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Biomedical subjects

V R Preedy

Publications and source records attributed to V R Preedy.

At least 163 records · Page 9Linked to original sources
PubMed1991

Effect of acute anaesthesia on synthesis of contractile and non-contractile proteins of heart muscle and mixed proteins of types I and II fibre rich skeletal muscles of rat.

STUDY OBJECTIVE: The aim of the study was to determine whether the deleterious effects of anaesthesia on cardiac muscle function were due to disturbance of protein synthesis. Comparative investigations were made on anaerobic and aerobic skeletal muscles, and plasma insulin and growth hormone levels were also measured to see if these were mediating factors. DESIGN: Rats were subjected to acute methoxyfluorane anaesthesia for 10 min. At the end of the study they were killed and plasma growth hormone and insulin were measured. Rates of cardiac and skeletal muscle protein synthesis were also determined with a flooding dose of L[4-3H]phenylalanine. EXPERIMENTAL MATERIAL: Muscle samples were obtained from male Sprague-Dawley rats, weight 191-222 g. MEASUREMENTS AND MAIN RESULTS: Anaesthesia reduced the fractional rate of myocardial mixed protein synthesis and synthesis relative to RNA (p less than 0.05). The anaesthesia induced decrease in the synthesis rates of cardiac contractile proteins (p less than 0.05) was greater than the decrease in the non-contractile protein fractions (p greater than 0.05). Soleus (aerobic, Type I) and plantaris (anaerobic, Type II) muscle rates of protein synthesis were unaltered in response to anaesthesia (p greater than 0.05). Plasma insulin concentrations increased in response to acute anaesthesia (p less than 0.05), but the insulin effect was depressed by the flooding dose of phenylalanine (p less than 0.05). Plasma growth hormone levels were not altered in response to anaesthesia (p greater than 0.05). Thus, the changes in cardiac protein synthesis could not be ascribed to these hormones. CONCLUSIONS: Synthesis of cardiac contractile proteins is selectively sensitive to the effects of acute anaesthesia even in the presence of high plasma insulin concentrations. The fall in cardiac protein synthesis may be a result of the negative inotropic effects of general anaesthesia.

Anesthesia, General↗
PubMed1991

The urinary excretion of the collagen degradation markers pyridinoline and deoxypyridinoline in an experimental rat model of alcoholic bone disease.

(1) The effect of chronic (6 weeks) ethanol feeding on whole-body skeletal tissue in the rat was studied by analysis of the urinary pyridinium crosslinks of collagen, pyridinoline (PYD; found predominantly in the collagens of cartilage and bone and to a lesser extent in other tissues) and deoxypyridinoline (DPD; found only in type I collagen of bone and dentine). (2) The urinary concentrations of total, free and conjugated PYD were unaltered by ethanol feeding. In contrast, there were significant reductions in total and conjugated DPD concentrations. The reduction in the concentration of free DPD did not achieve statistical significance. The urinary PYD/DPD molar ratios, of total and conjugated forms, were increased. (3) Alcohol feeding caused the total 24 hr urinary PYD excretion to fall slightly, by 15%. There were no statistically significant effects on excretion of free and conjugated forms of PYD, nor on the free/total, free/conjugated and conjugated/total molar ratios. In contrast, the 24 hr urinary excretion of total, free and conjugated DPD was significantly reduced by 25-55%. Furthermore, the free/total and free/conjugated molar ratios were significantly increased by 40% and 80%, respectively, and the conjugated/total molar ratio was significantly reduced by 16%. (4) Data from the analysis of plasma electrolytes, enzymes and metabolites did not support the contention that the effects on collagen degradation were a result of secondary organ dysfunction due to alcohol consumption. (5) The results suggest that chronic ethanol feeding for 6 weeks is having a primary effect on skeletal tissue. A reduction in the absolute rate of bone resorption is implicated and ethanol may inhibit the normal formation of the mature crosslinks.

Alcoholism↗
PubMed1991

The effect of chronic alcohol ingestion on whole body and muscle protein synthesis--a stable isotope study.

