Taurine requirement in primates.
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Animals↗
Biomedical subjects
K C Hayes
Publications and source records attributed to K C Hayes.
Plasma and hepatic apoE isoproteins of nonhuman primates. Differences in apoE among humans, apes, and New and Old World monkeys.
We have used two-dimensional polyacrylamide gel electrophoresis (PAGE) to study the plasma and hepatic apoE isoproteins of nonhuman primates and have compared them with their human counterparts. We have found that apoE obtained from fresh monkey or ape plasma, as well as nascent apoE synthesized by perfused monkey livers, is composed of several isoproteins that resemble the homozygous (beta) apoE phenotype observed in humans. The nonhuman primate plasma apoE pattern of 90 animals from nine different species consisted of a major isoprotein designated apoE3 and a few minor isoproteins. A group of acidic apoE isoproteins is eliminated after treatment with C. perfringens neuraminidase and has been designated sialo apoE (apoEs). Nonhuman primate liver apoE isoproteins comigrate with their plasma apoE isoprotein counterparts on two-dimensional PAGE, but hepatic apoE is enriched in sialo apoE isoproteins when compared to plasma apoE. The apparent molecular weight of asialo and sialo apoE obtained from Old World monkeys and apes is identical to the molecular weight of the corresponding human isoproteins (E3 = 38K, Es = 38.5-39.5K). However, the apparent molecular weight of apoE isoproteins obtained from New World monkeys is increased by approximately 0.5K (E3 = 38.5K, Es = 39.0-40.0K) as compared to the molecular weight of human and Old World monkey and ape isoproteins. The isoelectric points of apoE3 obtained from Old World monkeys, New World monkeys, chimpanzees, and gibbons are 5.74, 5.76, 5.95, and 5.89, respectively. The entire New or Old World monkey, chimpanzee, and gibbon apoE pattern is shifted by approximately -2.0, -0.5, and -1.0 charges, respectively, relative to the pattern of the corresponding human E3/3 phenotype. The molecular weight difference in apoE observed among New and Old World monkeys, as well as the molecular weight and/or charge differences observed among monkey, ape, and human apoE are consistent with structural changes in the apoE gene which have occurred following the divergence of the different species. The observation of only the homozygous apoE phenotypes in all animals studied suggests that the common apoE genetic polymorphism recently described in humans may not be present in nonhuman primates.
Animals↗
Knee joint effusion and quadriceps reflex inhibition in man.
This study was designed to elucidate the role of effusion in producing the reflex inhibition, and subsequent atrophy, of quadriceps musculature following knee trauma. In particular, consideration was given to determining the extent, threshold and linearity of inhibition of the motoneuron pool induced by experimental introduction of small increments of 0.9% physiological saline (up to 60ml) into the joint space of the knee in ten healthy subjects. Inhibition of the quadriceps muscle motoneuron pool was indirectly assessed through recording Hoffmann (H) reflexes evoked from vastus medialis, lateralis and rectus femoris. All ten subjects showed a significant (p less than 0.05) reduction in H-reflex amplitude following the introduction of saline: vastus medialis reduced to 55.7 +/- 4.3% of its control 0ml value, rectus femoris to 69.1 +/- 6.1% and vastus lateralis to 65.3 +/- 4.0%. Post hoc analyses of the H-reflex amplitudes at each increment of simulated effusion revealed the threshold for reflex inhibition of the vastus medialis to be between 20 and 30ml of saline and for rectus femoris and vastus lateralis to be between 50 and 60ml. These procedures were repeated on eight subjects following an injection of the anesthetic lidocaine (1%) to the intra-articular space of their knee joints but there was no significant reduction in H-reflex amplitude. Linear relationships were found to adequately describe the relationships between the volume of effusion and intra-articular pressure; and volume of effusion and reduction in H-reflex amplitude.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Human servo responses to load disturbances in fatigued muscle.
Short and long latency EMG responses to muscle stretch and shortening were investigated in the triceps brachii muscle of 16 human subjects during a fatiguing isometric contraction. Increased amplitude reflex responses to stretch, and accentuated reductions in EMG in response to shortening, were evident as fatigue progressed in the majority of subjects. These changes indicate internal compensatory adjustments in the nervous system offsetting the deleterious mechanical effects of muscular fatigue.
Adult↗
Altered lipoprotein metabolism in spontaneous vitamin E deficiency of owl monkeys.
Certain owl monkeys (AOT) develop spontaneous hemolytic anemia that responds to vitamin E. The anemia is associated with red blood cell lipid peroxidation and altered red blood cell membrane lipid composition. To investigate these changes, plasma lipid and lipoprotein profiles were characterized in anemic, anemia-susceptible, and anemia-resistant AOT. The plasma vitamin E and vitamin A concentrations were assessed as an index of fat absorption and the effect of corn oil supplementation and vitamin E-selenium injection were measured. Anemia-susceptible AOT had depressed plasma levels of vitamin E and A and an altered lipoprotein metabolism characterized by elevated ratios of low/high density lipoprotein cholesterol and free to esterified cholesterol in these lipoproteins. Vitamin E-selenium injection in anemia-susceptible AOT increased the plasma vitamin E, and vitamin E and corn oil supplements reduced the high density lipoprotein free to esterified cholesterol ratio. The data suggest that the AOT suffer from fat malabsorption and that the consequences (including tocopherol deficiency) result in altered cholesterol metabolism.
