Biomedical subjects

A Schmidt

Publications and source records attributed to A Schmidt.

At least 55 records · Page 3Linked to original sources

PubMed2004

Influence of cold ischemia time on complement activation, neopterin, and cytokine release in liver transplantation.

OBJECTIVES: The aim of this study was to determine whether a cold ischemia time (CIT) of >12 hours influences the activation of complement as well as the plasma concentrations of neopterin, interleukin (IL)-6, or IL-8 in orthotopic liver transplantation (OLT). PATIENTS AND METHODS: Eighteen consecutive patients undergoing OLT using a veno-venous bypass technique were divided into 2 groups: duration of CIT >12 hours (group 1; n = 11), and CIT <12 hours (group 2; n = 7). Blood samples were drawn preoperatively, 1 minute before, and 120 minutes after reperfusion. RESULTS: Preoperatively, complement split products, neopterin, IL-6, and IL-8 levels did not differ between the groups. At 120 minutes after reperfusion, the concentrations of C3a, SC5b-9, neopterin, IL-6, and IL-8 were significantly increased in both groups compared with the preoperative values or the levels determined 1 minute before reperfusion (P < .05). Patients in group 1 showed significantly higher IL-8 levels at 120 minutes after reperfusion (P < .05). CONCLUSION: Complement is activated and pro-inflammatory cytokines released after reperfusion in OLT using a veno-venous bypass technique, but only IL-8 plasma levels were influenced by the duration of CIT. Therefore, alterations following prolonged CIT seem to not be complement-mediated.

Cold Temperature↗

PubMed2004

Acute exercise has no effect on ghrelin plasma concentrations.

Exercise is a potent, dose-dependent stimulus of growth hormone (GH) secretion. The hypothalamic peptides, GH-releasing hormone (GHRH) and somatostatin are regarded as major regulators of this stimulation. The role of the stomach-derived peptide ghrelin, which has been shown to exert strong GH releasing effects, has not been fully characterized yet. We therefore studied GH and ghrelin plasma concentrations in response to graded levels of exercise in eight healthy young volunteers. After determination of their individual maximal exercise capacity, all individuals underwent a treadmill exercise at 50 %, 70 %, and 90 % of maximum oxygen consumption (VO (2)max) on different days. Maximal GH response to exercise was observed after 40 minutes at 50 % VO (2)max and after 20 minutes at 70 and 90 % VO (2max). GH serum concentrations increased significantly at all three exercise intensities (GH peak concentrations were 5.8 +/- 2.3 ng/ml, 12.0 +/- 3.2 ng/ml, and 9.8 +/- 4.7 ng/ml, respectively). In contrast, ghrelin plasma concentrations remained unchanged at all three workloads. Assuming that the sensitivity of the GH neuroendocrine/metabolic regulation of GH is unaltered, ghrelin does not participate in the regulation of the GH response to exercise in healthy males.

Adult↗

PubMed2004

The effect of garlic on arteriosclerotic nanoplaque formation and size.

OBJECTIVE: In an in vitro biosensor model (PCT/EP 97/05212), the interplay between different lipoproteins in arteriosclerotic nanoplaque formation, as well as aqueous garlic extract (0.2-5.0 g/l from LI 111 powder) as a possible candidate drug against arterio/atherosclerosis were tested within the frame of a high throughput screening. METHODS: The processes described below were studied by ellipsometric techniques quantifying the adsorbed amount (nanoplaque formation) and layer thickness (nanoplaque size). A thorough description of the experimental setup has been given previously. RESULTS: Proteoheparan sulfate (HS-PG) adsorption to hydrophobic silica was monoexponential and after approximately 30 min constant. The addition of 2.52 mmol/l Ca2+ led to a further increase in HS-PG adsorption because Ca2+ was bound to the polyanionic glycosaminoglycan (GAG) chains thus screening their negative fixed charges and turning the whole molecule more hydrophobic. Incubation with 0.2 g/l aqueous garlic extract (GE) for 30 min did not change the adsorption of HS-PG. However, the following addition of Ca2+ ions reduced the increase in adsorption by 50.8% within 40 min. The adsorption of a second Ca2+ step to 10.08 mmol/l was reduced by even 82.1% within the next 40 min. Having detected this inhibition of receptor calcification, it could be expected that the build-up of the ternary nanoplaque complex is also affected by garlic. The LDL plasma fraction (100 mg/dl) from a healthy probationer showed beginning arteriosclerotic nanoplaque formation already at a normal blood Ca2+ concentration, with a strong increase at higher Ca2+ concentrations. GE, preferably in a concentration of 1 g/l, applied acutely in the experiment, markedly slowed down this process of ternary aggregational nanoplaque complexation at all Ca2+ concentrations used. In a normal blood Ca2+ concentration of 2.52 mmol/l, the garlic induced reduction of nanoplaque formation and molecular size amounted to 14.8% and 3.9%, respectively, as compared to the controls. Furthermore, after ternary complex build-up, GE similar to HDL, was able to reduce nanoplaque formation and size. The incubation time for HDL and garlic was only 30 min each in these experiments. Nevertheless, after this short time the deposition of the ternary complex decreased by 6.2% resp. 16.5%, i.e. the complex aggregates were basically resolvable. CONCLUSIONS: These experiments clearly proved that garlic extract strongly inhibits Ca2+ binding to HS-PG. In consequence, the formation of the ternary HS-PG/LDL/Ca2+ complex, initially responsible for the 'nanoplaque' composition and ultimately for the arteriosclerotic plaque generation, is decisively blunted.

