Inhibition of the glycogen phosphorylase system during ochratoxicosis in chickens

Graded doses of ochratoxin A incorporated into the diet (0, 0.5, 1.0, 2.0, 4.0, and 8.0 micrograms/g) of broiler chickens significantly (P < 0.05) inhibited activity of protein kinase, the initiator enzyme of the glycogen phosphorylase system, in the livers at all dose levels. Only the highest dose, 8.0 micrograms/g, significantly reduced the total activity of phosphorylase kinase, which is activated by protein kinase. The total activity of phosphorylase, which is activated by phosphorylase kinase, was unaltered by ochratoxin A at any level. Additon of ochratoxin A to liver extracts control birds inhibited protein kinase but not phosphorylase kinase. When added to extracts of livers from control birds, cyclic adenosine 3',5'-monophosphate stimulated protein kinase but not phosphorylase kinase. The cyclic adenosine 3',5'-monophosphate had no effect when added to extracts from birds fed ochratoxin A. These results suggest that ochratoxin A affects primarily the cyclic adenosine 3',5'-monophosphate-dependent protein kinase which initiates the enzymatic cascade leading to glycogenolysis. Furthermore, these results conform an earlier assignment on morphological criteria of the glycogenosis of ochratoxicosis as a type X glycogen storage disease.     

Inhibition of the glycogen phosphorylase system during ochratoxicosis in chickens.

Graded doses of ochratoxin A incorporated into the diet (0, 0.5, 1.0, 2.0, 4.0, and 8.0 micrograms/g) of broiler chickens significantly (P < 0.05) inhibited activity of protein kinase, the initiator enzyme of the glycogen phosphorylase system, in the livers at all dose levels. Only the highest dose, 8.0 micrograms/g, significantly reduced the total activity of phosphorylase kinase, which is activated by protein kinase. The total activity of phosphorylase, which is activated by phosphorylase kinase, was unaltered by ochratoxin A at any level. Additon of ochratoxin A to liver extracts control birds inhibited protein kinase but not phosphorylase kinase. When added to extracts of livers from control birds, cyclic adenosine 3',5'-monophosphate stimulated protein kinase but not phosphorylase kinase. The cyclic adenosine 3',5'-monophosphate had no effect when added to extracts from birds fed ochratoxin A. These results suggest that ochratoxin A affects primarily the cyclic adenosine 3',5'-monophosphate-dependent protein kinase which initiates the enzymatic cascade leading to glycogenolysis. Furthermore, these results conform an earlier assignment on morphological criteria of the glycogenosis of ochratoxicosis as a type X glycogen storage disease.     

Intestinl fragility during ochratoxicosis and aflatoxicosis in broiler chickens.

Graded concentrations of dietary ochratoxin (0, 0.5, 1.0, 2.0, 4.0, and 8.0 microgram/g) and aflatoxin (0, 0.625, 1.25, 2.5, 5.0, and 10.0 microgram/g) were fed to broiler chicks from hatching to 3 weeks of age. The breaking strength of the large intestines was decreased significantly (P < 0.05) by ochratoxin (2, 4, and 8 microgram/g), but not by aflatoxin. This fragility was accompanied by an increase in the weight of the large intestine relative to body weight of birds fed ochratoxin (4.0 and 8.0 microgram/g), whereas aflatoxin had no significant (P < 0.05) effect on this parameter. Lipid content of the large intestine was decreased significantly (P < 0.05) by aflatoxin (10.0 microgram/g) and increased by ochratoxin (8.0 microgram/g). Microscopic examination of cross sections of large intestines stained for collagen gave the impression of a great decrease in collagen content of birds fed ochratoxin, but not aflatoxin. The radial length of the collagenous longitudinal folds of the large intestine was decreased significantly (P < 0.05) by ochratoxin (2.0, 4.0, and 8.0 microgram/g). These observations, plus a field case characterized by intestinal ruptures causing carcass condemnations on the processing line and by the occurrence of aflatoxin and ochratoxin in the chicken feed, suggest a novel way in which mycotoxins cause economic loss to agriculture.     