Anemia, Hemolytic↗
Characteristics of the triceps brachii tendon reflex in man.
The quantitative characteristics of the triceps brachii tendon reflex have been investigated in nine healthy adults. Particular consideration was given to the normal latency and amplitude values in response to a standardized tendon percussion. The effects of Jendrassik maneuver, head position (tonic neck reflex influences) and elbow joint angle were also evaluated. The latency of the triceps brachii reflex (mean = 11.2 msec) under normal conditions was found to be substantially shorter than previously reported values for the monosynaptic response. These differences are apparently attributable to the different methods that have been used to elicit the reflex. The present results are shown to be quite compatible with the known conduction velocity properties of the radial nerve. The mean amplitude of the reflex (means = 1.6 mV) was shown to be significantly (p less than 0.05) influenced by head position and Jendrassik maneuver. The magnitude of these effects are interpreted with respect to the proportion of the motoneuron pool activated by Ia inputs. Their neurophysiological basis and clinical usefulness are also discussed briefly.
Adult↗
Biliary lipids in New World monkeys: dietary cholesterol, fat, and species interactions.
The separate effects contributed by dietary cholesterol and dietary fat on several parameters of biliary lipid metabolism thought to be important in the genesis of cholesterol gallstones were examined in squirrel and cebus monkeys fed diets containing either corn or coconut oil from birth. Half the monkeys were also fed cholesterol. In gallstone-susceptible squirrel monkeys, corn oil tended to decrease the bile acid pool size and decrease the percentage of taurochenodeoxycholic acid. Dietary cholesterol effected major changes in gallbladder bile molar percent lipid composition with significantly increased cholesterol saturation indices that exceeded the metastable-labile limits. The supersaturated biles notwithstanding, none of the monkeys developed gallstones and only one had cholesterol crystals in its bile. By contrast, the gallstone-resistant cebus monkeys experienced less remarkable shifts in biliary lipid composition during dietary challenges of cholesterol and fat. The data are consistent with the hypothesis that neither a diminished bile acid pool size nor bile supersaturated with cholesterol are sufficient in themselves to result in gallstone formation in immature monkeys.
Animals↗
Biomechanics of postural control.
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Anthropometry↗
Hemolytic anemia of owl monkeys: red blood cell lipid alterations.
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Anemia, Hemolytic↗
Nutritional problems in cats: taurine deficiency and vitamin A excess.
Two nutritional problems of the cat are reviewed. One represents a deficiency of taurine, the other vitamin A toxicity. Taurine deficiency in cats is insidious because the progressive retinal degeneration induced may go unnoticed until the damage is advanced and irreversible. Both rods and cones undergo degeneration along with the underlying tapetum lucidum. The hyperreflective focal lesion is easily observed in the area centralis with an ophthalmoscope and has been previously identified as feline central retinal degeneration. This lesion is not reversed by taurine supplementation, even though the remaining retina may be saved from further degeneration. The cat requires dietary taurine, found in meat and fish, because it cannot synthesize enough to meet demands for bile acid conjugation and tissue metabolism, especially those of muscle and central nervous system. Vitamin A toxicity is not commonly observed in cats but may occur if cats are fed beef liver in which appreciable vitamin A is stored. Cats exhibit muscle soreness and hyperesthesia, especially along the neck and forelimbs where bony exostoses of cervical verterbrae and longbones are common. The diagnosis is readily made from radiographs. The response to removal of vitamin A from the diet is generally rapid and, unless the toxicity has been chronic in young kittens, recovery is generally satisfactory.
Animal Nutritional Physiological Phenomena↗
Erythrocyte characteristics in vitamin E-responsive anemia of the owl monkey (Aotus trivirgatus).
To characterize the vitamin E-responsive anemia occurring in owl monkeys (Aotus trivirgatus), osmotic fragility, and H2O2-induced and time-dependent hemolysis, as well as RBC lipid peroxidation, were compared in anemic and nonanemic owl monkeys. Whereas vitamin E serves as a lipid-soluble antioxidant, the glutathione peroxidase system functions in the water-soluble phase of the cell. Thus, activity of glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase, as well as reduced glutathione concentrations in owl monkeys' RBC, were compared with those of rhesus macaques and cebus and squirrel monkeys fed the same diet and maintained under the same management scheme. Osmotic fragility did not differ between anemic and nonanemic owl monkeys. The H2O2-induced and time-dependent hemolysis was approximately 10-fold greater among anemia owl monkeys than among their nonanemic counterparts, and lipid peroxidation values tended to be higher in the anemic monkeys. Owl monkeys, as a species and independent of anemia, exhibited higher RBC peroxidation than did 2 other New World species, cebus and squirrel monkeys. The glutathione peroxidase system was not depressed in owl monkey RBC. The only observed difference in this system was in the glucose-6-phosphate dehydrogenase activity, which was 3- to 6-fold higher in the owl monkey than in the other species, indicating an increased activity of the peroxidase system. Thus, a defect in the glutathione peroxidase system could not be identified.
