1)-adrenergic vasoconstriction and nitric oxide-mediated vasodilation. We propose that the elevated blood pressure in BKbeta1 -/- mice serves to normalize Ca(2+) spark/STOC coupling for regulating myogenic tone. The full text of this article is available at http://www.circresaha.org.

Ignition of calcium sparks in arterial and cardiac muscle through caveolae

Ca(2+) sparks are localized intracellular Ca(2+) events released through ryanodine receptors (RyRs) that control excitation-contraction coupling in heart and smooth muscle. Ca(2+) spark triggering depends on precise delivery of Ca(2+) ions through dihydropyridine (DHP)-sensitive Ca(2+) channels to RyRs of the sarcoplasmic reticulum (SR), a process requiring a very precise alignment of surface and SR membranes containing Ca(2+) influx channels and RyRs. Because caveolae contain DHP-sensitive Ca(2+) channels and may colocalize with SR, we tested the hypothesis that caveolae are the structural element necessary for the generation of Ca(2+) sparks. Using methyl-ss-cyclodextrin (dextrin) to deplete caveolae, we found that dextrin dose-dependently decreased the frequency, amplitude, and spatial size of Ca(2+) sparks in arterial smooth muscle cells and neonatal cardiomyocytes. However, temporal characteristics of Ca(2+) sparks were not significantly affected. We ruled out the possibility that the decreases in Ca(2+) spark frequency and size are caused by changes in DHP-sensitive L-type channels, SR Ca(2+) load, or changes in membrane potential. Our results suggest a novel signaling model that explains the formation of Ca(2+) sparks in a caveolae microdomain. The transient elevation in [Ca(2+)](i) at the inner mouth of a single caveolemmal Ca(2+) channel induces simultaneous activation and thus opens several RyRs to generate a local Ca(2+) release event, a Ca(2+) spark. Alterations in the molecular assembly and ultrastructure of caveolae may lead to pathophysiological changes in Ca(2+) signaling. Thus, caveolae may be intimately involved in cardiovascular cell dysfunction and disease.

Calcium sparks in human coronary artery smooth muscle cells resolved by confocal imaging

OBJECTIVE

The observation of local 'elementary' Ca2+ release events (Ca2+ sparks) through ryanodine receptor (RyR) channels in the sarcoplasmic reticulum (SR) has changed our understanding of excitation-contraction (EC) coupling in cardiac and smooth muscle. In arterial smooth muscle, Ca2+ sparks have been suggested to oppose myogenic vasoconstriction and to influence vasorelaxation by activating co-localized Ca2+ activated K+ (K(Ca)) channels (STOCs). However, all prior studies on Ca2+ sparks have been performed in non-human tissues.

METHODS

In order to understand the possible significance of Ca2+ sparks to human cardiovascular function, we used high spatial resolution confocal imaging to record Ca2+ sparks in freshly-isolated, individual myocytes of human coronary arteries loaded with the Ca2+ indicator fluo-3.

RESULTS

Local SR Ca2+ release events recorded in human myocytes were similar to 'Ca2- sparks' recorded previously from non-human smooth muscle cells. In human myocytes, the peak [Ca2+]i amplitudes of Ca2+ sparks (measured as F/F0) and width at half-maximal amplitude were 2.3 and 2.27 microm, respectively. The duration of Ca2+ sparks was 62 ms. Ca2+ sparks were completely inhibited by ryanodine (10 micromol/l). Ryanodine-sensitive STOCs could be identified with typical properties of K(Ca) channels activated by Ca2+ sparks.

CONCLUSION

Our data implies that modern concepts suggesting an essential role of Ca2+ spark generation in EC coupling recently derived from non-human muscle are applicable to human cardiovascular tissue. Although the basic properties of Ca2+ sparks are similar, our results demonstrate that Ca2+ sparks in coronary arteries in humans, have features distinct from non-arterial smooth muscle cells of other species.

Ca2+ channels, Ca2+ sparks, and regulation of arterial smooth muscle function

In cardiac, skeletal, and arterial muscle, transient, spatially localized elevations in [Ca2+]i, termed "Ca2+ sparks", have been observed using confocal laser scanning microscopy. Ca2+ sparks are thought to represent "elementary" Ca2+ release events, which arise from one or more ryanodine receptor (RyR) channels in the sarcoplasmic reticulum (SR). In striated muscle, Ca2+ sparks are thought to be key elements of excitation-contraction coupling. In arterial smooth muscle, Ca2+ sparks have been suggested to oppose myogenic vasoconstriction and to influence vasorelaxation. Using a developmental model, we have investigated whether RyRs causing Ca2+ sparks and activation of Ca(2+)-activated K+ (KCa) channels (STOCs) function as "elementary" Ca2+ release units that regulate arterial myogenic tone. Whereas increases in the global [Ca2+]i induce sustained constriction of arterial smooth muscle, Ca2+ sparks induce vasodilation through the local activation of KCa channels. In cerebral arteries, the global bulk [Ca2+]i and a Ca2+ spark frequency < 10(-2) Hz/cell do not cause sufficient KCa channel activity to regulate membrane potential of smooth muscle cells and myogenic tone. The frequency of Ca2+ sparks and STOCs is regulated by agents that modulate protein kinase G and protein kinase A activity. Our findings suggest that "elementary" Ca2+ release units may represent novel, important therapeutic targets for regulating function of the intact arterial smooth muscle tissue.