Nephrotoxicity of Dietary Ochratoxin A in Broiler Chikens

Graded doses of pure ochratoxin A (0,0.5,1.0,2.0,4.0, and 8.0 mug of toxin per g of feed) were incorporated into a commercial diet which was fed to chicks from 1 day to 3 weeks of age, at which time the experiments were terminated. Growth was inhibited at 2.0 4,0, and 8.0 mug/g, whereas the kidneys were enlarged at doses of 1.0 mug/g and above. Renal function as measured by clearance of phenol red was decreased 15 and 31% by doses of 4.0 and 8.0 mug/g, respectively. Uric acid was increased 38 and 48% over the control values by doses of 4.0 and 8.0 mug/g, respectively. The plasma electrolytes Na, Cl,Ca, and K were measured; however, only K was significantly ( P smaller than 0.05) altered, showing a decrease at doses of 4.0 and 8.0 mug/g. The percentage dry weight of the kidneys decreased significantly at dose levels of 4.0 and 8.0 mug/g, indicative of edema. Histological examination of kidney sections gave the impression of edema and some tubular necrosis. Pathological changes were observed at all dose levels. These data demonstrate that ochratoxin A is a severe nephrotoxin in young broiler chickens.     

Impairment of phagocytosis by heterophils from chickens during ochratoxicosis.

The effect of graded concentrations of dietary ochratoxin A (0, O.5, 1.0, 2.0, 4.0, and 8.0 microgram/g of diet) on the in vitro phagocytic, locomotory, and bactericidal capacities of heterophils from broiler chickens was investigated. Both the percentage and the mean phagocytic activities were decreased significantly (P less than 0.05) at 4.0 and 8.0 microgram/g. Both directed and undirected locomotion of heterophila was impaired significantly at the same concentrations. A crossover experiment revealed that the reduced percentage of phagocytosis was associated with the heterophil itself and not with a serum factor such as complement. Heterophila from birds that consumed 4.0 microgram/g were not impaired in ability to kill engulfed bacteria.     

Evaluation of Bone Strength During Aflatoxicosis and Ochratoxicosis

Young chickens were fed graded levels of aflatoxin (0, 0.625, 1.25, 2.5, 5.0, and 10.0 μg/g of diet) or ochratoxin (0, 0.5, 1.0, 2.0, 4.0, and 8.0 μg/g of diet), and the breaking strength, displacement before failure, and diameter of their tibias were determined. Breaking strength was decreased at growth inhibitory levels of aflatoxin (2.5 μg/g) and ochratoxin (2 μg/g), whereas a reduction in diameter required higher levels (5.0 and 4.0 μg/g, respectively). Bones from birds with ochratoxicosis selected to have diameters equal to control bones had lower breaking strength. In an attempt to negate mathematically the effect of decreased diameter and bias in any selection process, stress at time of failure of the bones was calculated and found to be decreased by feeding aflatoxin but not ochratoxin. Total displacement of bones before breaking was increased significantly (P < 0.05) by both toxins at the highest levels administered, but this increase was primarily the result of an increase in displacement from the start of failure to complete failure. Increased displacement associated with both toxicoses was equal in bones selected to be of equal diameter or in bones from the same treatment but of different diameters. However, calculation of modulus of elasticity which is corrected for diameter revealed aflatoxin had no effect whereas ochratoxin tripled the effect. These data indicate that the material properties of bones can be altered during mycotoxicoses and suggest yet another way in which mycotoxins are detrimental to animal health.     

Isolation, purification, and antibiotic activity of o-methoxycinnamaldehyde from cinnamon.

o-Methoxycinnamaldehyde has been isolated and purified from powdered cinnamon. The compound inhibits the growth and toxin production of mycotoxin-producing fungi. The substance completely inhibited the growth of Aspergillus parasiticus and A. flavus at 100 microgram/ml and A. ochraceus and A. versicolor at 200 microgram/ml. It inhibited the production of aflatoxin B1 by over 90% at 6.25 microgram/ml, ochratoxin A at 25 microgram/ml, and sterigmatocystin at 50 microgram/ml. The substance also displayed a strong inhibitory effect on the growth of five dermatophytoses species, e.g., Microsporum canis (minimum inhibitory concentration, 3.12 to 6.25 microgram/ml). However, no antibacterial effect was observed at concentrations as high as 50 microgram/ml.     

