Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The acute effects of arginine vasotocin (AVT), a putative pineal peptide, on plasma levels of prolactin were investigated in the unanesthetized, estrogen-progesterone-treated male rat. A 10-microgram s.c. injection resulted in significantly increased levels of prolactin while a 1-microgram injection depressed plasma levels of this hormone; an inhibition of release was further suggested by increased levels of pituitary prolactin in rats treated with the lower dose. The same dose administered subcutaneously to urethane-anesthetized rats had no significant effect on plasma prolactin titers while a 10-microgram dose was still stimulatory. In anesthetized rats, no dose of the AVT administered (1 ng to 10 micrograms, s.c., or 1 fg to 1 microgram, i.v.) resulted in inhibition of prolactin release. In the unanesthetized normal male rat, 5 micrograms AVT first increased and then decreased levels of prolactin. Urethane anesthesia appears to mask an inhibitory effect of AVT on plasma prolactin levels in these animal preparations. Since AVT is capable of decreasing plasma prolactin levels, this peptide might be involved in the depression of plasma prolactin levels which appears to (at least partially) mediate pineal-induced gonadal degeneration.
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PMID:Acute effects of arginine vasotocin on plasma and pituitary levels of prolactin in the male rat: influence of urethane anesthesia. 678 80

The ability of amino acids inhibitory of lysine transport into brain slices to induce lysine imbalance was determined by feeding wheat gluten or casein diets with additions of such amino acids. Lysine transport was only moderately inhibited by amino acids; the most effective were basic amino acids or mixtures of indispensable (IAA) or branched chain amino acid (BCAA). Only mild depressions in growth and food intake occurred during a 10-day period when male, 60--65 g rats of the Sprague-Dawley strain were fed lysine-limiting, 18% wheat gluten diets with additions of these amino acids. The effects were prevented by added lysine. Rats allowed a choice between the lysine-imbalanced or non-protein diets selected the imbalanced, wheat gluten diets (in severe imbalances rats will choose the non-protein diet). Growth depression, prevented by added lysine, occurred in rats fed a 6% casein diet supplemented with IAA; individual amino acids were ineffective. Growth depressions also occurred when rats were fed a basal diet containing 6% case in + 5% of an equimolar mixture of nine IAA and supplemented with arginine or more IAA; BCAA were less effective. Additional lysine completely prevented the growth depressions, but growth of rats fed the diets containing arginine and BCAA was greater than that of those fed the extra IAA. It is difficult to induce a severe lysine imbalance; this is consistent with the failure of amino acids to cause under our conditions strong inhibition of lysine transport into brain.
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PMID:Induction of lysine imbalance in rats: relation to competition for lysine transport into the brain in vitro. 678 81

Two 14-day factorial experiments were performed to assess changes in growth, feed intake and urinary orotic acid excretion of weanling male Sprague-Dawley rats. The dietary variables investigated included the percentage of dietary casein in the basal diet, its supplementation with 5% lysine-HCl or 1% arginine-HCl and sucrose or two parts dextrin and one part sucrose as the only form of carbohydrate. The response to 5% supplemental lysine was strikingly similar to that seen with arginine-free diets. With 5% lysine added to 15% casein diets, growth decreased 25% and feed efficiency 20% while orotic acid excretion increased significantly. When 5% lysine was added to diets with 7.5 or 30% casein, these responses were smaller and were prevented by the simultaneous feeding of 1% arginine. Growth depression by lysine was partially reversed by replacing two-thirds of the dietary sucrose with dextrin. When unsupplemented, the casein diets containing only sucrose as carbohydrate supported less growth than the same diets containing the dextrin sucrose mixture. This difference was abolished by supplementation with 1% arginine, suggesting that sucrose increases arginine requirements for optimal growth. The data are consistent with the conclusion that orotic acid excretion is a useful index for determining when lysine excess is producing a functional deficiency of arginine.
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PMID:Orotic aciduria caused by feeding excess lysine to growing rats. 679 1