[Therapeutic aspects of endoscopic polypectomy]

466 endoscopic polypectomies of the upper and lower gastrointestinal tract were analysed according to their curative value. In 254 removed polyps of the upper gastrointestinal tract the result of the histological examination was twice a proof of a carcinoma. One it had to be after-resected, once a carcinoid, five times bleeding polyps were removed. Four times prolapsing gastric polyps were removed in the bulbus duodeni. In these cases intermittent disturbances of the passage could be repaired. Thus the endoscopic polypectomy in the upper gastrointestinal tract was of therapeutic value in 4.3%. In the lower intestinal tract in 204 polypectomies 16 focal carcinomas or invasive carcinomas removed in the healthy tissue, 1 carcinoid and 98 bleeding adenomas were cut away. Thus the coloscopic polypectomy was connected with a therapeutic use in 56.3%. 81.8% of the polyps was tubular, papillary or villous adenomas. Taking into consideration the "adenoma-cancer-sequence", the coloscopic polypectomy must thus be regarded as a prophylactic and curative method, while in the polypectomy in the upper gastrointestinal tract the diagnostic value is in the first place.

[The value of fiber gastroscopy and targeted gastrobiopsy in the diagnosis of stomach ulcers and tumors]

In 2,000 patients the fiber-gastroscopic and bioptic findings were tested with the help of control examinations, results of operations and course observations. Here the fibergastroscopic diagnosis tumour was confirmed in 89.4%. 13 times a wrong diagnosis of tumour was made. Here different substrates were in question (ventricular ulcers, polypous hyperblastic mucous membrane and others). 11 carcinomas were gastroscopically not recognized as tumour. In 25 cases (20%) of the histological investigation of bioptically taken tissue did not result in a confirmation of the fiber-gastroscopic diagnosis of tumour. But 19 times of them the histology was falsely negative. The supplementation of the gastroscopy by biopsy resulted in a right diagnosis in 93.6%. By control examinations a further increase of the accuracy to 96.8% could be reached.

[Ulcer anamnesis and gastroduodenoscopic findings--a contribution to the symptomatology of gastroduodenal ulcers]

513 patients who were gastroduodenoscopically examined on account of suspicion of ulcer were aimedly inquired for 18 typical ulcer complaints. Compared with patients with normal gastroduodenoscopic findings patients peptic ulcers of erosions of the gastric mucous membrane had significantly more frequently symptoms of the gastrointestinal haemorrhage, patients with ulcus ventriculi had, moreover, inappetence and vomiting, patients with duodenal ulcer a late pain in the centre of the epigastrium and in the right epigastrium. But these symptoms did not allow a significant differentiation between the patients with ventricular ulcer and duodenal ulcer. Patients without pathological gastroduodenoscopic findings had significantly more frequently an incompatibility of food and connected with this sensation of fullness. A typical symptomatology of ulcer may, indeed, be present in the individual case, but according to the results of the study it is no sufficient proof for the actual existence of a peptic ulcer and is thus of little differential-diagnostic value.

[Fiber-optic endoscopy demonstration, incidence and clinical significance of intestinal lymphangiectasis]

The intestinal lymphangiectasia can be proved enteroscopically, laparoscopically as well as histologically after preceding aimed or unaimed biopsy. In 2,250 fibre-endoscopic examinations of the upper gastrointestinal tract we found 54 times endoscopically and 48 times also histologically a lymphangiectasia. Of these 54 patients 9 had an advanced carcinoma of the stomach. The evoking causes of the lymphangiectasia are discussed. When an intestinal lymphagniectasia is diagnosed it should always be sought for an evoking cause and last not least should be thought of a primary or secondary neoformation in the region of the epigastrium.

[Endoscopic demonstration of heterotopic gastric mucosa in the duodenum]

On the basis of 8 observations in 3,140 duodenoscopies is referred to the endoscopic picture of heterotopies of the gastric mucous membrane. The heterotopic mucous membrane of the stomach was found in polypoid rice-grain-sized to pea-sized lesions of the duodenum. The histological examination four times resulted in a mucous membrane of the stomach of corpus type, three times of antrum type and once only in foveolar epithelium. As to other findings endoscopically were twice observed erosions of the gastric mucous membrane or of the mucous membrane of the bulb, respectively, once an antrum polypus, in no case ulcers. Once an achlorhydria was present. A hyperchlorhydria was to be proved in no case. The clinical significance of the heterotopia of the gastric mucous membrane in the duodenum as well as the cause of its existence are discussed.

[Humoral immune reaction in chronic liver diseases]

In 60 patients with a morphologically ascertained chronic liver disease and 40 hepatologically examined patients with a healthy liver of a control group the quantitative determination of the immunoglobulin and the immunofluorescence-serological determination of antibodies against nuclei, smooth musculature and mitochondria were carried out. Only in one female patient with a chronic active hepatitis out of 51 patients with morphologically ascertained liver cirrhosis or chronic active hepatitis antibodies against nuclei and smooth musculature in a level of the titre of more than 1 : 40 and only in 2 female patients with a primary biliary cirrhosis antibodies against mitochondria could be proved in a level of the titre of more than 160. Titres of antibodies lying below were found in the group of patients with liver diseases and the control group in the same frequency, so that an autoimmune form of the cryptogenic cirrhosis could not be differentiated. The proof of antibodies against nuclei and smooth musculature of a high titre in connection with an isolated increase of the IgG is of special diagnostic importance for the autoimmune form of the chronic active hepatitis; the same is the case in the proof of antibodies against mitochondria of a high titre in connection with an isolated increase of IgM.