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矩形波ポーラログラフ法によるグルタミン酸ナトリウム(M.S.G.),その他アミノ酸製品中の金属の分析結果を報告する.鉛については,前処理として,(1)ジチゾン抽出後,塩酸水溶液中に逆抽出する方法,(2)灰化法,(3)アミノ酸試料を直接支持塩溶液に溶かしてからポーラログラフ分析に供する各方法を比較検討した.亜鉛は,ジチゾン抽出により濃縮後,供試すればよい.カルシウムの定量は,Pribil法にしたがって,カルシウム量に当量な亜鉛のアンモニア錯体を遊離させ,そのボーラログラフ波を測定する.供試某社製品のM.S.G.中の金属含有量は,鉛が1.1～2.4ppm,亜鉛は2ppm以下,カルシウムは220～240ppmであった.

In a feed preference or acceptability trial 12 dairy calves offered a choice of a complete starter (18% crude protein and 20% ground suncured alfalfa) with 0 or 0.2% monosodium glutamate and weaned at three weeks, consumed more 0.2% glutamate starter each week and cumulatively from three to nine weeks of age than they did starter without glutamate. Differences in weekly starter consumption were significant (P In a growth trial 10 calves weaned at four weeks and fed 0.2% glutamate starter ate slightly, but not significantly (P>0.05), more feed weekly from birth to six weeks than 10 calves fed the same starter without glutamate. Slight differences in starter consumption from birth to four weeks were reflected in less weight loss the week after weaning by calves eating the glutamate ration than by those receiving the control starter. Differences in daily gain and feed efficiency from glutamate in the starter were negligible.

—Monosodium l-glutamate was injected subcutaneously into 4-day-old mice at a dose of 2 mg/g body wt. The infants were killed at sequential intervals after injection, the brains were frozen, and samples of the arcuate nucleus (NA), ventromedial hypothalamus (VMH) and lateral thalamus (LT) were micro-dissected from lyophilized sections for glutamate assay. Blood glutamate levels were also determined for comparison with brain levels of glutamate at corresponding post-injection intervals. Glutamate levels in the NA steadily increased to reach a peak value of 110.9 mmol/kg dry wt. at 3 h following injection, whereas the highest levels reached in the VMH or LT were about 41.7 mmol/kg dry wt. Return to control values of about 25 mmol/kg dry wt. occurred gradually over a period of 12–15 h in all three brain regions. Blood glutamate concentrations peaked rapidly, reaching a maximum of 40 mm within 15 min but returned precipitously to near-baseline values (below 1 mm) in the 1–3 h interval after injection. We discuss possible mechanisms to account for the transient marked accumulation of subcutaneously administered glutamate in the NA and how this might relate to the selective destruction of arcuate neurons which occurs simultaneously.

The signs and symptoms following the ingestion of monosodium glutamate (MSG) were found strikingly similar to those induced by acetylcholine (ACh). The effects of anticholinergic and cholinesterase (ChE) inhibitor support the hypothesis that Chinese restaurant syndrome is a “transient acetylcholinosis”. The pattern of plasma ChE activity in induced acetylcholinemia was strikingly similar to that following MSG ingestion.

The absorption and utilization of monosodium L-glutamate (MSG) have been studied in control and vitamin B6-deficient rats. When 1 mg of labeled or unlabeled MSG/gram of body weight was administered intraduo- denally, higher plasma glutamate but not 14Clevels were observed in the jugular and portal blood of deficient rats than controls. This appeared to be related to decreased tissue utilization and intestinal transaminatA­on of glutamate in de ficient animals. Vitamin B6 deficiency resulted in a delayed clearance from plasma of intravenously administered glutamate. Aspartate and alanine amino- transferases, the two major glutamate transaminases of the intestinal mucosa were measured in pre- and postweanling rats. The activity of these enzymes was low in rats under 21 days of age. They were not affected by pyridoxine adminis tration. Following weaning intestinal transaminase activity was markedly in creased by the feeding of diets with adequate vitamin B6 and further decreased by diets deficient in the vitamin. These studies point up the need in MSG toxicity studies to especially consider the age and state of vitamin B, nutriture of the animals used and the routes of MSG administration. J. Nutr. 102: 835-840