Arteriosclerosis↗

PubMed2004

Role of p53 mutations, protein function and DNA damage for the radiosensitivity of human tumour cells.

PURPOSE: The tumour suppressor protein p53 is considered to have an impact on the radiosensitivity of tumour cells. However, this concept does not easily translate to the tumour sensitivity in the clinics. The aim of the present study was to determine whether a functional or dysfunctional p53 is associated with a sensitive or resistant phenotype. It was further studied whether DNA damage might be an additive factor by which p53 has impact on cell survival. MATERIALS AND METHODS: Nine human tumour cell lines were studied for p53 mutation by direct sequencing of exons 4-9. Regulation of p53 and p21(cip1/waf1) protein was assessed by immunoblotting and cell cycle effects by combining 5-bromodeoxyuridine incorporation and flow cytometry. RESULTS AND CONCLUSION: Three strains (RT112, Du145, SCC4451) were found to have a missense-mutation in the core domain and one did not express p53 at all (HeLa), presumably due to HPV18 infection. Immunoblots of these cells showed neither a regulated p53 nor p21 expression. The cells did not arrest in G1 phase after X-irradiation but did arrest in G2/M. All cells expressing wild-type protein (LNCaP, T47D-B8, MCF-7 and sublines BB and Bus) showed an intact p53 and p21 regulation and a modest arrest in both G1 and G2/M. Thus, in contrast to other studies, all tumour cells investigated showed either a typical p53wt or mutant (mut) pattern. Protein function was compared with cell survival and DNA damage, as assessed previously. p53 wild-type cells were on average 1.3-times (n.s.) more radiosensitive than mutant cells, but there was a considerable overlap between both groups. Further, the 1.3-fold enhanced resistance of cells lacking wild-type p53 was paralleled by a 1.3-fold lower number of induced double-strand breaks. The results suggest that p53 could have impact on chromatin compaction and thus effect DNA damage induction and radiosensitivity of tumour cells.

Adaptation, Physiological↗

PubMed2003

Hydrogen-induced self-organized nanostructuring of the Ir(100) surface.

We show that the Ir(100) surface forms a new nanostructure in a self-organized way when its reconstructed equilibrium surface is exposed to hydrogen. Scanning tunneling microscopy and quantitative low-energy electron diffraction retrieve that a long-range ordered superlattice of defect-free Ir chains with average lateral spacing of 1.36 nm and micrometer lengths develops. This can be used as a template for the formation of other nanostructures as is demonstrated.

Journal Article↗

PubMed2003

Mitochondrial proliferation in the permanent vs. temporary cold: enzyme activities and mRNA levels in Antarctic and temperate zoarcid fish.

