Amazoniac
Member
..and can exacerbate a deficiency, especially in large amounts.
Toxicity of Glycine for Vitamin B12-Deficient Chicks.† <- Crosses like this are scary.
"Twenty-eight day-old White Leghorn chicks which had been fed the vito B12-deficient diet shown in Table I from the day of hatching were used in this experiment. A deficient control group received no treatment, whereas 3 mcg of vit. B12 per week were injected subcutaneously into the chicks of the supplemented group."
"[..]capsules containing 1g of glycine were force-fed[..]"
"Two hours after the glycine administration, the birds of both the deficient and supplemented groups seemed normal with respect to appearance and behavior. Four hours after the glycine dosage, a dramatic change appeared in the vito Bl2-deficient chicks. Two had died and those which remained alive were extremely weak and semicomatose. Several were unable to stand and appeared near death. It was extremely difficult to obtain blood from these birds, probably because of circulatory failure. In marked contrast. the vito B12-treated chicks appeared normal and lively."
A second experiment, food was available the whole time:
"Four hours after glycine feeding, the chicks of the vito B12-deficient group were noticeably listless although they were only slightly affected when compared with the starved B12-deficient chicks of the first trial. The B12-injected birds again seemed normal."
"[..]These high levels [of nitrogen in the blood] were associated with the toxic effect of the glycine. It was interesting to note that vit. B12-deficient chicks which were on feed during the whole period were not as affected by the glycine as those which were starved. It is possible that energy as well as vit. B12 is required in nitrogen metabolism."
Summary:
"The plasma levels for nonprotein nitrogen and amino nitrogen after administration of glycine were higher in vit. B12-deficient chicks than in B12-injected chicks. One gram of glycine, when force fed in gelatin capsules, was toxic to starved, B12-deficient chicks and less toxic to B12-deficient chicks which had not been starved. Chicks which had been injected with vito Bl2 were able to withstand the glycine whether or not they had been without food."
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Action of Vitamin B12 in Counteracting Glycine Toxicity in the Chick.
"Recently, Charkey et al. (7) have demonstrated that the levels of nonprotein nitrogen and amino acids in the blood were higher in vitamin B12-deficient chicks than in chicks fed vitamin B12 (Merck & Co., APF Supplement So. 3). These workers concluded that vitamin B12 appears to function in metabolism by enhancing the utilization of circulating amino acids for building fixed tissues."
For the experiment they first depleted (no b12 and 35% protein) the birds; then 3 groups received b12 in increasing amounts for each, another 3 groups same thing but with 1% of additional glycine.
For the second experiment the protein was lower (21% and extra sugar to compensate the decrease); same thing except that now it was 4% of added glycine.
"This experiment was discontinued at the end of two weeks. since the addition of 4% glycine to the vitamin B12-low basal diet resulted in 75% mortality. Nevertheless, the inhibitory action of this level of glycine on vitamin B12-deficient chicks appears clearly evident even in this brief test period."
"It is evident that the growth of vitamin Bl2-deficient chicks was depressed by the addition of 1% glycine to the diet when no vitamin B12 was supplied, This growth-inhibitory action of glycine was counteracted by the addition of either 3 or 30 micrograms of vitamin Blz per kilogram of diet."
"The effect of 4% added glycine in the vitamin Bl2-deficient diet was striking. Only 3 of the 12 original chicks fed this diet (Group 2) survived the 2-week period. However, the addition of as little as 3 mcg of vitamin B12 per kilo of diet (Group 4) prevented the excessive mortality and completely counteracted the growth-inhibitory action of the added glycine, confirming the results obtained in Exp. 1."
"[..]the retarded growth and extreme mortality which was observed in vitamin B12-deficient chicks fed the high level of glycine may be assumed to have resulted from a specific glycine imbalance rather than from a change in the protein level of the diet. Since the addition of vitamin B12 to all diets containing 1% or 4% added glycine counteracted the inhibitory action of this amino acid on chick growth, it appears that vitamin B12 functions in some manner in the metabolism of glycine."
"This finding is comparable with those of Groschke and Briggs (9) and Anderson et al. (10) of this laboratory, who found that niacin and pyridoxine, respectively, are also concerned in the metabolism of glycine."
"Groschke and Briggs (9) demonstrated that glycine was highly “pellagragenic” when fed to chicks receiving a niacin-low diet. However, they found that as much as 6% glycine could be included in the chick diet with no adverse effects when an adequate amount of nicotinic acid was supplied. Anderson et al. (10) similarly showed that the addition of 4% glycine to a pyridoxine-low diet exerted a growth-depressing action in the chick. This was overcome by the addition of pyridoxine."
"Dinning et al. (11) and Martel et al. (12) observed that rats fed diets containing 10% glycine grew at a subnormal rate."
"Martin (14) reported that glycine was more toxic when fed at high levels to riboflavin-deficient rats than when fed to rats maintained on a diet adequate in riboflavin."
"The results of the present investigation together with those of the workers referred to above indicate that vitamin B12, nicotinic acid, pyridoxine, folic acid, and riboflavin are required in the metabolism of glycine. This appears to be particularly true when unusually large amounts of glycine are fed."
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So, if you supplement gelatin, b12-rich foods deserve special attention.
I also read that some people that had problems with b12 malabsorption managed to solve the issues with a course of tetracycline.