The cause of the proximal myopathy associated with chronic alcohol ingestion has yet to be established. The clinical feature of muscle wasting implies either inhibited skeletal muscle protein synthesis, stimulated breakdown or a combination of both. Previous data suggest that breakdown is reduced, rather than promoted. This provides evidence, albeit indirect, that the myopathy is the result of inhibited muscle protein synthesis, which has been demonstrated recently in the rat model. We have examined the influence of chronic alcohol intake on post-absorptive fractional skeletal muscle protein synthesis in man using a primed continuous (1 mg/kg/hr) infusion of L-[1-13C]leucine for 8 hr. Percutaneous quadriceps muscle biopsies (200 mg) were taken after 2 and 8 hr of the infusion for measurement of the incorporation of 13C leucine into muscle protein. Plasma 13C enrichment of alpha-ketoisocaproic acid, the deaminated product of leucine, was used to represent that of the precursor pool. We studied 6 fully ambulant alcoholics, who exhibited no overt evidence of skeletal muscle disease and who had consumed at least 100 g alcohol daily for a minimum of 10 years. Mean (+/- S.D.) fractional muscle protein synthesis was 0.0274 +/- 0.0087 (95% confidence intervals 0.0204-0.0344%/hr). This value is significantly lower than recently published control values obtained using identical protocols which range from 0.046 to 0.055%/hr. In addition, whole body leucine oxidation was lower (P less than 0.05) in the chronic alcoholics than in healthy controls, whereas neither whole body protein synthesis nor breakdown was significantly reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Contractile and non-contractile proteins and nucleic acids in the stomach, whole jejunum and seromuscular layers of the duodenum, jejunum, ileum and large intestine in response to chronic ethanol feeding.

Rats were fed a nutritionally adequate liquid diet containing 35% of the total calories as ethanol (treated), or identical amounts of the same diet in which ethanol was replaced with isocaloric glucose (controls). At 6 weeks, rats were killed and the stomach (cardiac region), duodenum, jejunum, ileum and the large intestine (combined colon and rectum) were dissected. Seromuscular layers were prepared from the duodenum, jejunum, ileum and the large intestine. After 6 weeks of chronic ethanol feeding the wet weights of the stomach and whole jejunum were reduced by 31%. The wet weights of the duodenum, jejunum and distal ileum seromuscular layers were reduced by 19-25%. The wet weight of the large intestine seromuscular layer was unaltered. The total amounts of contractile and non-contractile protein in the small intestinal seromuscular layers were reduced by 16-52%. In jejunal serosa, the RNA contents were reduced by 29%, but total RNA contents in the serosa of the ileum and duodenum were not significantly altered. Total DNA content was reduced in jejunal and ileal serosal layers by 22 and 33%, respectively, but remained unchanged in duodenal serosa. In the stomach, total contractile and non-contractile protein was reduced by 26-52% and similarly total RNA and DNA were also decreased by 47 and 34%, respectively. Chronic ethanol feeding had no apparent effect on either contractile or non-contractile total protein, total RNA or DNA contents in colonic and rectal serosa. In the combined mucosal and seromuscular layers of the jejunum, much greater effects due to ethanol feeding were observed when compared with the jejunal seromuscular layer alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1991

The effect of aminoguanidine treatment, with or without food restriction on the liver, stomach and small intestine of the rat.

A comparative investigation has been made into the effects of aminoguanidine treatment (60 mg kg-1 day-1) with or without dietary restriction (i.e. 50% reduction in food intake) on the protein, RNA and DNA composition of the liver, small intestine and stomach of young rats (0.1 kg body weight). After 3 weeks of dietary restriction the wet weights of the liver and small intestine decreased by 56 and 52%, respectively. There were significant reductions (approx 50%) in total hepatic and intestinal protein, RNA and DNA. Changes in ratios of RNA/protein, RNA/DNA and protein/DNA were only significant for intestinal RNA/DNA, where a 15% reduction was observed. In contrast, stomach wet weight and total protein content were unaltered by dietary deprivation. Stomach RNA and DNA contents were reduced by only 18-21%, and the protein/DNA ratio increased by 22%. Similar responses of liver, small intestine and stomach to dietary deprivation were observed in aminoguanidine-treated rats. Aminoguanidine-treatment of rats on an unrestricted diet for three weeks had no effect on the wet weights, total protein, RNA or DNA contents of the liver, stomach or small intestine. In dietary-restricted rats, and stomach were unaffected by the treatment. However, aminoguanidine treatment of dietary-restricted rats caused significant increases in the amounts of intestinal protein, RNA and DNA by approximately 15%. The treatment abolished the dietary restriction-induced decrease in total intestinal DNA/body weight. The wet weights of the lung, diaphragm, kidney, spleen and testes of both fed and dietary-restricted rats were also unaffected by aminoguanidine.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1991

An investigation into the effects of aminoguanidine treatment on the plasma and blood of free-fed and dietary-restricted rats.