Two isomers of inosine-5′-thiophosphates, inosine-5′-phosphorothionate and 5′-deoxy-5′-thioinosine-5′-phosphorothioate, were synthesized by the direct phosphorylation of inosine with phosphorus thiochloride, and by the treatment of 5′-deoxy-5′-iodoinosine with trisodium phosphorothioate, respectively. The structure of the thiophosphate residues was identified by means of 31P NMR. The flavoring activities of these thiophosphates were measured as the synergistic strength with monosodium glutamate; it was found that the strength of each compound was lower than that of inosine-5′-phosphate.

Summary 1.In unanesthetized, normal dogs reversible ammonium intoxication was induced by intravenous infusion of (NH 4 ) 2 SO 4 at varying rates and by rapid intravenous injection of (NH 4 ) 2 CO 3 equivalent to 50 mg. (N) per kg. of body weight. 2.A rise in blood urea nitrogen follows the rise in blood ammonia nitrogen; pyruvic acid and glucose levels are elevated; but no significant change in blood α-ketoglutaric acid or in plasma glutamine occurs. 3.Disodium α-ketoglutarate, L-arginine hydrochloride, and monosodium glutamate, administered in appropriate doses before, during, and after the induction of intoxication, were ineffectual as protective agents. 4.The extent and duration of ammonium poisoning is shown to be independent of the pH of the blood, as affected by the doses of ammonium salts employed, but dependent upon the dose of ammonia nitrogen and the rate of administration. 5.From the measurements made on blood and plasma constituents there is no evidence to support the thesis that the symptoms of ammonium intoxication derive from the reductive amination of α-ketoglutaric acid, thus interrupting the continuity of the tricarboxylic acid cycle necessary to the metabolism of brain. 6.But it is pointed out that it is generally accepted that measurements of blood and plasma constituents do not necessarily reflect the concentration of these substances at any particular moment in the organism as a whole.

The potentiating effect of disodium 2-methyl mercapto-5'-inosinate (Mes-IMP) on gustatory responses to monosodium glutamate (MSG) was examined and compared with those of sodium 5'-inosinate (5'-IMP) and sodium 5'-guanylate (5'-GMP) by recording responses in the whole chorda tympani nerve and in single gustatory fibers in rats. Mes-IMP had a lower threshold for response than 5'-IMP. Addition of 0.0001% Mes-IMP to 0.3% MSG yielded significant enhancement in the response. The enhancement produced by Mes-IMP was nearly equal to that shown by 5'-IMP of an amount ten times greater. The enhancement was predominantly observed in fibers responsive to sucrose. The magnitude of the enhancement, produced by the addition of a fixed amount of Mes-IMP to MSG of varying concentrations, was greater at MSG concentrations below 0.03 M than at higher concentrations.

INTRODUCTION THE National Research Council (1960) recommends that a chick starting diet contain a minimum of 20 percent crude protein. It is common practice in the broiler industry to feed diets containing 22 percent or more protein in order to obtain maximal chick growth and feed efficiency. Assuming that the improved performance is due to additional amounts of critical essential amino acids, it seems logical that crystalline amino acids might be a more efficient means of supplying the most limiting amino acids in the diet. The use of crystalline amino acids in this manner may result, not only in diets containing a lower protein content than is presently recommended, but also in a diet that is more favorably balanced in essential amino acids. In addition, ingredients having a high energy content could partially replace intact protein sources which are relatively low in energy. Studies concerning the partial replacement of dietary…

Neonatal female and male rats of the Sprague-Dawley strain were injected subcutaneously with a daily dose of MSG (2.2–4.2 mg/g body wt.) beginning on the 2nd day of life. The rats were autopsied at 40

