Enzyme activities in plasma, kidney, liver, and muscle of five avian species

Activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), creatine phosphokinase (CPK), and lactate dehydrogenase (LDH) were determined in plasma, kidney, liver, and muscle from five species of captive birds. Few differences occurred in plasma activities between sexes but considerable differences occurred between species. All five enzymes were detected in each of the tissues sampled. Relative enzyme activities in liver, kidney, and muscle were similar for each species. CPK activity was much higher in muscle than in liver or kidney and, of the five enzymes studied, may be the best indicator of muscle damage. Most of the other enzymes were more evenly distributed among the three tissues, and no organ-specific enzyme could be identified for liver or kidney. Because of interspecific variations in plasma enzyme activities, it is important to establish baseline values for each species to ensure accurate interpretation of results.     

Effects of endurance exercise on serum enzyme activities in the dog, pig and man.

Daily levels of GOT, GPT, AK and LDH did not change consistently with exercise in any species. The level of CPK each day before exercise presented a consistent rise during the week of exercise in the dog and man but not in the pig. By the third day of resting, all enzyme activities were at control levels. The probable tissue of origin for AK and LDH at rest as well as after exercise was the heart, liver, skeletal muscle and kidney in all three species. Serum CPK was the most sensitive index of acute exercise stress in the trained dogs and men. We have shown that the pig, which exhibits responses to exercise resembling those of man, can be exercise trained. The pig may, therefore, be the more appropriate model for endurance exercise studies.     

Blood and liver enzymes in rainbow trout (Salmo gairdneri Rich.) with emphasis on their diagnostic use: Study of CCl4 toxicity and a case of Aeromonas infection

The effect of one intraperitoneal injection of 1.33 ml of CCl₄ per kg of fish was studied. Two experimental series were performed and studied for 10 days (with diluent) and 24 h (pure CCl₄) periods. LDH, GOT, GPT, GR, GDH, CPK, G-6-Pase, and AlkPase were studied. The activity of all enzymes in blood increased: LDH (four times the control), GOT (two times), GPT (three times); they reached a maximal activity 12 h after injection of diluted CCl₄. The levels of some enzymes were also examined in the liver. With pure CCl₄, maximal enzyme activity in blood occurred earlier (6 h). A 6 to 10 times increase was observed for GOT, GPT, LDH, GR, and GDH. Histopathological observations were correlated with these enzymes studies.
An Aeromonas disease characterized by the destruction of the dermis, the exposure of the muscle, and by the presence of numerous petechiae in the liver enabled us to examine the relationships between naturally induced tissue damage and enzyme levels in blood. The levels of seven blood enzymes were determined and the most significant modifications were observed for LDH and CPK. which increased their concentration from 3 to 7 times respectively. A pyruvate saturation test demonstrated that LDH was probably from liver as it was observed after CCl₄ poisoning. The contribution of such biochemical studies in fish research is evaluated.     

Acute stress-induced tissue injury in mice: differences between emotional and social stress

Emotional stress affects cellular integrity in many tissues including the heart. Much less is known about the effects of social stress. We studied the effect of emotional (immobilization with or without cold exposure) or social (intermale confrontation) stress in mice. Tissue injury was measured by means of the release of enzyme activities to blood plasma: lactate dehydrogenase (LDH), creatine kinase (CK), aspartate transaminase (AST), and alanine transaminase (ALT). Tape-immobilization increased all these activities in the plasma. AST-ALT ratio was also increased in these animals. Electrophoretic analysis of CK isoenzymes showed the appearance of CK-MB. These results indicate that the heart was injured in immobilized mice. Analysis of LDH isoenzymes and measurement of alpha-hydroxybutyrate dehydrogenase (HBDH) activity suggests that other tissues, in addition to the heart, contribute to the increase in plasma LDH activity. Restraint in small cylinders increased plasma LDH, CK, AST, and ALT activities, but to lower levels than in tape immobilization. Because the decrease in liver glycogen and the increase in plasma epidermal growth factor (EGF) were also smaller in restraint than in the tape-immobilization model of emotional stress, we conclude that the former is a less intense stressor than the latter. Cold exposure during the restraint period altered the early responses to stress (it enhanced liver glycogen decrease, but abolished the increase in plasma EGF concentration). Cold exposure during restraint enhanced heart injury, as revealed by the greater increase in CK and AST activities. Intermale confrontation progressively decreased liver glycogen content. Plasma EGF concentration increased (to near 100 nM from a resting value of 0.1 nM) until 60 minutes, and decreased thereafter. Confrontation also affected cellular integrity in some tissues, as indicated by the rise in plasma LDH activity. However, in this type of stress, the heart appeared to be specifically protected because there was no increase in plasma CK activity, and both AST and ALT increased, but the AST-ALT ratio remained constant. Habituation to restraint (1 h/d, 4 days) made mice resistant to restraint-induced tissue injury as indicated by the lack of an increase in plasma LDH, CK, AST, or ALT activities. Similar general protection against homotypic stress-induced injury was observed in mice habituated to intermale confrontation.     