Adjustments in mitochondrial properties and capacities are crucial in acclimatization to seasonal cold and in evolutionary cold adaptation of marine ectotherms. Although long-term compensatory increments in aerobic capacity of fish tissues have frequently been described in response to cold, much less is known about transitional phases and gene expression patterns involved. We investigated the time course of adjustment to acute cold in liver of eurythermal eelpout Zoarces viviparus. Whereas citrate synthase (CS) activity rose progressively in liver, cytochrome c oxidase (COX) activity was not altered during cold acclimation. Species-specific RNA probes were used to determine mRNA levels. CS mRNA (nuclear encoded) displayed a delayed, transient increase in response to cold, such that transcript levels did not parallel the change in enzyme activity. The enzyme activities and mRNA levels in the confamilial Antarctic Pachycara brachycephalum indicate cold compensation of CS activity in this cold-adapted species. The ratio of CS and COX activities was elevated in acclimation and adaptation to cold, indicating enhanced citrate synthesis over respiratory chain capacities in cold-adapted liver mitochondria. This may support enhanced lipid synthesis typically found in cold. The ratio of enzyme activity and transcript levels differed largely between Z. viviparus populations from the Baltic and North Seas, indicating the influence of unidentified parameters other than temperature. Transcript levels may not be tightly correlated with enzyme activities during thermal adaptation and thereafter. The time course of the acclimation process indicates that regulation at the translational and posttranslational levels predominates in adjustment to moderate thermal challenges.

Acclimatization↗

PubMed2003

Reduction of arteriosclerotic nanoplaque formation and size by fluvastatin in a receptor-based biosensor model.

Proteoheparan sulfate can be adsorbed onto a methylated silica surface in a monomolecular layer via its transmembrane hydrophobic protein core domain. Due to electrostatic repulsion, its anionic glycosaminoglycan side chains are stretched out into the blood substitute solution, thereby representing a receptor site for specific lipoprotein binding through basic amino acid-rich residues within their apolipoproteins. The binding process was studied by ellipsometric techniques suggesting that HDL has a high binding affinity and a protective effect on interfacial heparan sulfate proteoglycan layers with respect to LDL and Ca(2+) complexation. LDL was found to be deposited strongly at the proteoheparan sulfate-coated surface, particularly in the presence of Ca(2+), apparently through complex formation 'proteoglycan-low density lipoprotein-calcium'. This ternary complex build-up may be interpreted as arteriosclerotic nanoplaque formation on the molecular level responsible for the arteriosclerotic primary lesion. In a receptor-based biosensor application, this system was tested on its reliability to unveil possible acute pleiotropic effects of the lipid lowering drug fluvastatin. The VLDL/IDL/LDL and VLDL/IDL/LDL/HDL plasma fractions from a high risk patient with dyslipoproteinaemia and type 2 diabetes mellitus showed the start of arteriosclerotic nanoplaque formation at a normal blood Ca(2+) concentration, with a strong increase at higher Ca(2+) concentrations. Nanoplaque formation and size of the HDL-containing lipid fraction remained well below that of the LDL-containing lipid fraction. Fluvastatin, whether applied acutely to the patient (one single 80 mg slow release matrix tablet) or in a 2-month medication regimen, markedly slowed down this process of ternary aggregational nanoplaque build-up and substantially inhibited nanoplaque size development at all Ca(2+) concentrations used. The acute action gave no significant change in lipid concentrations of the patient. Furthermore, after nanoplaque generation, fluvastatin, similar to HDL, was able to reduce nanoplaque formation and size. These immediate effects of fluvastatin have to be taken into consideration when interpreting the clinical outcome of long-term studies.

Adsorption↗

PubMed2003

Longitudinal evaluation of serum estradiol and estrone in male patients infected with the human immunodeficiency virus.

In patients with human immunodeficiency virus (HIV) infection alteration of various endocrine functions have been described. However, there is limited information available on estrogens and their function in these patients. The aim of this study was to evaluate the pituitary and testicular endocrine markers: 14 HIV-positive men were included into the longitudinal study with a follow up to of 18 month period. None of the patients had a history or clinical evidence of endocrine dysfunction. Follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, estrone, estradiol, and testosterone were measured in serum by commercially available radioimmunoassays. Prolactin levels were not affected in the patients. LH and FSH remained within normal range, but at the end of the study period we observed a significant increase of LH (p < 0.05). In addition, testosterone levels were normal with a slight reduction at the end of the 18-month observation period (p <0.05). Both estrone and estradiol were significantly increased with a further rise at the end of the study (p <0.05). In summary, the elevation of the serum estrone and estradiol in HIV-afflicted patients correlated with the progress of the HIV-disease, being paralleled by a decrease in testosterone. The altered relation of estrogens and testosterone may in a part be responsible for the complaints of decreased libido and increased impotence often observed in HIV-infected men.

Adult↗

PubMed2003

[Intra-arterial lysis therapy in acute limb ischemia. Technical possibilities and limits of indication].