Extract: Therapy of identical twin males with the enzyme defect of the Lesch-Nyhan (L-N) syndrome was instituted at 12 hr of age with adenine, 10 mg/kg/24 hr, administered to one twin and folic acid, 15 mg/24 hr, to both. At 4 years of age both twins demonstrate delayed neurologic development and spasticity but are less severely affected than most other patients with this disorder. Administered in subsequent studies to two maternal cousins of the twins who had clinical features of the L-N syndrome and absence of erythrocyte hypoxanthine-guanine phosphoribosyltransferase activity were adenine, 10 mg/kg/24 hr, adenine, 40 mg/kg/24 hr, folic acid, and mono-sodium glutamate. Low dose adenine had a slight suppressive effect on glycine-l-14C incorporation into uric acid; high dose adenine had a strong suppressive effect in the second patient. We conclude that the adenine dose chosen for therapy was too low. 2,8-Dihydroxyadenine, a toxic breakdown product of adenine, was detected in the urine at both adenine dose levels. Folic acid and monosodium glutamate in these patients further stimulate accelerated glycine-l-14C incorporation into uric acid. In vitro transport studies, performed with inverted hamster jejunal preparations, suggest that adenine is largely converted to adenine monophosphate when exposed to the mucosal surface. This may limit the passage of orally administered adenine to the central nervous system in patients. Adenine and purine precursors affect the biochemical pathology of the L-N syndrome, in vivo and in vitro, but therapeutic use of adenine, 10 mg/kg/24 hr, and folic acid started on the 1st day of life did not prevent central nervous system dysfunction. Speculation: Variation in clinical presentation occurs in the Lesch-Nyhan syndrome. Although small therapeutic benefit may be ascribed to folic acid therapy in our patients, this is not established with certainty. A different approach may be required to prevent central nervous system disease in patients treated from birth.

Composite food products containing salt, monosodium glutamate, fat and a commercial beef, whale or yeast extract or chicken meat, or hydrolysed protein were examined, after extraction of the fat, by two-dimensional paper chromatography. Characteristic constituents of the extracts were resolved and the recognition of extracts is discussed. Commercial soup tablets and cubes from European countries were examined for whale extract by the method described: it was detected in all four chicken tablets, in two out of five cubes and in five out of twenty-three soup tablets.

SUMMARY— The synergistic phenomenon between the taste of monosodium glutamate (MSG) and disodium 5′-inosinate (IMP) [7.5 H2O] was studied and the relationship expressed as a mathematical model. The phenomenon could be measured quantitatively by fitting the proposed model to the results of the experiment. The concentration of MSG equivalent to the taste intensity of that given by the mixture of MSG and the ribonucleotide is represented by the following equation: y = u +γuv where y is the equivalent taste intensity of the mixture in terms of g/dl of MSG, u is equal to g/dl of MSG in the given mixture, v is equal to g/dl of sodium 5′-inosinate in the given mixture, and γ is a constant. The γ value for IMP was calculated from extensive sensory testing as 1.218 × 108.

SUMMARY— Intensity of glutamate-like and/or inosinate-like taste (umami in Japanese) of various flavor amino acids and flavor nucleotides was studied using sensory analysis and always found proportional to that of monosodium glutamate (MSG) and disodium 5′-inosinate (IMP), respectively. By application of this fact to a previously obtained equation expressing the relationship between the taste intensity of MSG-IMP mixture and that of MSG alone, the intensity of umami of the mixture of any flavor amino acids and nucleotides could be expressed as an elementary equation: y = u +γ uv, where u and v are the concentrations of amino acids and nucleotides in terms of the concentrations of MSG and IMP, respectively, in the mixture; y is the equivalent concentration of MSG alone; and γ is a positive constant. Interrelationships within each group of substances were additive.

