Guest guest Posted December 30, 2003 Report Share Posted December 30, 2003 you can see why ala chelation is so uneven with its spilling of zinc. anyway susan has not posted this here so i am taking the liberty of doing so " From: Owens <lwo@i...> Date: Wed Dec 31, 2003 2:07 am Subject: The relationship between zinc deficiency and sulfur excretion Listmates, I've been analyzing the data from a paper which looked at rats, but compared two groups: one that had adequate zinc in its diet, and another group where zinc was restricted. This restriction continued for three weeks, but every week, the authors looked at their excretion of labelled sulfate and labelled taurine that was derived from a dose of labelled cystine.. What the study found is that by the third week of zinc restriction, the rats were excreting five times the normal amount of taurine, and three and a half times the normal amount of sulfate that was derived from that cystine. It was amazing how the differences in just one more week of zinc being low made the curve for the amount of this sulfur loss go up dramatically, and since they stopped at three weeks, we don't know how much more restriction for even longer would have affected the loss of sulfur in urine. They did another test in a different group of rats and measured things after two weeks of zinc restriction, but this time they compared the total sulfur or the sulfate excreted when it was derived (was metabolized from) various different sulfur compounds. In this time frame, the labelled sulfur excreted was about one and a half times normal if the source of the sulfur was thiamine or thiourea and just a bit higher than that if the source were cystine. If the original source of the label were sulfate, it was just a bit lower than one and a half times normal, but if the source of the label were methionine, the loss was about double. When they only looked at labelled sulfate alone that was being excreted under these conditions, the excretion rate in zinc deficiency was a bit higher proportionately than had been the labelled sulfur, but the real difference occurred when methionine was the source of the labelled sulfur, for then the zinc deficient rats excreted three and three/quarters the amount of sulfate as the rats who had been on a diet restricting zinc for two weeks. The study suggested that this difference derived from the difficulty the rats would have had trying to use methionine to form proteins under the zinc deficient condition, so they suggested that the methionine, instead of being incorporated into proteins, was instead being broken down to sulfate. Another study had actually already shown that zinc deficiency made it more difficult to use methionine for building proteins. Of course this study was in rats, and we humans might be a bit differerent, but the study does need to make us think how terrifically important zinc is to sulfur homeostasis. If you lose sulfur in the urine, as happens in HIV, you might develop problems maintaining body stores of sulfur with unfortunate consequences. Curiously, zinc deficiency occurs in HIV, and the degree of deficiency is somewhat predictive of survival. However, those with HIV are known to dump sulfate in high quantities in the urine from the first days of infection and long before the symptoms of AIDS shows up. This has been quantified to represent a loss equivalent to 4.4 pounds of excess sulfate loss in urine every year. This is such a high proportion of the body's sulfur stores that it is not surprising this disease becomes fatal. Doe this connection with AIDS maybe hint at how activation of the immune system may deplete zinc? Last night I took a look at the literature to see if I could find information about what depletes zinc or causes us to lose zinc, and I wasn't very successful finding a lot of discussion of this area, so I hope perhaps some other listmates may have had more success in the past. By the way, predictably, zinc deficiency retards growth, which is quite logical if it depletes sulfur and keeps cells from using their methionine to make protein. One of the things this perhaps should make us think about is how a lot of doctors and parents have been beefing up zinc before initiating chelation and during chelation in children they were treating with DMSA or other chelating agents. If this extra zinc actually helped these children retain sulfur, then that (even if it were not followed by chelation) would have improved their sulfur chemistry and their ability to deal with heavy metals, especially since if you improve their sulfur status, then they can make more metallothionein whose main amino acid component is cysteine. Those who find they are excreting high levels of taurine or sulfate may need to take a closer look at zinc status. Does this information jibe with the personal experience of listmates who have found their children improved with zinc supplementation? I'm thinking of you, mainly, ! Be sure and read the abstracts below if this is an area of interest to you. J Nutr. 1970 Oct;100(10):1189-95. Related Articles, Links Zinc