Effect of estradiol on tissue glycogen metabolism in exercised oophorectomized rats

The effect of both physiological and pharmacological doses of estradiol on exercise performance and tissue glycogen utilization was determined in oophorectomized estradiol-replaced (ER) rats. Doses of beta-estradiol 3-benzoate (0.02, 0.04, 0.1, 0.2, 1, 2, 4, or 10 micrograms.0.1 ml of sunflower oil-1.100 g body wt-1) were injected 5 days/wk for 4 wk. Controls were sham injected (SI). After treatment, the animals were run to exhaustion on a motorized treadmill. ER animals receiving the 0.02-microgram dose ran significantly longer and completed more total work than the SI group. ER animals receiving doses of greater than or equal to 0.04 microgram ran longer and performed more work than the 0.02-microgram group. At exhaustion, myocardial glycogen content was significantly decreased in animals that were ER with less than or equal to 0.1 microgram, whereas those replaced with doses greater than 0.1 microgram utilized significantly less glycogen. With the 10-micrograms dose no significant decrease in heart glycogen content was observed at exhaustion. A submaximal 2-h run significantly reduced glycogen content in heart, red and white portions of the vastus lateralis, and the livers of SI animals. The latter effect was attenuated in skeletal muscle and liver, and there was no effect in the hearts of the ER animals receiving 2 micrograms. These data indicate that estradiol replacement in oophorectomized rats influenced myocardial glycogen utilization during exhaustive exercise and spared tissue glycogen during submaximal exercise. These glycogen sparing effects may have contributed to the significant improvements in exercise performance observed in this study.     

Effect of Kluyveromyces marxianus YIT 8292 crude cell wall fraction on serum lipids in normocholesterolemic and mildly hypercholesterolemic subjects

The hypocholesterolemic effects of Kluyveromyces marxianus YIT 8292 crude cell wall (KM-CW) were examined. In pilot studies, KM-CW tablets were administered to mildly hypercholesterolemic subjects at doses of 8.0, 4.0, 2.0, or 1.0 g/d for 4 weeks. Total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) decreased at doses above 2.0 and 4.0 g/d, respectively. Further, we examined the effect of intake of yogurt containing 3.0 or 4.0 g of KM-CW/d for 8 weeks in normal and hypercholesterolemic subjects in a double-blind placebo-controlled study. The intake of either of the KM-CW-containing yogurts was associated with significantly improved TC and LDL-C in hypercholesterolemic subjects, but had no effect on these levels in normal subjects. TC was significantly lower at week 8 in the hypercholesterolemic subjects who ingested yogurt containing 3.0 or 4.0 g of KM-CW than in those who consumed placebo yogurt. Intake of KM-CW might contribute to the prevention of hypercholesterolemia.     

Biochemical changes in the rat during experimentally induced acute ochratoxicosis

Biochemical changes in rat urine and tissues treated with five consecutive daily doses of ochratoxin A (10 mg/kg body weight) were studied. Urine volume and urinary proteins were moderately raised during the first few days of ochratoxin treatment, and were then highly elevated towards the end of the investigation. Urinary muramidase excretion was significantly raised (p less than 0.01) 24 h after the first insult with the toxin. The urinary output of alkaline and acid phosphatases, lactate dehydrogenase (LDH) and glutamate dehydrogenase (GDH) were all elevated but very much later, during the course of injections with ochratoxin A. Kidney alkaline and acid phosphatases, LDH and GDH were correspondingly reduced 7 days from the beginning of ochratoxin A administration. Liver LDH activity was reduced while serum LDH was raised. Liver glycogen level was significantly (p less than 0.0001) increased. Experimental evidence was presented to show that the initial point of interaction of ochratoxin A with the rat renal system may be at the first portion of the proximal convoluted tubular cell region.     

Thyroxine-induced changes of hepatic glucose-6-phosphatase activity and glycogen, protein, RNA and DNA contents in the rat

Thyroxine (T4) in a dose of 0.1 microgram per g body weight caused in the rat a significant increase in hepatic glucose-6-phosphatase activity, while a reduction of this enzyme activity was observed after 1 microgram of T4 per g. The hepatic glycogen content was found to be depleted and a marked elevation in protein, RNA and DNA contents were observed after both doses of T4.     

Effect of Kluyveromyces marxianus YIT 8292 Crude Cell Wall Fraction on Serum Lipids in Normocholesterolemic and Mildly Hypercholesterolemic Subjects

The hypocholesterolemic effects of Kluyveromyces marxianus YIT 8292 crude cell wall (KM-CW) were examined. In pilot studies, KM-CW tablets were administered to mildly hypercholesterolemic subjects at doses of 8.0, 4.0, 2.0, or 1.0 g/d for 4 weeks. Total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) decreased at doses above 2.0 and 4.0 g/d, respectively. Further, we examined the effect of intake of yogurt containing 3.0 or 4.0 g of KM-CW/d for 8 weeks in normal and hypercholesterolemic subjects in a double-blind placebo-controlled study. The intake of either of the KM-CW-containing yogurts was associated with significantly improved TC and LDL-C in hypercholesterolemic subjects, but had no effect on these levels in normal subjects. TC was significantly lower at week 8 in the hypercholesterolemic subjects who ingested yogurt containing 3.0 or 4.0 g of KM-CW than in those who consumed placebo yogurt. Intake of KM-CW might contribute to the prevention of hypercholesterolemia.     