Intraperitoneal or intragastric injection of monosodium l -glutamate (4 mg/g) to infant rats invariably caused an increase in brain glutamine, never in brain glutamate. The toxicity (convulsions) observed after these doses was not unique to l -glutamate; monosodium l -aspartate or d -glutamate gave similar symptoms. Equimolar doses of glycine did not cause convulstions but did elevate brain glutamine. These results suggest that the toxicity (convulsions) of monosodium l -glutamate is not due to ammonia but to the amino acid anions.

Experiments were conducted to investigate the possibility of laying hens utilizing sources of non-protein nitrogen for egg production. Sources of non-protein nitrogen were added to low protein diets composed of practical feed ingredients and to a semipurified diet composed mainly of glucose, starch, isolated soybean protein, and blood meal. Essential amino acid supplementation was used to achieve a better amino acid balance of the diets. When the nitrogen supplements were added to a diet containing 12.5% protein, and with levels of essential amino acids that approximated those recommended by the National Research Council, a graded response in egg production was obtained to two levels of supplemental urea. A similar supplementation with monosodium glutamate had no effect on egg production. A low level of diammonium citrate supplementation produced a small increase in egg production and a higher level depressed egg production and feed intake. When the level of protein in the basal diet was reduced to 11.5%, and diammonium phosphate was used as source of non-protein nitrogen there was a depression in egg production but not in feed intake or nitrogen retention. Diammonium phosphate had the same effect when supplemented to a semipurified diet that contained all essential amino acids at a level equal to or higher than that recommended by the National Research Council. When glycine was supplemented to the semipurified diet, an increase in egg production was obtained.

Although the relatively successful freeze-drying of streptomycin-dependent mutant Shigella vaccines has been reported previously, further studies have been undertaken for the following reasons: (1) To improve the survival rate of the vaccine strains after freeze-drying. (2) To see whether monosodium glutamate can be eliminated as a stabilizer as it is reported to produce pharmacological effects in man. Streptomycin-dependent Shigella flexneri 2a was chosen for this study as this strain among the vaccine strains is the most sensitive to the effects of freeze-drying. When 60–90 × 109 organisms are suspended in a solution containing 12.5% sucrose and 15% peptone, and freeze-dried, a survival of 90–100% has been obtained. This is a considerable improvement on previously published methods. During the study a number of streptomycin-independent revertants were isolated, but all were avirulent. There was no evidence that freezing or freeze-drying had any influence on the reversion rate.

IT HAS long been recognized that, for artificial insemination to have widespread application, methods for diluting and storing semen are necessary. Van Tienhoven et al. (1958) reported some success with milk as a diluent for turkey semen, although the fertility obtained with semen diluted in milk was lower than that of undiluted semen. Fairly good fertility (64%) was reported by Lake (1960) for chicken semen diluted in a synthetic diluent containing monosodium glutamate (1.92 mg.%) as the main component. By using carbon dioxide as a reversible inhibitor, Vandemark and Sharma (1957) developed a room temperature diluent called the “Illini Variable Temperature Diluent” (I.V.T.) for bovine semen. Polge et al. (1949) and Clark and Shaffner (1960) obtained 54 to 40% fertility, respectively, in their attempts to preserve chicken semen by freezing. Lack of information on a diluent containing carbon dioxide as a reversible inhibitor of metabolism for chicken and turkey semen,…

SUMMARY High inter-personal variability has been noted in the taste qualities people report for solutions of sodium benzoate. This study sought to determine whether such variability occurs with other substances and to assess the role of learning in development of the response. 24 S's replicated ratings of the intensity of sweet, salt, sour, and bitter in solutions representing 3 concentrations each of 4 familiar and 4 unfamiliar substances. Significant interpersonal variability was found for all substances. It' was lower for the familiar substances (sucrose, salt, citric acid, and caffein) than for the unfamiliar ones (sodium benzoate, monosodium glutamate, potassium chloride, ammonium chloride, and a “model” solution). Thus, learning appears to be important.