deficiency and urinary excretion of taurine-35S and inorganic sulfate-35S following cystine-35S injecion in rats. Hsu JM, WL. PMID: 5471053 [PubMed - indexed for MEDLINE] Clin Infect Dis. 2003;37 Suppl 2:S117-23. Related Articles, Links [Click here to read] Zinc status in human immunodeficiency virus type 1 infection and illicit drug use. Baum MK, Campa A, Lai S, Lai H, Page JB. Florida International University, College of Health and Urban Affairs, University Park, Rm. HLS 337, Miami, FL 33199, USA. baumm@f... Zinc deficiency is the most prevalent micronutrient abnormality seen in human immunodeficiency virus (HIV) infection. Low levels of plasma zinc predict a 3-fold increase in HIV-related mortality, whereas normalization has been associated with significantly slower disease progression and a decrease in the rate of opportunistic infections. Studies in Miami, Florida, indicated that HIV-positive users of illicit drugs are at risk for developing zinc deficiency, at least partially because of their poor dietary intake. Zinc deficiency characterized by low plasma zinc levels over time enhances HIV-associated disease progression, and low dietary zinc intake is an independent predictor of mortality in HIV-infected drug users. The amount of zinc supplementation in HIV infection appears to be critical, because deficiency, as well as excessive dietary intake of zinc, has been linked with declining CD4 cell counts and reduced survival. More research is needed to determine the optimal zinc supplementation level in HIV-infected patients, to prevent further burden on an already compromised immune system. PMID: 12942385 [PubMed - indexed for MEDLINE] AIDS Res Hum Retroviruses. 2000 Feb 10;16(3):203-9. Related Articles, Links [Click here to read] Massive loss of sulfur in HIV infection. Breitkreutz R, Holm S, Pittack N, Beichert M, Babylon A, Yodoi J, Droge W. Division of Immunochemistry, Deutsches Krebsforschungszentrum, Heidelberg, Germany. Skeletal muscle tissue from SIV-infected macaques was previously found to contain abnormally high sulfate and low glutathione levels indicative of an excessive cysteine catabolism. We now confirm the peripheral tissue as a site of massive cysteine catabolism in HIV infection and have determined the urinary loss of sulfur per time unit. The comparison of the sulfate concentrations of the arterial and venous blood from the lower extremities of 16 symptomatic HIV+ patients and 18 HIV- control subjects (study 1) revealed (1) that the peripheral tissue of HIV+ patients with or without highly active antiretroviral therapy (HAART) releases large amounts of sulfate and (2) that plasma sulfate, thioredoxin, and interleukin-6 levels are elevated in these patients. A complementary investigation of 64 asymptomatic HIV+ patients and 65 HIV- subjects (study 2) revealed increased plasma sulfate levels in the asymptomatic patients. The analysis of the daily urinary excretion of sulfate and urea of another group of 19 HIV+ patients and 22 healthy HIV- subjects (study 3) confirmed (1) that HIV+ patients experience a massive loss of sulfur and (2) that this loss is not ameliorated by HAART. The sulfur loss of asymptomatic patients was equivalent to a mean loss of about 10 g of cysteine per day. If extrapolated, this would correspond to an alarming negative balance of approximately 2 kg of cysteine per year under the assumption that the normal sulfate excretion equivalent to approximately 3 g of cysteine per day is balanced by a standard Western diet. The abnormally high sulfate/urea ratio suggests that this process drains largely the glutathione pool. PMID: 10710208 [PubMed - indexed for MEDLINE] J Trop Pediatr. 2003 Jun;49(3):187-8. Related Articles, Links Zinc deficiency: a contributing factor of short stature in growth hormone deficient children. Siklar Z, Tuna C, Dallar Y, Tanyer G. Ministry of Health Ankara Hospital, Department of Pediatrics, Turkey. zeynepsklr@h... Zinc is an essential trace element which affects growth by promoting DNA and RNA synthesis and cell division. Zinc deficiency causes growth retardation and its frequency is high in developing countries. It could contribute to the effect of growth hormone (GH) treatment in GH deficient children. In this study, we investigated zinc deficiency in GH children. Twenty-four GH deficient children (treated with GH for 2.2 +/- 1.6 years) were recruited for the study. Intracellular erythrocyte zinc levels were measured. Eleven (45.9 per cent) were found to be zinc deficient (Group 1), while 13 patients (54.1 per cent) had normal zinc levels (Group 2). The mean growth velocity was 5.98 +/- 0.8 cm/year in Group 1 and 6.9 +/- 1.4 cm/year in Group 2. Group 2 was given oral zinc supplementation with a resultant growth velocity of 7.51 +/- 0.5 cm/year. During GH treatment in GH deficient children, zinc status should be evaluated as severe zinc deficiency could affect the response to GH treatment. PMID: 12848213 [PubMed - indexed for MEDLINE] Quote Link to comment Share on other sites More sharing options...
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