Effect of corticosteroids on carbohydrate metabolism in Bufo melanostictus (Schneider)

A single injection of corticosterone (1 or 5 micrograms/50 g body weight) produced a significant elevation in plasma glucose, liver and muscle glycogen contents of B. melanostictus. Single but identical doses of aldosterone had no effect on plasma glucose concentration. Liver and muscle glycogen contents were however significantly augmented. Administration of 1 or 5 micrograms corticosterone and 1 microgram or 200 ng aldosterone/50 g body weight, for 15 days, caused no change in plasma glucose concentration. In all the groups receiving corticosterone or aldosterone for 15 days, liver and muscle glycogen contents significantly increased. The magnitude of increase in liver and muscle glycogen by aldosterone was marginally greater than that by corticosterone. The results suggest that both the corticosteroids may be gluconeogenic in B. melanostictus.     

Toxic effects of ochratoxin A and citrinin, alone and in combination, on chicken embryos.

The embryotoxic potential of ochratoxin A and citrinin was studied after administering, either subgerminally or intraamniotically, single mounting doses of the mycotoxins to chicken embryos on days 2, 3, and 4. The beginning of the embryotoxicity dose range was found to be between 0.01 to 0.05 microgram for ochratoxin A and 1 to 10 micrograms for citrinin. The maximum response to both mycotoxins occurred after administration on day 3. In addition to significant growth retardation of fetuses, exencephaly, microphthalmia, cleft beak, reduction deformities of the limbs, and abdominal wall and ventricular septal defects were encountered on day 8 of incubation. When 4 micrograms of citrinin was constantly added to ochratoxin A administered in the dose range of 0.03 to 0.5 microgram, a strictly additive effect was seen. It may be supposed that citrinin produced together with ochratoxin A in some strains of Penicillium viridicatum Westling does not potentiate the clear-cut embryotoxic action of the latter mycotoxin.     

Toxic effects of ochratoxin A and citrinin, alone and in combination, on chicken embryos

The embryotoxic potential of ochratoxin A and citrinin was studied after administering, either subgerminally or intraamniotically, single mounting doses of the mycotoxins to chicken embryos on days 2, 3, and 4. The beginning of the embryotoxicity dose range was found to be between 0.01 to 0.05 microgram for ochratoxin A and 1 to 10 micrograms for citrinin. The maximum response to both mycotoxins occurred after administration on day 3. In addition to significant growth retardation of fetuses, exencephaly, microphthalmia, cleft beak, reduction deformities of the limbs, and abdominal wall and ventricular septal defects were encountered on day 8 of incubation. When 4 micrograms of citrinin was constantly added to ochratoxin A administered in the dose range of 0.03 to 0.5 microgram, a strictly additive effect was seen. It may be supposed that citrinin produced together with ochratoxin A in some strains of Penicillium viridicatum Westling does not potentiate the clear-cut embryotoxic action of the latter mycotoxin.     

Metabolic response to short periods of starvation in hypo- and hyper-thyroid male rats.

1) Thyroidectomized rats were fed with a low iodine diet, injected daily with 0, 0.1, 1.8 or 25 microgram of L-thyroxine/100 g body wt., and compared with intact controls. 2) Plasma protein-bound iodine was decreased in the rats given the 0 and 0.1 microgram doses, unchanged in those given the 1.8 microgram doses, unchanged in those given the 1.8 microgram dose increased in those given the 25 microgram one. 3) The liver content of DNA-P, phospholipid-P, proteins and fatty acids was decreased in the rats that did not receive thyroxine, practically recuperated in those receiving 0.1 microgram and normal in those given 1.8 or 25 microgram of thyroxine. 4) 3 h of starvation produced a reduction in the liver content of total fatty acids that disappeared after 24 h. 5) When fed, liver glycogen concentration was low in the rats given 25 microgram of thyroxine. 6) With starvation, the fall in liver glycogen and blood glucose, and the rise in liver acetyl-CoA and citrate and blood glycerol concentrations were faster in the thyroidectomized rats that did not receive thyroxine than in the other groups. 7) The rise in plasma free fatty acid and blood ketone bodies concentrations were similar in all the groups, the greater level of the first parameter being observed after 6 h of starvation in the rats given 25 microgram of thyroxine and in the second one after 24 h in the rats given either 0.1, 1.8 or 25 microgram of thyroxine. 8) The rapid decrease in the availability of carbohydrate stores with starvation in the thyroidectomized rats could be responsible for their fast call for lipid utilization. The slower response to fasting in the hyperthyroid animals is probably a consequence of their reduced amount of endogenous substrates to be mobilized.     