1. The effect of the monosodium glutamate on the frozen-storage denaturation of the fish muscle actomyosin was studied by an in vitro model test of the isolated actomyosin as well as by a frozen-storage test of the washed mince of the fish meat. Besides the Naglutamate-free control group, glucose-added and urea-added groups were examined for comparison. 2. In the model test, 0.3M Na-glutamate was found as effective as or even better than 1M glucose in preventing the denaturation of actomyosin as far as the data on the solubility, viscosity, ATPase activity and the ultracentrifugal patterns are concerned (Figs. 2-5). There was not much difference between the results carried out in 0.6M KCl and those in 0.05M KCl. The addition of urea was rather promotive to the denaturation. 3. In 0.6M KCl, the effect of Na-glutamate approached the maximum beyond 0.025M (0.42%) (Fig. 6). 4. The Kamoboko jelly made of the frozen mince with added Na-glutamate was better than those of the control group in the keeping qualities as measured by the jelly strength, folding test and the amount of expressible water, and also by the amount of soluble proteins (Table 1). 5. The present results suggest the applicability of the model test for screening the additives for preventing the freezing denaturation, as well as for studying its mechanism.

HYPERTONIC carbonated and non-carbonated citrate extenders have given highest fertility in storage experiments with semen of the chicken (Hobbs and Harris, 1963 a,b) and turkey (Harris et al., 1963). Turkey semen stored in a CO2 citrate extender with a freezing point depression of −0.91°C. gave highest fertility. The average fertility for semen stored for 6 hours at 2°C. in this extender was 86%, 72%, 71%, and 44% for weeks 1 to 4 after a single insemination, respectively. Bajpai and Brown (1963 a) noted that turkey semen contains a high level of glutamic acid. In studies on stored semen these investigators replaced sodium citrate with monosodium glutamate in the carbonated Illinois Variable Temperature (I.V.T.) extender for bull semen. This extender was compared with Lake's solution and the original I.V.T. extender. The lowest incidence of bent or dead spermatozoa and highest motility were obtained with the glutamate I.V.T. extender. However, fertility was . . .

A single intraperitoneal injection of gold thioglucose to the chicken (Gallus domesticus) and the Japanese quail (Cotrunix cotrunix japonica) showed that the LD 50 of the drug was 0.25mg/g body weight for White Leghorn 12-day-old cockerels, 0.1mg/g for the adult male quail and more than 0.1mg/g for the adult female quail.Neither growth promotion nor increase in feed consumption was observed in the cockerel and the quail which received the LD 50 dose of gold thioglucose, as compared with the cockerel and quail which did not receive the drug. No hyperphagia or obesity was observed in the gold thioglucose-treated-chicken and quail.No damage to the ventromedial nucleus in hypothalamus was observed in the gold thioglucose-treated-cockerels (Courtesy to the inspection by Dr. Shigeto Kanematsu, Iwate University, Morioka-shi).Subcutaneous injections of monosodium glutamate at the dosage level of 0.5, 1 and 2mg/g body weight for 10 days to the 3-day-old quail of both sexes did not induce any accerelation of growth or increase in feed consumption as compared with the nontreated control birds.

A gas chromatographic method is described for the assay of primary amino groups. The technique is a modification of the Van Slyke method, in which the N2 liberated by the reaction of primary amino groups with nitrous acid is measured by GC. The assay of amino acids, monosodium glutamate, Shake'n Bake and Adolph's Sugar Substitute is described.

The synergistic effect of the taste of monosodium glutamate (MSG) and disodium 5'-guanylate•7H2O (GMP) was studied by the sensory tests. As to the intensity of the taste, the relationship was expressed by the following equation: y=u+γ'uv'where u and v' (g/100ml) are concentrations of MSG and GMP, respectively, in a given MSG-GMP mixture, y (g/100ml) is the concentration of MSG alone equivalent to the taste intensity of the mixture, and γ' is a constant. The γ' was determined as 2.8×103 and 2.3 times larger than the value in the case of MSG and disodium 5'-inosinate•7.5H2O (IMP) mixture. For the quality of taste, no difference can be detected between the equivalent intensity of IMP and GMP except the cases of extremely higher concentrations.