Effects of ATP on the stability of enzymes against heat treatment in 6-aminonicotinamide treated quail

The stabilities of liver and pectoral muscle enzymes in 6-aminonicotinamide (6-AN) treated quail against heat treatment in the presence and absence of added ATP were investigated. Only ATP level in the brain and pectoral muscle of 6-AN treated group was significantly reduced compared to the control group whereas ADP and AMP levels were not affected. In the thermal stability (55 degrees C) of liver enzymes, the activity of acetylcholinesterase (AChE) was not affected whereas the activities of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase (LDH) were significantly lowered (P<0.01). The addition of 1mM ATP to liver enzyme extracts of 6-AN group afforded 4- and 1.7-fold more protection for GAPDH and LDH, respectively (P<0.01). In liver, LDH appeared to be more protected by ATP than GAPDH. In muscle, however, GAPDH and AChE activity were significantly affected but not LDH. The addition of 1mM ATP to muscle enzyme extracts of 6-AN group afforded 1.7-fold more protection for GAPDH (P<0.01) but rather inactivated AChE. A marked reduction in ATP levels in muscle did not affect specifically muscle enzyme activities only since liver enzyme activities were also affected to the same degree as muscle.     

Plasma enzyme levels in the anaesthetised dog during drainage of thoracic duct lymph.

The effect of continuous removal of thoracic duct lymph on plasma activities of creatine phosphokinase (PCK), glutamic-oxaloacetic transaminase (PAST); and lactic dehydrogenase (PLDH), uas examined in pentobarbital-anaesthetised dogs over a 5.5-hour period. PCK and PAST declined relative to levels in control dogs while PLDH was unaltered. Lymph/plasma (L/P) ratios for AST and CPK were greater, and for LDH less, than the L/P ratio for total protein. It was concluded that PCK, and to some extent PAST, are normally maintained by introduction of enzyme, escaping from the intracellular compartment, into the circulating blood via the lymphatic system. PLDH and PAST appear to be maintained principally by introduction of enzyme directly from the intracellular to the plasma compartment.     

Changes in plasma levels of lysosomal and non lysosomal enzymes during hemorrhagic hypotension.

In a study of 4-hr hemorrhagic hypotension in dogs, the plasma levels of the lysosomal enzymes, cathepsin (CATH) and acid phosphatase (AP) showed early and progressive increases in activity. The plasma levels of the intestinal fraction of alkaline phosphatase (IAkP) and aspartate aminotransferase (AAT) were increased after 2 hr of hypotension and the liver specific enzyme, ornithine carbamyltransferase (OCT), and creatine phosphokinase (CPK), after 3 hr. All of the enzymes showed large increases after 4 hr of hypotension. The plasma levels of CATH showed the earliest and largest relative increase indicating that with the shock model used, this enzyme was the most sensitive indicator of shock severity. The increase in plasma enzyme levels was probably the result of tissue damage in the splanchnic region but the elevation of plasma CPK, a muscle specific enzyme, indicates some muscle cell damage as well. While the increase in the plasma enzyme activity is probably due, in large part, to cellular damage, it is likely that a decreased enzyme removal rate--resulting from a hypofunctional RES--also contributes to the elevated plasma enzyme levels during hemorrhagic hypotension.     