An investigation has been made into the effect of oral aminoguanidine (50-60 mg kg-1 day-1) on the blood biochemistry of male Wistar rats which either had free access to food or were dietary-restricted (50% of the food consumed by the free access group). In control rats (i.e. without aminoguanidine treatment) three weeks of food restriction caused significant increases in plasma sodium and albumin and the erythrocyte count, haematocrit and haemoglobin. There were reductions in plasma calcium, phosphate, alkaline phosphatase activity, urea, triglycerides, creatinine, glucose and the red cell volume. Similar effects of food restriction were observed in aminoguanidine-treated rats. Aminoguanidine ingestion in free-fed animals caused a reduction in plasma creatinine concentration. In dietary-restricted rats, aminoguanidine ingestion reduced plasma sodium and total plasma proteins (largely as a result of a decline in albumin), and increased plasma urea concentrations. Aminoguanidine was added to plasma of control rats in-vitro to determine whether it interfered with the assay of urea and creatinine. At concentrations of 0.1 to 10 mg mL-1, aminoguanidine had no effect on urea determinations. However, aminoguanidine significantly reduced the apparent concentration of plasma creatinine by between 7 to 81%. The changes in plasma analytes in aminoguanidine-treated rats may be indicative of minor hepatic perturbations or kidney function, but the data also imply that prior nutritional state is a determinant of aminoguanidine effects.

Animals↗
PubMed1991

Bone collagen, mineral and trace element composition, histomorphometry and urinary hydroxyproline excretion in chronically-treated alcohol-fed rats.

(1) We examined the possibility that enhanced fragility of the bony skeleton in alcohol abusers may be a consequence of a reduction in collagen composition. Male rats were fed a liquid diet containing 36% of total calories as ethanol; controls were pair-fed iso-caloric glucose. At 3, 7 and 14 days of treatment, collagen contents of tibia were unaltered, but small and significant reductions (15-30%) were observed at 28 and 42 days of treatment. Urinary hydroxyproline excretion was increased by 40-60% at 42 days of treatment, suggesting enhanced collagen degradation. (2) Bones of rats treated with ethanol for 42 days had significantly reduced mineral content (approximately 20%) with accompanying reductions in phosphate, calcium, copper and magnesium, but not sodium or potassium. Water content was unaltered, but tibial zinc and iron were increased by approximately 15%. (3) Histomorphometric analysis of bones taken at 42 days showed significant reductions in cortical bone thickness of lower tibia (by 28%). The thickness of the upper cortices and cancellous bone of the tibia was unaffected. Reductions in trabecular bone volume (approx. 25%) did not achieve statistical significance. (4) These observations are consistent with the known enhanced fragility of bones in alcoholic rats. The regional susceptibility of the tibia may be related to reduced load bearing as a result of muscle atrophy.

Alcohol Drinking↗
PubMed1990

Protein synthesis in liver and extra-hepatic tissues after partial hepatectomy.

Effects of partial hepatectomy on protein synthesis were defined in liver and extra-hepatic tissues of the mature rat. Studies were performed at 24 h and 48 h after surgery in the absence of the dietary input. Protein accretion in the regenerating liver preceded mitosis, but was accompanied by increases in RNA content and fractional rates of protein synthesis (ks). A positive relationship existed between protein-synthetic capacity and ks over the period of study. Increases in ks also bore a positive relationship with increases in translational efficiency. Extra-hepatic tissues showing decreased rates of protein synthesis after liver resection included kidney, striated muscles and brain. Effects were observed mainly at 24 h after surgery and resulted from decreased translational efficiency. Partial hepatectomy increased ks in diaphragm and tibia at both 24 h and 48 h after surgery. In diaphragm, there was net protein accretion, and, as in liver, increases in ks were due to increases in both protein-synthetic capacity and efficiency.

Animals↗
PubMed1990

Ethanol-induced smooth and skeletal muscle myopathy: use of animal studies.