Anemia↗
Taurine and tapetum structure.
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Animals↗
Taurine deficiency: a rationale for taurine depletion.
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Amino Acids, Sulfur↗
Histochemical localization of zinc in the feline tapetum. Effect of taurine depletion.
High resolution electron microscopy of ultrathin sections confirms the presence of a membrane surrounding the tapetal rods in the cat. Cats depleted of taurine exhibit disruption and disorganization of this membrane, probably the first stage of more severe tapetal degeneration. Histochemical localization of zinc shows it to be present on the periphery of the tapetal rods. The amount of zinc present on the periphery of the tapetal rods of taurine depleted cats was greatly reduced. Taurine in feline tapetum, confirmed by autoradiography and direct measurement, was also greatly reduced in taurine-depleted cats. We conclude that both taurine and zinc are localized on the periphery of the tapetal rods and that they contribute to the stability of the membrane. We have also confirmed earlier reports that the cat tapetal rods contain riboflavin and no detectable cysteine.
Animals↗
Bile lipid alterations in taurine-depleted monkeys.
Newborn cebus and cynomolgus monkeys, differing in their inherent taurine-glycine conjugation of bile acids, were fed taurine-free soy protein infant formula (Isomil) with or without added taurine (500 mg/kg dry diet). After 5 months, monkeys were anesthetized, their enterohepatic circulation interrupted, and their bile pool drained for 4.5 h. Bile acid conjugation, total bile acid pool size, biliary lipid composition, and theoretical maximal cholesterol solubility in bile were determined. Taurine depletion in cebus monkey, an obligate taurine conjugator (97%), did not reduce bile acid conjugation with taurine, or did it alter bile acid pool size, biliary lipid composition, or theoretical maximal cholesterol solubility in bile. Conversely, taurine depletion in cynomolgus, a species normally conjugating with some glycine (15 to 20%), significantly reduced conjugation of taurine with bile acids from 84 to 64%, essentially doubling that of glycine from 16 to 36%. Furthermore, theoretical maximal cholesterol solubility in cynomolgus bile improved significantly as a result of taurine depletion. This improvement was associated with increased percentage distribution of biliary phospholipid from 17 to 33%, in turn reflecting an increase in the taurochenodeoxycholate to taurocholate ratio from 0.7 to 2.9. Concomitant increase in biliary cholesterol concentration associated with increased glycine conjugation precluded any changes in the percent saturation of bile which remained constant at 130% for both dietary groups of cynomolgus. Taurochenodeoxycholate uniquely conserved taurine in the face of body taurine depletion. Taurine availability thus potentially has a substantial influence on bile acid characteristics and cholesterol solubility in a glycine conjugating primate.
Animals↗
Separation of the dietary fat and cholesterol influences on plasma lipoproteins of rhesus monkeys.
In order to isolate the effects of the type of dietary fat from those of dietary cholesterol on the circulating pool of cholesterol, plasma lipoproteins were characterized in juvenile rhesus monkeys fed semipurified diets containing 31% of calories as corn oil or coconut oil. Half the diets contained 300 mg of cholesterol per 1000 kcal. The fatty acids of cholesteryl esters and phospholipids varied significantly with dietary fat such that saturated and monounsaturated fatty acids replaced polyunsaturated fatty acids in low-density lipoproteins (LDL) and high density-lipoproteins of rhesus monkeys fed coconut oil. Dietary cholesterol alone induced small but significant increases in the cholesteryl ester: triglyceride ratio in both very low-density lipoproteins and LDL. Whereas neither saturated fat (coconut oil) nor cholesterol alone substantially altered the plasma cholesterol concentration or lipoprotein profile, together these dietary components interacted synergistically to produce a significant elevation in plasma cholesterol. This was due primarily to a significant rise in the cholesteryl ester fraction of LDL, disproportionate to any change in LDL protein concentration. The data are consistent with current hypotheses that relate parameters of LDL turnover and clearance to their macromolecular structure and physicochemical characteristics.
Animals↗
Nutritional evaluation in cotton-top tamarins (Saguinus oedipus).
Four cotton-top tamarins were fed a commercial biscuit diet and three others a commercial canned diet for 12 weeks. Thereafter, all seven were fed a purified diet for 12 weeks. General health, body weight, food intake, fecal output, serum biochemistry, blood count, and colonic histopathology were evaluated at various times during the experiments. The diets did not affect these parameters except the purified diet was associated with relatively reduced fecal output. Diarrhea and chronic colitis occurred independently of the diet in three tamarins in the course of the study.
Animals↗