Effect of spinal cord stimulation on the metabolism of developing latissimus dorsii muscles in chick embryo

Influence of chronic spinal cord stimulation upon some characteristic enzyme activities of energy metabolism was investigated in slow anterior (ALD) and fast posterior (PLD) latissimus dorsii muscles of the chick embryo. During embryonic life, oxidative metabolism (as evaluated by the activity of malate dehydrogenase (MDH] represents the main energetic pathway in both slow and fast muscles. At the end of embryonic life, an increase in anaerobic (as evaluated by the activity of lactate dehydrogenase (LDH] and creatine phosphokinase (CPK) activities occurs in PLD muscle. Chronic spinal cord stimulation at a low frequency was performed from the 10th day to the 16th day of embryonic development. In ALD, the enzyme activities were unaffected, while in PLD a concomitant decrease in LDH and CPK activities was observed.     

Effect of isoproterenol (ISO) on rat heart,liver, kidney,and muscle tissue levels of zinc,copper, and magnesium

X-ray fluorescence and atomic absorption spectrometry were used to measure the concentrations of zinc, copper, and magnesium in the heart, liver, skeletal muscle, and kidney following isoproterenol-induced myocardial necrosis in male albino rats. Serum activities of lactic dehydrogenase (LDH), creatine phosphokinase (CPK), and glutamic oxaloacetic transaminase (SGOT) were also measured. There was depletion of myocardial zinc, copper, and magnesium on d 1, followed by an uptake of all these elements on d 2. The liver showed a significant uptake of magnesium, along with depletion of copper. There was no change in the kidney and skeletal muscle concentrations of these elements. Possible explanations for the observed changes and their therapeutic significance are presented.     

Post-treatment with N-acetylcysteine ameliorates endotoxin shock-induced organ damage in conscious rats

N-acetylcysteine (NAC) is an antioxidant and cytoprotective agent with scavenging action against reactive oxygen species and inhibitory effects on pro-inflammatory cytokines. In a previous study, we found that pretreatment with NAC attenuated organ dysfunction and damage, reduced the production of free radicals, tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) following endotoxemia elicited by administration of lipopolysaccharide (LPS). In the present study, we tested the effects of post-treatment with NAC on the sepsis-induced change. Post-treatment imitates clinical therapeutic regimen with administration of drug after endotoxemia. Endotoxin shock was induced by intravenous injection of Klebsiella pneumoniae LPS (10 mg/kg) in conscious rats. Mean arterial pressure (MAP) and heart rate (HR) were continuously monitored for 48 h after LPS administration. NAC was given 20 min after LPS. Measurements of biochemical substances were taken to reflect organ functions. Biochemical factors included blood urea nitrogen (BUN), creatinine (Cre), lactate dehydrogenase (LDH), creatine phosphokinase (CPK), aspartate transferase (GOT), alanine transferase (GPT), TNF-alpha, interleukin-6 (IL-6), and interleukin-10 (IL-10). LPS significantly increased blood BUN, Cre, LDH, CPK, GOT, GPT, TNF-alpha, IL-6, IL-10 levels and HR, and decreased MAP. Post-treatment with NAC diminished the decrease in MAP, increased the HR, and decreased the markers of organ injury (BUN, Cre, LDH, CPK, GOT, GPT) and inflammatory biomarkers (TNF-alpha, IL-6, IL-10) after LPS. We conclude that post-treatment with NAC suppresses the release of plasma TNF-alpha, IL-6, and IL-10 in endotoxin shock, and decreases the markers of organ injury. These beneficial effects protect against LPS-induced kidney, heart and liver damage in conscious rats. The beneficial effects may suggest a potential chemopreventive effect of this compound after sepsis.     