玛咖提取物对运动耐力和脊神经元线粒体超微结构的影响

目的：探索玛咖提取物对运动耐力和脊神经元线粒体超微结构的影响。方法：50只Wistar大鼠随机分为5组。对照组：不进行游泳,灌胃等量蒸馏水;单纯游泳组：游泳,灌胃等量蒸馏水,玛咖提取物组（设4.0,5.3,8.0 g/kg 3个剂量组）：游泳,给予相应剂量的玛咖提取物。游泳大鼠在游泳池内循环水流自由游泳,连续游泳并给药15 d,第16天游泳耐力测试后无痛处死大鼠,用投射电子显微镜观察脊髓神经元线粒体超微结构,放免法测定肌肉肌糖元、检测肌肉中丙二醛（MDA）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）和游离钙水平。结果：与单纯游泳组比,沉下前游泳时间和游泳总时间分别延长了（%）19.83、60.28、77.55和55.34、73.91、94.47,差异均有统计学意义（P均<0.01）;沉下次数分别减少了（%）34.35、51.18、57.96,差异有统计学意义（P<0.01）;MDA和游离钙含量分别降低了（%）20.10、31.49、38.72,差异有统计学意义（P<0.01）和6.42、17.58、26.35;SOD、GSH-Px和肌糖原含量分别升高了（%）5.12、22.74、52.53、44.22、77.79、98.45,差异有统计学意义（P<0.01）和35.08、47.83、81.88,差异有统计学意义（P<0.01）;脊神经元线粒体的体密度（VD）、面密度（SD）和数密度（ND）分别减小了（%）7.79、18.18、31.17,16.95、27.34、43.31和13.51、23.19、43.15。结论：玛咖提取物具有保护脊髓神经元线粒体结构、抗氧化、增加肌糖原和提高运动能力等作用。     

Effect of thyroxine on hepatic glucose-6-phosphatase activity and glycogen content of toad (Bufo melanostictus) and Lata fish (Ophicephalus punctatus) at different stages of life

The effects of thyroxine (T4) on hepatic glucose-6-phosphatase activity and glycogen content in toad (Bufo melanostictus) and Lata fish (Ophicephalus punctatus) were studied in order to show the difference, if any in the enzyme activity and glycogen metabolism in their liver. Thyroxine injections (1 microgram/g) for five consecutive days caused a reduction in hepatic glucose-6-phosphatase activity and glycogen content in toads of immature, juvenile and adult stages. In contrast, Lata fish of different stages showed an enhancement of hepatic glucose-6-phosphatase activity after T4 treatment (1 microgram/g, 5 injections). The liver glycogen content in Lata fish of different age groups was found to be reduced after T4 injections, but not so much as in the toad.     

Thyroid hormone effects upon Na+K+ dependent adenosine triphosphatase activity of microsomal fraction of liver, muscle and brain of toad Bufo melanostictus

Na+K(+)-ATPase activity in the liver and muscle microsomal membranes have been determined by different doses (0.1, 0.25, 0.5, 1 and 2 micrograms/gm of body weight) of L-triiodothyronine and L-thyroxine in the toad, Bufo melanostictus. The minimum effective dose of T3 was 0.5 microgram/g in case of both liver and muscle to stimulate the enzyme activity and there was dose dependent rise between T3 at the doses of 0.5 and 1 microgram/g. T3 at the doses of 1 and 2 micrograms/g produced more or less the same level of activity. T4 showed an increased activity at 1 and 2 micrograms/g without any dose dependent fashion in the two organs. The doses 0.1 and 0.25 microgram/gm body weight of T3 and 0.1, 0.25 and 0.5 microgram/gm body weight of T4 remained ineffective to elicit any response in both organs. The grain showed no significant change in the enzyme activity at any of the applied doses of T3 and T4. Cycloheximide inhibited T3 induced rise in Na+K(+)-ATPase activity of liver and muscle. Treatment with propylthiouracil caused a significant fall in Na+K(+)-ATPase activity of liver and muscle and the normal value was restored in the two organs after three consecutive injections of T4 at the dose of 1 microgram/g.