This article reviews the effects of ethanol on skeletal and smooth muscle. A brief summary of its clinical effects is provided, with a rationale for the use of suitable animal models to study ethanol-induced myotoxicity. Practical details are given for the animal feeding techniques to examine the chronic effects of ethanol toxicity. Information on acute ethanol dosage experiments are also provided. Our results have indicated that ethanol causes net loss of both skeletal and smooth muscle protein and an effect on protein synthesis and/or degradation was implicated. The theoretical and practical basis of measuring protein synthesis in intact laboratory animals is reviewed. However, there are no reliable methods for measuring rates of protein breakdown in vivo. The combined results of our studies indicated that disturbances in protein synthesis were causal mechanisms for ethanol-induced myo-dysfunction. Acute ethanol exposure was largely characterised by reductions in fractional rates of skeletal and smooth muscle contractile protein synthesis. The dominant characteristics of chronic treatments were loss of skeletal and smooth muscle proteins and RNA. Further laboratory animal studies will eventually elucidate the molecular mechanisms of these changes and provide valuable information on the regulation of protein mass.

Actomyosin↗
PubMed1990

Aspects of protein metabolism after elective surgery in patients receiving constant nutritional support.

1. The present study was designed in an attempt to resolve conflicting views currently in the literature relating to the effect of surgery on various aspects of protein metabolism. 2. Sequential post-operative (2, 4 and 6 days) changes in whole-body protein turnover, forearm arteriovenous difference of plasma amino acids, glucose, lactate and free fatty acids, muscle concentration of free amino acids, RNA and protein, urinary nitrogen and 3-methylhistidine, plasma concentrations of insulin, cortisol and growth hormone, and resting metabolic rate, were measured in six patients undergoing uncomplicated elective total abdominal hysterectomy. 3. All patients received a constant daily diet, either orally or intravenously, based on 0.1 g of nitrogen/kg and an energy content of 1.1 times the resting metabolic rate for 7 days before and 6 days after surgery. 4. Whole-body protein turnover, synthesis and breakdown increased significantly 2 days after surgery (P less than 0.05) and returned towards pre-operative levels thereafter. 5. Forearm release of branched-chain amino acids and alanine, and efflux of glucose and lactate, were enhanced 4 days after surgery (P less than 0.05). Muscle glutamine and alanine concentrations were decreased on the fourth and sixth days after surgery (P less than 0.05). The RNA/protein ratio (indicating the capacity for protein synthesis) was unaltered. 6. A significant increase in urinary nitrogen and 3-methylhistidine was observed on days 3 and 4 after surgery (P less than 0.05). Thereafter, these parameters remained elevated, although failing to reach statistical significance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Alcohol and skeletal muscle disease.

Skeletal muscle myopathy is caused by prolonged ethanol misuse and affects between half and two-thirds of chronic alcohol misusers. This chronic myopathy is characterized by a selective reduction in Type II (fast twitch) fibre area; Type I (slow twitch) fibres are relatively unaffected. The myopathy is not mediated by the patients' corticosteroid and nutritional status, liver dysfunction or neurological changes, and there is little correlation between alcoholic myopathy and alcohol intake. However, plasma alpha-tocopherol and selenium levels in myopathic alcoholics are reduced. The myopathy may in some way be related to the reduced fractional rates of skeletal muscle protein synthesis that occur in alcohol misusers and implicates free radical reactions in the pathogenesis of the myopathy. We have established a rat model of chronic alcoholic myopathy. In this model anatomically distinct skeletal muscles were taken to represent Type I (i.e. soleus) or Type II (i.e. plantaris) fibres. There were selective losses of Type II muscle protein at the end of 6 weeks of ethanol feeding. These changes were also not apparently mediated by nutritional limitations, neurological changes or liver dysfunction. Skeletal muscle protein synthesis was also reduced, as was plasma alpha tocopherol and selenium levels. Thus the rat model is amendable for further work to elucidate the molecular mechanisms responsible for alcohol-induced muscle loss.

Alcoholism↗
PubMed1990

Liver histology, blood biochemistry and RNA, DNA and subcellular protein composition of various skeletal muscles of rats with experimental cirrhosis: implications for alcoholic muscle disease.