Rapid release of tissue enzymes into blood after blast exposure: potential use as biological dosimeters

Explosive blast results in multiple organ injury and polytrauma, the intensity of which varies with the nature of the exposure, orientation, environment and individual resilience. Blast overpressure alone may not precisely indicate the level of body or brain injury after blast exposure. Assessment of the extent of body injury after blast exposure is important, since polytrauma and systemic factors significantly contribute to blast-induced traumatic brain injury. We evaluated the activity of plasma enzymes including aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and creatine kinase (CK) at different time points after blast exposure using a mouse model of single and repeated blast exposures to assess the severity of injury. Our data show that activities of all the enzymes in the plasma were significantly increased as early as 1 h after blast exposure. The elevated enzyme activity remained up to 6 h in an overpressure dose-dependent manner and returned close to normal levels at 24 h. Head-only blast exposure with body protection showed no increase in the enzyme activities suggesting that brain injury alone does not contribute to the systemic increase. In contrast to plasma increase, AST, ALT and LDH activity in the liver and CK in the skeletal muscle showed drastic decrease at 6 h after blast exposures. Histopathology showed mild necrosis at 6 h and severe necrosis at 24 h after blast exposures in liver and no changes in the skeletal muscle suggesting that the enzyme release from the tissue to plasma is probably triggered by transient cell membrane disruption from shockwave and not due to necrosis. Overpressure dependent transient release of tissue enzymes and elevation in the plasma after blast exposure suggest that elevated enzyme activities in the blood can be potentially used as a biological dosimeter to assess the severity of blast injury.     

Stobadine and heart mitochondria

Previous work has shown, that stobadine-hydrochloride (-)cis-2,8-dimethyl-2,3,4,4a,5,9b-hexahydro-14-pyrido(4,3b) indole administered in a single dose 2 mg/kg of body weight reduces cardiotoxic effect of isoproterenol (1 mg/kg) as shown by lowered serum enzyme activities of AST, CPK, LDH and ALT. We studied the effect of stobadine in vivo on respiration, the level of ATP, malondialdehyde (MDA) and superoxiddismutase (SOD) in heart mitochondria. Serum enzyme activities of AST, CPK and LDH after stobadine application were significantly decreased. In mitochondria, respiration and activity of SOD were inhibited, level of MDA was increased and level of ATP was unchanged. The cardioprotective effect of stobadine is not linked to preservation of mitochondrial function. This effect is probably more complex and mediated on the level of the whole organism.     

Serum and organ creatine phosphokinase alterations in exercise.

Rats that swam for 3 h showed a 6-fold increase in serum creatine phosphokinase (SCPK) activity which declined to control values within 7 h after swimming. Of the excess SCPK, 77% was BB isoenzyme; the remainder was mainly MM with traces of MB. Kidney, liver, brain and lung contain mainly BB (50-80%) and only a trace of MB (0-7%). Heart CPK was composed of little BB (8%) and more MB (28%) and MM (64%). Skeletal muscle CPK was almost entirely MM. CPK activity is highest in skeletal muscle, intermediate in heart and brain and lowest in kidney, liver and lung. It is suggested that skeletal muscle and heart are not involved in CPK release in swimming, and kidney, liver and brain may be sites of release.     

Enzyme activities in plasma, liver and kidney of black ducks and mallards

Activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine phosphokinase (CPK), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) were measured in plasma, liver, and kidney, and gamma-glutamyl transferase (GGT) was measured in liver and kidney of black ducks (Anas rubripes). Activities of ALT, AST, GGT, and ornithine carbamyl transferase (OCT) were assayed in plasma, liver, and kidney of game-farm mallards (Anas platyrhynchos). Appreciable OCT and AST activity occurred in both liver and kidney. Activities of ALT, CPK, ALP and GGT were higher in kidney, while LDH was higher in liver, GGT was detected in plasma from one of four mallards.     