Acute limb ischemia is associated with a high risk of death and loss of the extremity. To restore the blood flow, several percutaneous thrombolytic techniques were developed. To achieve a targeted thrombus infiltration, the continuous application of low-dose urokinase or recombinant tissue plasminogen activator using a specific lysis catheter with sideholes is preferable. Concerning the amputation-free survival, thrombolysis is superior to surgery for occlusions of native vessels or bypass grafts that are not older than 2 weeks. Furthermore, the percutaneous approach permits the simultaneous treatment of the underlying lesion by angioplasty or stent implantation after dissolution of the occluding thrombus. The higher risk of complications must be balanced against risks of surgery in each patient.

Acute Disease↗

PubMed2003

[Interstitial Nd:YAG laser therapy. Color-Doppler imaging (CDI)-guided laser therapy of hemangiomas and vascular malformations].

BACKGROUND AND OBJECTIVE: Ultrasound-(US-) guided Nd:YAG laser therapy has been reported to be promising among different other options for treatment of hemangiomas and vascular malformations. The concept of CDI-guided interstitial laser therapy is therefore a further development based on the above mentioned therapeutic regime. PATIENTS AND METHODS: We examined 55 patients suffering from vascular lesions of different localization and extent pre-, intra-, and post-operatively using color-Doppler imaging (CDI). All vascular lesions were classified due to their vascularization pattern. As accurate diagnosis was imperative we decided on possible laser treatment depending on the CDI-classification. RESULTS: Intra-operative use of CDI rendered possible fiber-guidance by sonographic navigation and therefore precise treatment of aberrant vessels and well-perfused tumor areas. In 34 cases (62%) we observed complete, in 21 cases (38%) partial regression of vascular lesions. CDI allowed post-operative proof of diminution of tumor vascularization in all cases. CONCLUSIONS: CDI-guided interstitial Nd:YAG laser therapy is a minimally-invasive technique which allows replacement of conventional surgical procedures while achieving good cosmetic and functional results.CDI broadens the therapeutic possibilities in contrast to the former therapeutic concept of US-guided laser therapy due to pre-, intra and post-operative utilization of this imaging technique while significantly diminishing the intra-operative risk for the patient.

Adolescent↗

PubMed2003

[Disorder attribution in psychiatric problems of adolescents. A pilot study of inventory validation of disorder attribution of psychiatric problems in adolescents].

OBJECTIVES: The first Questionnaire on Disorder Concepts for Mental Problems in Adolescents (SPPJ) was developed on the basis of the attributional theory (health locus of control) and validated in a population of 54 adolescents with mental disorder hospitalized primarily as in-patients. METHODS: Analysis of consistency, correlation with the test for locus of control in health and illness (KKG-Test), scale intercorrelation, correlation with the Frankfurt Self-Concept Scales, therapy cooperation and prognosis. RESULTS: The SPPJ distinguishes between causal attributions and locus of control and proves to be a reliable measuring instrument that delivers satisfactory correlations to the statement of general measuring instruments (KKG-Test). Contrary to our expectations there is no significant positive correlation between internal locus of control and cooperation and prognosis. An external, powerful-others causal attribution has a negative effect upon cooperation, while an external powerful-others locus of control has a positive effect upon it. CONCLUSIONS: Adolescent self-assessment of mental problems is a defined research subject different from illness or health concept variables in adults or concerning bodily illness. Adolescents who are less inclined to blame others for their problem and who value professional competence are probably more accepting of interventions and more compliant. Further research in this area is necessary. On the basis of the attributional theory more attention must be paid to the substantial difference between locus of (treatment) control and causal attributions.

Adolescent↗

PubMed2003

Racemic ketamine does not abolish cerebrovascular autoregulation in the pig.