Nutritional interactions between dietary chloride and lysine in the young chick were investigated. Chloride, varying over four levels from .44 to 1.84% of the diet, was included in diets containing limiting (.7%) or adequate (1.1%) levels of lysine. Increasing chloride in diets containing either level of lysine resulted in a depression of growth rate and feed consumption (P less than .01). The efficiency of feed utilization for growth was significantly lowered only when chicks were fed diets containing the highest level of chloride (P less than .05). Plasma lysine concentrations were greater in chicks fed the lysine adequate diet; plasma arginine was unchanged. Plasma lysine and arginine concentrations were unaffected by chloride. In a second experiment chicks were fed a lysine deficient (.7%), lysine adequate (1.2%), high lysine (2.5%), or high lysine (2.5%) high arginine (2.3%) diet with varying levels of chloride. Increasing dietary chloride depressed weight gains. This effect was most dramatic in those chicks fed the high lysine diet. Increasing dietary arginine alleviated the effect of chloride in the high lysine diet. Plasma sodium and potassium were unaffected by dietary lysine and chloride levels. Plasma chloride tended to be greater in chicks receiving high chloride diets and were highest in chicks fed the high lysine diet. We conclude that dietary chloride does not influence the lysine requirement of chicks but exacerbates the lysine-arginine antagonism.
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PMID:Lysine-chloride interactions in the growing chick. 679 59

Rats fed a purified L-amino acid diet with 0.72, 1.50, 2.9 or 4.3% lysine excreted 117, 124, 237 and 628 micrograms/day orotic acid, respectively. Dietary arginine supplementation prevented the orotic aciduria induced by excess dietary lysine. Increased orotic acid excretion was accompanied by a significant depression in urinary urea in rats fed a diet containing 4.3% lysine compared to those fed a diet containing 0.72% lysine. As measured by incorporation of [14C]HCO3, lysine addition to liver slices or isolated hepatocytes resulted in a progressive increase in the rate of orotic acid biosynthesis. The minimum quantity of lysine tested that significantly increased the rate of orotic acid biosynthesis was 0.5 mM or 1 mM for studies with slices and hepatocytes, respectively. Ammonia at concentrations of 0, 0.75, or 5.0 mM NH4Cl linearly increased orotate and urea synthesis. Inhibition of urea biosynthesis resulting from lysine supplementation coincided with an increase in pyrimidine biosynthesis. Addition of 1 mM arginine to the liver incubation media prevented the increased rate of orotic acid biosynthesis caused by lysine. Arginine addition may overcome an approximate 90% competitive inhibition of arginase by excess lysine.
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PMID:The influence of excess lysine on urea cycle operation and pyrimidine biosynthesis. 681 6

Arg mutants, isolated from Streptomyces lavendulae at unusually high frequencies, showed several phenotypic characteristics. The characteristics common to all arg mutants include: (1) repression of beta-lactamase production, (2) inhibition of aerial mycelium formation, (3) development of acid pH, (4) low saturation density of growth in liquid culture, (5) a decrease in antibiotic production, (6) an increase in sensitivity to benzylpenicillin and (7) a decrease in production of pigment. These results suggest that the arg mutation concomitantly caused the depression of secondary metabolism in S. lavendulae.
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PMID:Multiple effects induced by unstable mutation in Streptomyces lavendulae. 696 67