Zinc dyshomeostasis in rats with aldosteronism. Response to spironolactone

Zinc is a structural constituent of many proteins, including Cu/Zn superoxide dismutase (SOD), an endogenous antioxidant enzyme. Hypozincemia has been found in patients hospitalized with congestive heart failure, where neurohormonal activation, including the renin-angiotensin-aldosterone system (RAAS), is expected and oxidative stress is present. This study was undertaken to elucidate potential pathophysiological mechanisms involved in Zn dyshomeostasis in aldosteronism. In rats receiving aldosterone/salt treatment (ALDOST) alone for 1 and 4 wk or in combination with spironolactone (Spiro), an ALDO receptor antagonist, we monitored 24-h urinary and fecal Zn excretion and tissue Zn levels in heart, liver, and skeletal muscle, together with tissue metallothionein (MT)-I, a Zn(2+)-binding protein, and Cu/Zn-SOD activities in plasma and tissues. When compared with unoperated, untreated, age-/sex-matched controls, urinary and, in particular, fecal Zn losses were markedly increased (P < 0.05) at days 7 and 28 of ALDOST, leading to hypozincemia and a fall (P < 0.05) in plasma Cu/Zn-SOD activity. Microscopic scars and perivascular fibrosis of intramural coronary arteries first appeared in the right and left ventricles at week 4 of ALDOST and were accompanied by increased (P < 0.05) tissue Zn, MT-I, and Cu/Zn-SOD activity, which were not found in uninjured liver or skeletal muscle. Spiro cotreatment prevented cardiac injury and Zn redistribution to the heart. Thus increased urinary and fecal Zn losses, together with their preferential translocation to sites of cardiac injury, where MT-I overexpression and increased Cu/Zn-SOD activity appeared, contribute to Zn dyshomeostasis in rats with aldosteronism, which were each prevented by Spiro. These findings may shed light on Zn dyshomeostasis found in patients with decompensated heart failure.     

Electromuscular Incapacitation Current Induced Neuromuscular Tissue Injury

Electrical stun devices (ESDs) serve a basic role in law enforcement and provide an alternative to lethal options for target control by causing electromuscular incapacitation (EMI). A fundamental concern is the adverse health consequences associated with their use. The capability of EMI electric field pulses to disrupt skeletal muscle cells (i.e. rhabdomyolysis) was investigated over the operational range commonly used in commercial EMI devices. Functional and structural alteration and recovery of muscle and nerve tissue were assessed. In an anesthetized swine model, the left thigh was exposed to 2 min of electrical pulses, using a commercially available ESD or a custom-made EMI signal power amplifier. Serum creatinine phosphokinase (CPK), troponin, aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) levels were monitored intermittently for 6 h post-EMI exposure. A standard external cardiac defibrillator served as a positive control. Muscle and nerve tissue histology adjacent to the EMI contacts were examined. Post-EMI shock skeletal muscle function was evaluated by analyzing the compound muscle action potentials (CMAPs) of the rectus femoris muscle. Maximal energy cardiac defibrillator pulses resulted in rhabdomyolysis and marked elevation of CPK, LDH, and AST 6 h post-shock. EMI field pulses resulted in the animals developing transient acidosis. CMAP amplitudes decreased approximately 50% after EMI and recovered to near-normal levels within 6 h. Within 6 h post-EMI exposure, blood CPK was mildly increased, LDH was normal, and no arrhythmia was observed. Minimal rhabdomyolysis was produced by the EMI pulses. These results suggest that EMI exposure is unlikely to cause extremity rhabdomyolysis in normal individuals. Bioelectromagnetics. © 2020 Bioelectromagnetics Society     

Plasma ceruloplasmin Evidence for its presence in and uptake by heart and other organs of the rat

Evidence for the presence of the plasma protein, ceruloplasmin, in heart and other tissues of the rat was sought using various techniques. With p-phenylenediamine, ceruloplasmin-like oxidase activity was detected in heart postmitochondrial and 100 000 × g supernatants in amounts far exceeding those that could be accounted for by residual blood. Much lower levels were detected in kidney, brain and liver. Oxidase activity of heart purified on DEAE-cellulose in the same way as rat plasma ceruloplasmin and behaved identically also in disc gel electrophoresis. The presence of ceruloplasmin in heart extracts was confirmed immunologically by Ouchterlony diffusion, using rabbit antibody raised against pure rat ceruloplasmin. When pure [³H]leucin-labeled ceruloplasmin was infused intravenously into a copper-deficient rat, radioactivity was concentrated in the heart and brain within 2 h; radioactive counts per g attained 11 and 3 times those of plasma in the two organs, respectively. A lesser concentration occurred in the liver. The results suggest that circulating ceruloplasmin (made by the liver) finds its way into the cells of some organs, especially the heart, a phenomenon which may be related to the function of ceruloplasmin to provide copper to the cytochrome oxidase of various tissues.     