BACKGROUND: Little is known about the influence of racemic ketamine on autoregulation of cerebral blood flow (CBF), and available reports regarding its influence on cerebral hemodynamics are contradictory. This study was designed to evaluate cerebrovascular responses to changes in the mean arterial pressure (MAP) during ketamine anesthesia. METHODS: In eight normoventilated pigs anesthesia was induced with propofol and maintained by i.v. infusion of ketamine (15.0 mg kg(-1) x h(-1)) during measurements. The intra-arterial xenon clearance technique was used to calculate CBF. Balloon-tipped catheters were introduced in the inferior caval vein and mid-aorta, and increases or decreases by up to 40% in mean arterial pressure (MAP) in random order were achieved by titrated inflation of these balloon catheters. Cerebral blood flow was determined at each MAP level. Regression coefficients of linear pressure-flow curves were calculated in all animals. RESULTS: From the mean baseline level (101 mmHg) MAP was reduced by 20% and 40%, and increased by 26% and 43%. The maximal mean increase and decrease in MAP induced a 12% increase and a 15% decrease, respectively, of CBF from the mean baseline level (52.6 ml.100 g(-1) x min1). The 95% confidence interval (-0.02; 0.38) of the mean regression coefficient of individual pressure-flow curves does not include the regression coefficient (0.64) of a linear correlation between MAP and CBF including origo (correlation coefficient 0.99), which indicates complete lack of cerebrovascular autoregulation. CONCLUSIONS: We conclude that autoregulation of CBF is not abolished during continuous ketamine infusion in normoventilated pigs and that previous divergent conclusions are unlikely to be associated with severe impairment of cerebrovascular autoregulation.

Analgesics, Opioid↗

PubMed2003

[Chronic tinnitus and allergies -- are they linked?].

BACKGROUND: Some neuro-otologic disorders are suspected to have a higher prevalence of allergies than is found in the population. This study aimed to determine the prevalence of allergies in patients with chronic tinnitus. METHODS AND PATIENTS: 102 tinnitus patients were mailed a survey containing a list of allergies, and asked to quote any allergy they were afflicted with. Additionally, they had to specify whether the diagnosis has been medically confirmed or not. Findings were compared to those from an age- and gender-matched control group. RESULTS: 32 % of tinnitus subjects (CI (95 %) = 42 - 24 %), but only 21 % of controls (CI (95 %) = 29 % - 13 %) had at least one medically diagnosed allergy. Regarding all (ie., diagnosed and non-diagnosed) allergies, 49 % of tinnitus subjects (CI (95 %) : 39 -59 %) versus 46 % (CI (95 %) : 37 -57 %) of controls stated to be afflicted with at least one allergy. CONCLUSIONS: Our findings suggest that the frequency of allergies in tinnitus patients is essentially equal to the allergy prevalence in the population as revealed from recent epidemiologic studies. We conclude that there is no increased risk for allergies in chronic tinnitus. The lower rate of medically diagnosed allergies in non-tinnitus subjects probably indicates that mild allergies are less frequently diagnosed in the group of otherwise healthy persons.

Adult↗

PubMed2003

Occupational skin disease in the construction industry.

BACKGROUND: Construction workers have a substantial risk of developing irritant and/or allergic contact dermatitis. Unfortunately, however, there is little population-based epidemiological data relating to occupational skin diseases (OSD) in the European construction industry that allow assessment of preventive measures. OBJECTIVES: In this investigation, the yearly incidence rates and causes of OSD in the construction industry were analysed on the basis of our register in Northern Bavaria. METHODS: From 1990 until 1999, all incidences of OSD in the construction industry were recorded prospectively. This enables the calculation of incidence rates of OSD in relation to the employed population in Northern Bavaria as recorded by the German Federal Employment Office. RESULTS: In the construction industry, a total of 335 OSD were registered. These comprise 9.0% of all OSD in the register. We classified them into four relevant groups: (A) tile setters and terrazzo workers (incidence per 10 000 employees = 19.9); (B) painters (7.8); (C) construction and cement workers (5.2); and (D) wood processors (2.6). The overall incidence was 5.1 per 10 000 employees over 10 years, which is a little below average for the entire register (6.7). Of these, 43.6% were at least 40 years old. Allergic contact dermatitis (61.5%) occurred more often than irritant contact dermatitis (44.5%). Potassium dichromate caused roughly half of all cases of sensitization found to be occupationally relevant in the construction industry (152 cases) followed by epoxy resin (40) and cobalt chloride (32). CONCLUSIONS: The results indicate that potassium dichromate is still the most important allergen in the construction industry of Northern Bavaria; there has been no significant decline during the 1990s. This contrasts with the Scandinavian countries, where the prevalence of potassium dichromate sensitization declined following the reduction of chromium VI levels resulting from the addition of ferrous sulphate to cement. Within the construction industry, tile setters and terrazzo workers have a strikingly high incidence of OSD.

Adult↗

PubMed2002

Isospin mixing between low-lying states of the odd-odd N = Z nucleus 54Co.