(1) Liver cirrhosis was induced in male rats by treatment with carbon tetrachloride and phenobarbitone for 130-142 days. Detailed histological examination showed all livers from rats treated with carbon tetrachloride had annular fibrosis, necrosis, loss of normal hepatic architecture and other features that were consistent with an established micronodular cirrhosis. (2) Plasma biochemical analysis showed a significant reduction in total protein concentration (13%), which was due entirely to a reduction in plasma albumin (29%). There were also large increases in the plasma activities of alkaline phosphatase (110%) and aspartate aminotransferase (159%), when compared to phenobarbitone-treated controls. Plasma cholesterol was also increased (67%), but other plasma analytes were not significantly altered. (3) The soleus (Type I), plantaris (Type II) and gastrocnemius (Types I and II) muscles were dissected and examined for possible differential effects. There were minor reductions in all three muscle weights, but these changes did not reach statistical significance. The protein, RNA and DNA concentrations, total muscle content and content relative to body weight in cirrhotic rats were also not significantly altered in any of the muscles. Cirrhosis did not cause any perturbations in derived parameters, i.e. amount of synthetic apparatus per cell, RNA/DNA ratio, apparent cell size, protein/DNA ratio and the capacity for protein synthesis or RNA/protein ratio. (4) The gastrocnemius was fractionated into soluble, stromal and myofibrillar proteins. The concentrations and contents of all three proteins were unaltered in cirrhotic animals, compared to controls. (5) It is concluded that in this experimental model of cirrhosis there were no effects on those skeletal muscle variables which are strikingly altered by chronic alcohol feeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1990

Protein synthesis in bone and skin of the rat are inhibited by ethanol: implications for whole body metabolism.

The acute effects of ethanol (75 mmol/kg body weight, intraperitoneal) on rates of protein synthesis in bone tibia) and skin of young (approximately 100 g body weight) laboratory rats was investigated. Plasma ethanol levels were raised to approximately 40 mmol/liter. At 2.5 hr, rates of protein synthesis were measured with a flooding dose of L-[4-3H]phenylalanine. In bone the protein-bound specific radioactivities, fractional synthesis rates, and synthesis rates relative to RNA and DNA were significantly reduced by approximately 30%. In skin these variables similarly decreased in response to ethanol treatment, by approximately 25%. The reduction in absolute rates of protein synthesis in bone (delta, 0.7 g protein/day/kg body weight) and skin (delta, 3.4 g protein/day/kg body weight) were comparable to the reductions in liver and skeletal muscle in response to acute ethanol. As bone and skin contribute to a quarter of whole body protein synthesis, it was concluded that these observations may have important implications for whole body protein homeostasis.

Animals↗
PubMed1990

Measurement of protein synthesis by the phenylalanine flooding dose technique: effect of phenylalanine and anaesthesia on plasma electrolyte, enzyme and metabolite levels.

Ten minutes after an intravenous flooding dose of phenylalanine to rats, plasma sodium and calcium concentrations were slightly reduced (by 2-7%) but no effects on potassium or phosphate were observed. Creatine kinase activities were significantly increased by phenylalanine injection (by 39%), but alkaline phosphatase, alanine aminotransferase, lactate dehydrogenase and aspartate aminotransferase activities were unaltered. Plasma concentrations of total proteins, albumin, cholesterol, triglycerides, urea, creatinine and glucose were also unaffected. In the presence of anaesthesia, phenylalanine injection had almost identical effects, although the increase in creatine kinase activities did not reach statistical significance. Anaesthesia for 10 min reduced plasma potassium concentrations (by 27%), and calcium (by 5%), though phosphate and sodium were unaltered. The activities of lactate dehydrogenase, creatine kinase and aspartate aminotransferase were reduced by between 36-52%, but alkaline phosphatase and alanine aminotransferase activities were unaltered by anaesthesia. Plasma concentrations of total proteins and albumin were also reduced (both by 9%), but glucose concentrations were increased (by 33%). Anaesthesia had no other significant effects on cholesterol, triglycerides, urea or creatinine concentrations. The qualitative effects of anaesthesia in the presence of raised free phenylalanine concentrations were similar. It was concluded that, except for creatine kinase, determinations of plasma constituents in phenylalanine-injected rats could be made without overt interpretational errors. However, caution is required in interpreting data on plasma constituents from anaesthetized rats.

Alanine Transaminase↗
PubMed1990

Protein synthesis of muscle fractions from the small intestine in alcohol fed rats.

