Ethanol infusion increases ANP and p21 gene expression in isolated perfused rat heart

Whether alcohol-induced heart failure is caused by a direct toxic effect of ethanol, metabolites, or whether it is a secondary result of neurohumoral, hormonal, or nutritional factors is not clear. To address this question a Langendorff retrograde coronary perfusion model of rat heart was used to study the effect of 0.5% (v/v) ethanol (n = 7) and 0.5 mM acetaldehyde (n = 9) on left ventricular expression of ANP, BNP, p53, p21, TNF-alpha,bax, bcl-2 as well as on DNA-fragmentation. Ethanol infusion of 150 min duration significantly induced both ANP and p21 mRNA expression of ventricular myocardium compared with hearts infused with vehicle (n = 8). Acetaldehyde did not exert any significant effects on any of the parameters studied, although the mean expression of TNF-alpha tended to be lower in the acetaldehyde-treated hearts than in control hearts. No evidence of increased DNA-fragmentation was found in ethanol or acetaldehyde treated groups. We conclude that ethanol per se is capable of inducing genes associated with hypertrophy and impaired function of the heart whereas a significant apoptosis is not involved in the initial phase of alcohol-induced cardiac injury.

The effect of androgen status on skeletal muscle myosin heavy chain mRNA and protein levels in rats recovering from immobilization

Immobilization rapidly alters skeletal muscle. The aim of the present study was to determine whether testosterone administration or, in contrast, hypogonadism affects the recovery of muscle mass and myosin heavy chain (MHC) profile at both the mRNA and protein level, after 1 week of immobilization. Male rats were assigned to one of five groups: control (C), hindlimb-immobilized (IMM), and recovery (REC; where animals were allowed 2 weeks of free cage-activity after immobilization). The recovery group was further divided to eugonadal (REC-C), castrated (REC-GDX), and a testosterone-treated (REC-T). In all groups except REC-T, the body masses after immobilization were smaller than in C, although after immobilization the body mass in REC-T recovered at a slower rate than in the other two REC groups. The gastrocnemius mass and the amount of type IIa MHC mRNA decreased during immobilization, but the control levels were regained after recovery. The amount of type IIb mRNA was reduced in REC-GDX compared to C and IMM. The changes in the relative distribution of MHC mRNA were in line with these results. After recovery, the proportion of type IIx MHC protein increased and type IIb protein decreased, although in REC-T the changes were not statistically significant. The proportion of type IIa MHC protein increased only in REC-GDX. In summary, during recovery from immobilization it seems that muscle mass increases and the MHC mRNA and protein profile tend to change toward a slower phenotype, primarily as a result of the decrease in type IIb MHC. However, these changes occur rather independently of the testosterone status.

Myosin heavy chain mRNA and protein distribution in immobilized rat skeletal muscle are not affected by testosterone status

The effects of testosterone treatment and gonadectomy on myosin heavy chain (MHC) messenger RNA (mRNA) and protein expression after 1 week's immobilization were studied in male rat gastrocnemius muscle. In the testosterone-treated group silastic testosterone capsules were implanted subcutaneously before immobilization. The gonadectomized animals were castrated at 5 weeks of age. One group of eugonadal animals served as the immobilized control group, and another as the sedentary control group. Immobilization was performed at 9 weeks of age by bilateral hindlimb casting. The body and muscle masses, and the amount of type IIa MHC mRNA decreased significantly (P<0.01) in the immobilized animals by approximately 30, 40 and 50%, respectively, regardless of the serum testosterone levels which ranged from 1.1+/- 0.4 to 59+/-14 nmol L(-1). In the immobilized testosterone-treated group the proportion of type IIx MHC mRNA increased to 14% of the total MHC mRNA (P=0.02, compared with control). The MHC protein distribution did not change significantly. There were no significant differences in any parameters between the three immobilized groups. In conclusion, neither the lack nor excess of testosterone significantly altered the changes caused by immobilization. Therefore, it seems that lack of mechanical loading is a far more important determinant of MHC expression than the male sex hormone status.

Role of acetaldehyde in the induction of heart left ventricular atrial natriuretic peptide gene expression in rats

We studied the effects of ethanol and acetaldehyde on myocardial gene expression of atrial natriuretic peptide (ANP) and growth of rats. Combined ethanol and calcium carbimide treatment increased blood-acetaldehyde levels and ANP mRNA levels by 40-60% in 2-8 day experiments, compared to the controls. The results suggest a role for acetaldehyde in the development of alcoholic heart dysfunction.