Many polar fishes synthesize a group of eight glycopeptides that exhibit a non-colligative lowering of the freezing point of water. These glycopeptides range in molecular weight between 2600 and 33 700. The largest glycopeptides [1-5] lower the freezing point more than the small ones on a weight basis and contain only two amino acids, alanine and threonine, with the disaccharide galactose-N-acetyl-galactosamine attached to threonine. The small glycopeptides, 6, 7, and 8, also lower the freezing point and contain proline, which periodically substitutes for alanine. Glycopeptides with similar antifreeze properties isolated from the saffron cod and the Atlantic tomcod contain an additional amino acid, arginine, which substitutes for threonine in glycopeptide 6. In this study we address the question of whether differences in amino acid composition or molecular weight between large and small glycopeptides are responsible for the reduced freezing point depressing capability of the low molecular weight glycopeptides. The results indicate that the degree of amino acid substitutions that occur in glycopeptides 6-8 do not have a significant effect on the unusual freezing point lowering and that the observed decrease in freezing point depression with smaller glycopeptides can be accounted for on the basis of molecular weight.
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PMID:Relationship of amino acid composition and molecular weight of antifreeze glycopeptides to non-colligative freezing point depression. 711 72

The chick's choline and methionine requirements are both increased by high dietary protein level. Studies were conducted to test the hypothesis that the chicks' need for preformed methyl groups is increased by high protein diets (not methionine or choline per se). Chicks fed 25% isolated soybean protein (ISP) diets responded to methionine supplementation (162 vs 110 g gained in 14 days) but not to choline (119 g vs. 110 g), while those fed 50% ISP responded to either methionine (174 g vs. 126 g) or choline (181 g vs. 126 g) supplementation. Further, neither cystine nor homocystine could replace methionine in improving the growth of chicks fed the high protein diet. In other experiments, L-methionine and betaine HCl were found to alleviate the growth depression caused by excessive levels of L-glutamic acid. Excessive levels of L-methionine had a protective effect against growth depression caused by L-glutamate and diammonium citrate, and conversely, supplementary L-serine and sodium formate were not protective against glutamic acid- or arginine-induced growth depression. The results are consistent with the hypothesis that the preformed methyl group requirement is increased by high levels of dietary protein and excessive nitrogen from a single amino acid.
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PMID:The effects of high dietary protein and nitrogen levels on the preformed methyl group requirement and methionine-induced growth depression in chicks. 726 36

A corn-soybean (CS) diet and diets containing medium or high levels of animal protein (AP) calculated to contain the same concentrations of the main nutrients promoted essentially the same growth rate and feed utilization in 20-day-old chicks. Supplementation with monensin sodium (100 or 120 mg/kg) depressed growth rate of the chicks fed all three diets. However, effect of the drug was much more severe in chicks fed the diets containing AP. This interaction resulted in significant (P < .05) differences in body weights between chicks fed the CS diet and PA diets. Moreover, feed-to-gain ratio was significantly (P < .05) adversely affected by monensin only in chicks fed the AP diets. Supplementation of the high AP diet with extra vitamin E, a mixture of arginine and tryptophan, or a mixture of silicon, chromium, and molybdenum failed to prevent the growth depression caused by monensin. These studies demonstrate that ingredient composition of diets for broiler chicks affects the magnitude of growth depression caused by monensin supplementation.
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PMID:Effect of dietary ingredients on monensin toxicity in chicks. 741 86

We studied the effects of a nitric oxide synthase (NOS) inhibitor, N omega-nitro-L-arginine-methyl ester (L-NAME), on cardiac depression and bronchospasm provoked by systemic anaphylaxis in vivo in rabbits. Animals pretreated with L-NAME showed lower survival rates than control animals pretreated with normal saline. The survival rate in L-NAME-pretreated animals was increased by the administration of L-arginine after initiation of anaphylaxis. Cardiac output fell significantly in animals pretreated with L-NAME compared with controls, although venous return was increased. In animals pretreated with L-NAME, pulmonary resistance was significantly increased, and administration of arginine attenuated the bronchospasm. In conclusion, these results, along with the low survival rates in the L-NAME-treated animals, suggest that NO production may be beneficial to cardiac depression and bronchospasm in anaphylaxis in vivo.
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PMID:Nitric oxide synthase inhibition is detrimental to cardiac function and promotes bronchospasm in anaphylaxis in rabbits. 749


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