The effects of chronic ethanol feeding on the amounts and synthesis rates of cytoplasmic, contractile, and stromal protein fractions were investigated in the small intestine of eight pairs of immature and seven pairs of mature rats. Treated rats were fed ethanol as 36% of total energy in a nutritionally adequate liquid diet. Paired controls were fed isovolumetric amounts of the same diet in which ethanol was substituted by isocaloric glucose. After six weeks the total cytoplasmic and contractile protein content in immature rats was reduced by 18% and 31%, respectively (p less than or equal to 0.007). The decline in the stromal protein content (26%) was not statistically significant (p = 0.130). In mature rats the protein contents were also reduced in the cytoplasmic (25%, p = 0.035) and contractile (27%, p = 0.005) protein fractions, though the stromal protein fraction was unaltered (p = 0.913). In immature rats fractional rates of protein synthesis in cytoplasmic and contractile protein fractions of the small intestine were unaltered by chronic ethanol feeding (p less than or equal to 0.853). In mature rats, the synthesis rates of corresponding fractions declined, by 18% and 31%, respectively, but were also not statistically significant (p less than or equal to 0.369). Absolute rates of protein synthesis in immature rats fell by 6% (p = 0.549) in the cytoplasmic and 31% in the contractile protein fraction (p = 0.045). In mature rats, the corresponding reductions were 38% (p = 0.106) and 48% (p = 0.033), respectively. Virtually no radioactivity could be detected in the stromal fraction, signifying very low synthesis rates. Chronic ethanol feeding reduces the amount of protein in the small intestine of the immature and mature rat with the contractile protein fraction showing the greatest decrease. In the absence of statistically significant reductions in fractional synthesis rates a partial adaptation in turnover rates may have occurred.

Animals↗
PubMed1990

Experimental alcoholic skeletal muscle myopathy is characterised by a rapid and sustained decrease in muscle RNA content.

An investigation was made into the effects of ethanol feeding (36% of total calories) on skeletal muscle. From 7 to 42 days, muscle weights and protein and DNA contents of alcohol-treated rats were significantly lower (10-23%) than pair-fed controls (with glucose as 36% of total calories). Ethanol feeding markedly reduced muscle RNA content by 22-34%, when compared to controls. Muscle RNA content of ethanol-fed rats at 7, 14, 28 and 42 days of treatment was significantly lower than initial values (i.e. at 3 days) by 22-38%. Thus, ethanol feeding caused an initial net loss and thereafter a reduction in the rate of accretion of RNA. The marked and sustained loss in the muscle protein synthetic apparatus may be a precipitating event in the development of experimental skeletal muscle myopathy.

Alcoholism↗
PubMed1990

Changes in protein, RNA and DNA and rates of protein synthesis in muscle-containing tissues of the mature rat in response to ethanol feeding: a comparative study of heart, small intestine and gastrocnemius muscle.

1. The relative sensitivity of heart, small intestine and skeletal muscle to chronic ethanol feeding was investigated in mature Wistar rats fed ethanol as 36% of total energy intake; controls were fed the same diet in which ethanol was substituted by isoenergetic glucose. 2. Chronic ethanol feeding had no apparent effect on the protein, RNA and DNA contents of heart homogenates (atria and ventricles). The ratios of RNA/protein (synthetic capacity), RNA/DNA (synthetic material per nucleus) and protein/DNA (DNA-unit or apparent cell size) were also unaltered in the hearts of alcohol-fed rats. Fractional rates of cardiac protein synthesis (ks), and synthesis relative to RNA (kRNA) and DNA (kDNA) and absolute rates of protein synthesis (Vs) were unaffected by ethanol feeding. The total content of cardiac soluble proteins was unaltered by chronic ethanol feeding, but there were small and statistically significant decreases in the contents of the myofibrillar and stromal protein fractions. There were no differences in ks in any of the cardiac subcellular protein fractions. 3. In the small intestine, ethanol feeding had no statistically significant effect on either protein or RNA contents, but there was an apparent increase in RNA when expressed relative to either protein or DNA, though the DNA-unit was unaltered. There were also substantial decreases in ks, kRNA, kDNA and Vs of approximately 15-35%. 4. In the gastrocnemius, RNA contents were significantly reduced by ethanol feeding but protein and DNA contents were unaffected. Indices of the synthetic capacity and synthetic material per nucleus were also reduced, but the DNA-unit was unaltered. These observations were accompanied by approx. 15-30% reductions in ks, kRNA, kDNA and Vs in response to ethanol feeding. 5. It is concluded that various aspects of protein metabolism in the heart, small intestine and skeletal muscle are adversely affected by chronic ethanol toxicity. The characteristics and magnitude of the responses in each tissue differ. Effects in the heart may be subtle, though haemodynamic indices may ensue. The ethanol-induced alterations in the small intestine and skeletal muscle may be responsible for gastrointestinal disturbances in motility and skeletal muscle weakness, respectively.

Alcoholism↗