Molecular characterization of McArdle's disease in two large Finnish families

We have studied two large unrelated Finnish families with myophosphorylase deficiency (McArdle's disease). In one, we identified a new nonsense mutation at codon 540 in exon 14 of the myophosphorylase gene, changing an encoded glutamic acid to a stop codon (E540X). The second family carried a splice-junction mutation at the 5' splice site of intron 14 (1844+G-->A), previously reported in one Caucasian patient and in a consanguineous Druze family. These data further enlarge the list of mutations associated with McArdle's disease and establish that McArdle's disease is genetically heterogeneous also within the Finnish population.

Metabolic causes of recurrent rhabdomyolysis

OBJECTIVES

The aim of the study was to evaluate the biochemical causes of recurrent rhabdomyolysis in Finland.

MATERIAL AND METHODS

We examined 22 patients with recurrent rhabdomyolysis, and 26 patients with one episode of rhabdomyolysis or other symptoms compatible with metabolic myopathy. Muscle histopathology and activities of phosphorylase (PHRL) (total and active), phosphofructokinase (PFK), carnitine palmitoyltransferase (CPT) and myoadenylate deaminase (MAD) were studied. The limit of enzyme deficiency was defined as enzyme activity less than 5% of the mean of the control subjects.

RESULTS

We found 4 patients with muscle PHRL deficiency, 1 patient with PFK deficiency and 1 patient with evidence of phosphorylase kinase deficiency. One patient had Becker's muscle dystrophy, 2 patients had unspecified dystrophies, 1 patient had Miyoshi myopathy, and 1 patient had a form of mitochondrial encephalomyopathy (MELAS).

CONCLUSION

Enzyme defects were found in 23% of the patients with recurrent rhabdomyolysis. Other muscle diseases, muscular dystrophies or myopathies, were detected in 18% of these patients, emphasizing the value of clinical and histopathological examination of patients with previous rhabdomyolysis.

Expression of cyclooxygenase-2 in human gastric carcinoma

Epidemiological studies suggest that the use of aspirin decreases the incidence of and mortality from gastrointestinal cancers. The best known target of aspirin and other nonsteroidal anti-inflammatory drugs is cyclooxygenase (Cox), the rate-limiting enzyme in the conversion of arachidonic acid to prostanoids. Two Cox genes have been cloned, of which Cox-2 is an inducible immediate-early gene. It is still unknown how nonsteroidal anti-inflammatory drugs act as chemopreventive agents, but they may target Cox-2. Cox-2 mRNA and protein were recently found to be expressed in human colon carcinoma. We have now studied the expression of Cox-2 in human gastric adenocarcinoma tissues which contained significantly higher levels of Cox-2 mRNA when compared with paired gastric mucosal specimens devoid of cancer cells. In contrast, Cox-1 mRNA levels were not elevated in the carcinoma. However, Cox-2 mRNA was not expressed in mucinous ovarian carcinoma samples as detected by Northern blot hybridization. Immunohistological detection of Cox-2 protein showed cytoplasmic staining in the gastric carcinoma cells but not in the surrounding stroma. Some hyperplastic glands showed intense staining, whereas glands of normal morphology were negative. Our data thus suggest that Cox-2 is expressed by human gastric adenocarcinoma.

Myosin heavy chain mRNA transform to faster isoforms in immobilized skeletal muscle: a quantitative PCR study

A quantitative polymerase chain reaction (PCR) method was used to measure the quantities of type I, IIa, IIx, and IIb myosin heavy chain (MHC) mRNA in total RNA preparations of the soleus, gastrocnemius, and plantaris muscles of normal and hindlimb-immobilized rats. Type IIx and even type IIb MHC mRNA were demonstrated at extremely low levels in normal soleus, 2.1 +/- 0.4 x 10(5) and 5.0 +/- 0.2 x 10(5) molecules of mRNA per microgram total RNA, respectively. Immobilization for 1 wk significantly altered the gene expression of MHC isoforms. In soleus, both type IIx and IIb MHC genes became significantly upregulated, 24-fold (P < 0.005) and 2.6-fold (P < 0.05), respectively. In gastrocnemius, the level of type IIa MHC mRNA decreased by 51% (P < 0.01) and the level of type IIx MHC mRNA increased by 140% (P < 0.05). In plantaris, the level of type IIa MHC mRNA decreased by 58% (P < 0.005). In conclusion, immobilization changed the MHC mRNA profile in three different types of skeletal muscle toward faster isoforms. The quantitative results permit reliable evaluation of changes in mRNA levels.