Isospin mixing of the recently discovered doublet of 4(+) states with isospin quantum numbers T = 0 and T = 1 in 54Co is analyzed. It is shown that the measured E2/M1 multipole mixing ratios can be used to estimate the isospin mixing of these states. Combining the new experimental data with results of a shell model calculation, the amount of isospin mixing is found to be approximately 0.2%.

Journal Article↗

PubMed2002

Occupational relevance of positive standard patch-test results in employed persons with an initial report of an occupational skin disease.

OBJECTIVES: It is commonly accepted that the standard screening tray is an essential diagnostic test in patch testing supporting the diagnosis of contact dermatitis, the most common type of occupational skin disease (OSD). In this study standard patch-test results of employed persons with an initial report of an OSD were analyzed within 24 occupational groups. METHODS: An evaluation was made of employed persons recorded in the Register of Occupational Skin Diseases in Northern Bavaria (Berufskrankheitenregister Haut-Nordbayern; BKH-N) between 1990 and 1999, catering for those standard screening tray allergens tested over the 10-year period. RESULTS: Nickel sulfate was the most common sensitizer (29.5%), showing occupational relevance in only 11% of the cases sensitized. Other common sensitizers were cobalt chloride (13.5%), p-phenylenediamine free base (10.7%), potassium dichromate (9.8%), fragrance mix (5.4%), thiuram mix (4.2%), balsam of Peru (4.0%), chloromethylisothiazolinone/methylisothiazolinone (4.0%), and formaldehyde (4.0%). The most occupationally relevant sensitizers were thiuram mix (71%), epoxy resin (67%), p-phenylenediamine free base (59%), p-phenylenediamine-black-rubber mix/ N-isopropyl- N'-phenyl- p-phenylenediamine (53%), potassium dichromate (48%), formaldehyde (38%), chloromethylisothiazolinone/methylisothiazolinone (37%), and mercapto-mix/mercaptobenzothiazole (35%). Occupational groups at risk of acquiring delayed-type sensitization were, in particular, electroplaters, tile setters and terrazzo workers, construction and cement workers, solderers, wood processors, and leather and fur processors. CONCLUSIONS: The standard series contributes valuable information and asserts its position in clarifying the causes of OSDs. Based on the study results, the rate of occupationally relevant sensitization to each single allergen is demonstrated, and the difficulties in verifying the occupational relevance are discussed.

Adult↗

PubMed2002

Viral dynamics of early HIV infection in neonatal macaques after oral exposure to HIV-2287: an animal model with implications for maternal-neonatal HIV transmission.

A model of vertical HIV transmission was developed using oral HIV-2(287) exposure of newborn Macaca nemestrina. The minimal Animal Infectious Dose for this oral route was found to be 10-fold higher than that for atraumatic viral transmission across other mucosal membranes (vaginal/rectal) of juvenile macaques. However, once infection was established, viral replication was rapid and plasma viremia could be detected by reverse-transcriptase polymerase chain reaction and viral co-culture within 1 week following exposure. No animal was resistant to infection and all macaques initially exposed to a subinfectious viral inoculum were subsequently infected by re-exposure of mucosal membranes. Higher viral load during primary infection correlated with a more rapid CD4 depletion; however, all HIV-2(287)-infected animals developed CD4 depletion during the observation period. This animal model can now be used to study early viral replication in the presence and absence of anti-retroviral agents to help identify conditions to reduce vertical HIV transmission in human newborns.

Animals↗

PubMed2002

MAP kinase 1/2 (Erk 1/2) and serine/threonine specific protein kinase Akt/PKB expression and activity in the human corpus cavernosum.

Nitric oxide (NO) is an important mediator in the cavernosal smooth muscle relaxation that causes erections. The purpose of this study was to examine the existence, distribution and phosphorylation stage of two recently discovered key enzymes for NO regulation in human cavernosal tissue, the MAP Kinase 1/2 (Erk 1/2) and the serine/threonine specific protein kinase Akt/PKB. The expression of the enzymes was examined in corpus cavernosum specimens taken from both potent men and from patients with long-term impotence. There was a distinct difference in the activation stage of the MAP Kinase 1/2 (Erk 1/2) between endothelium and smooth muscle cells in potent patients. This finding gives evidence for a cell-type-specific regulation of the eNOS-dependent NO release. Furthermore, we found a higher basal level of active MAP Kinase 1/2 (Erk 1/2) in impotent patients. This finding gives the first evidence for an inhibitory influence of MAP Kinase 1/2 (Erk 1/2) on cavernosal eNOS activity.

Adolescent↗