Oxidative damage and antioxidant enzyme activities in experimental hypothyroidism

Free radicals are now well known to damage cellular components. To investigate whether age and thyroid level affect peroxidation speed, we examined the levels of malondialdehyde and antioxidant enzyme activities in different age groups of hypothyroid rats. Hypothyroidism was induced in 30- and 60-day-old Wistar Albino rats by the i.p. administration of propylthiouracil (10 mg kg(-1) body weight) for 15 days. While malondialdehyde levels of 30- or 60-day-old hypothyroid rats were increased in liver, they were decreased in the tissues of the heart and thyroid. While glucose-6-phosphate dehydrogenase activity levels did not change in heart, brain and liver tissues of 30-day-old rats, they increased in brain and heart tissues of 60-day-old experimental groups, but decreased in the liver. Catalase activities decreased in the liver and heart of rats with hypothyroidism, but increased in erythrocytes. In control groups while malondialdehyde levels increased in brain, heart and thymus with regard to age, they decreased in plasma. Glucose-6-phosphate dehydrogenase and catalase activities were not affected by age in tissues of the thymus, thyroid and brain, but they were decreased in the heart tissue. The changes in the levels of lipid peroxidation and antioxidant enzyme activities which were determined in different tissues of hypothyroid rats indicate a cause for functional disorder of these tissues. Moreover, there may be changes depending on age at lipid peroxidation and antioxidant enzyme activity levels.     

Metabolic indicators in the skeletal muscles of harbor seals (Phoca vitulina)

The goal of this study was to determine the distribution of citrate synthase (CS), beta-hydroxyacyl coenzyme A dehydrogenase (HOAD), and lactate dehydrogenase (LDH) activities and myoglobin (Mb) concentration in the locomotor muscles (epaxial muscles) and heart of harbor seals. The entire epaxial musculature, which produces most of the power for submerged swimming, was removed and weighed, and three transverse sections (cranial, middle, and caudal) were taken along the muscle bundle. Multiple samples were taken along points on a circular grid using a 6-mm biopsy. A single sample was taken from the left ventricle of the heart. Muscle groups of similar function were taken from three dogs as a control. Mean values were calculated for four roughly equal quadrants in each transverse section of the epaxial muscles. There were no significant differences among the quadrants within any of the transverse sections for the three enzymes or Mb. However, there were significant differences in the mean enzyme activities and Mb concentrations along the length of the muscle. The middle and caudal sections had significantly higher mean levels of CS, LDH, and Mb than the cranial section, which may be correlated with power production during swimming. The enzyme ratios CS/HOAD and LDH/CS exhibited no variation within transverse sections or along the length of the epaxial muscles. Relative to the dog, the epaxial muscles and heart of the harbor seal had higher HOAD levels and lower CS/HOAD, which, taken together, indicate an increased capacity for aerobic lipid metabolism during diving.     

Flight muscle enzyme activities do not differ between pelagic and near-shore foraging seabird species

Common terns (Sterna hirundo), sooty terns (S. fuscata) and brown noddies (Anous stolidus) are phylogenetically related seabirds that differ in field activity levels and daily energy expenditure. To test whether muscle metabolic capacities co-evolve with activity levels and energy expenditure, we collected pectoral muscle biopsies from members of each species, and measured the activities of key enzymes in oxidative metabolism (citrate synthase, CS), anaerobic metabolism (lactate dehydrogenase, LDH), glycolysis (pyruvate kinase, PK), fatty acid oxidation (3-hydroxyacyl CoA dehydrogenase) and phosphocreatine hydrolysis (creatine phosphokinase, CPK). We hypothesized that temperate-breeding common terns would have higher enzyme activities than the two tropical species (sooty terns and brown noddies); consistent with the higher activity level of common terns. There were no differences in enzyme activities among adults of the three species. Common tern chicks within 2-3 days of flight had two-fold higher pyruvate kinase activity than adults, suggesting an increased glycolytic capacity in the chicks. Given the lack of difference among species at the enzymatic level, our results support the notion that behavior and whole organism performance can evolve considerably before there are detectable changes in underlying lower-level physiological/biochemical traits.