--
Relevant: Sign In
--
jyb, before any comment, @whit already told me that these studies are cruel but valid. Speaking of him, little did Blossom know that I asked him how should I compliment a female for her looks, he replied: "Dunno man, I simply tell that they are cute chicks". Now you know it wasn't detogarory. #houdini
Toxicity of Glycine for Vitamin B12-Deficient Chicks.† <- Crosses like this are scary.
"Twenty-eight day-old White Leghorn chicks which had been fed the vito B12-deficient diet shown in Table I from the day of hatching were used in this experiment. A deficient control group received no treatment, whereas 3 mcg of vit. B12 per week were injected subcutaneously into the chicks of the supplemented group."
"[..]capsules containing 1g of glycine were force-fed[..]"
"Two hours after the glycine administration, the birds of both the deficient and supplemented groups seemed normal with respect to appearance and behavior. Four hours after the glycine dosage, a dramatic change appeared in the vito Bl2-deficient chicks. Two had died and those which remained alive were extremely weak and semicomatose. Several were unable to stand and appeared near death. It was extremely difficult to obtain blood from these birds, probably because of circulatory failure. In marked contrast. the vito B12-treated chicks appeared normal and lively."
A second experiment, food was available the whole time:
"Four hours after glycine feeding, the chicks of the vito B12-deficient group were noticeably listless although they were only slightly affected when compared with the starved B12-deficient chicks of the first trial. The B12-injected birds again seemed normal."
"[..]These high levels [of nitrogen in the blood] were associated with the toxic effect of the glycine. It was interesting to note that vit. B12-deficient chicks which were on feed during the whole period were not as affected by the glycine as those which were starved. It is possible that energy as well as vit. B12 is required in nitrogen metabolism."
Summary:
"The plasma levels for nonprotein nitrogen and amino nitrogen after administration of glycine were higher in vit. B12-deficient chicks than in B12-injected chicks. One gram of glycine, when force fed in gelatin capsules, was toxic to starved, B12-deficient chicks and less toxic to B12-deficient chicks which had not been starved. Chicks which had been injected with vito Bl2 were able to withstand the glycine whether or not they had been without food."
--
Action of Vitamin B12 in Counteracting Glycine Toxicity in the Chick.
"Recently, Charkey et al. (7) have demonstrated that the levels of nonprotein nitrogen and amino acids in the blood were higher in vitamin B12-deficient chicks than in chicks fed vitamin B12 (Merck & Co., APF Supplement So. 3). These workers concluded that vitamin B12 appears to function in metabolism by enhancing the utilization of circulating amino acids for building fixed tissues."
For the experiment they first depleted (no b12 and 35% protein) the birds; then 3 groups received b12 in increasing amounts for each, another 3 groups same thing but with 1% of additional glycine.
For the second experiment the protein was lower (21% and extra sugar to compensate the decrease); same thing except that now it was 4% of added glycine.
"This experiment was discontinued at the end of two weeks. since the addition of 4% glycine to the vitamin B12-low basal diet resulted in 75% mortality. Nevertheless, the inhibitory action of this level of glycine on vitamin B12-deficient chicks appears clearly evident even in this brief test period."
"It is evident that the growth of vitamin Bl2-deficient chicks was depressed by the addition of 1% glycine to the diet when no vitamin B12 was supplied, This growth-inhibitory action of glycine was counteracted by the addition of either 3 or 30 micrograms of vitamin Blz per kilogram of diet."
"The effect of 4% added glycine in the vitamin Bl2-deficient diet was striking. Only 3 of the 12 original chicks fed this diet (Group 2) survived the 2-week period. However, the addition of as little as 3 mcg of vitamin B12 per kilo of diet (Group 4) prevented the excessive mortality and completely counteracted the growth-inhibitory action of the added glycine, confirming the results obtained in Exp. 1."
"[..]the retarded growth and extreme mortality which was observed in vitamin B12-deficient chicks fed the high level of glycine may be assumed to have resulted from a specific glycine imbalance rather than from a change in the protein level of the diet. Since the addition of vitamin B12 to all diets containing 1% or 4% added glycine counteracted the inhibitory action of this amino acid on chick growth, it appears that vitamin B12 functions in some manner in the metabolism of glycine."
"This finding is comparable with those of Groschke and Briggs (9) and Anderson et al. (10) of this laboratory, who found that niacin and pyridoxine, respectively, are also concerned in the metabolism of glycine."
"Groschke and Briggs (9) demonstrated that glycine was highly “pellagragenic” when fed to chicks receiving a niacin-low diet. However, they found that as much as 6% glycine could be included in the chick diet with no adverse effects when an adequate amount of nicotinic acid was supplied. Anderson et al. (10) similarly showed that the addition of 4% glycine to a pyridoxine-low diet exerted a growth-depressing action in the chick. This was overcome by the addition of pyridoxine."
"Dinning et al. (11) and Martel et al. (12) observed that rats fed diets containing 10% glycine grew at a subnormal rate."
"Martin (14) reported that glycine was more toxic when fed at high levels to riboflavin-deficient rats than when fed to rats maintained on a diet adequate in riboflavin."
"The results of the present investigation together with those of the workers referred to above indicate that vitamin B12, nicotinic acid, pyridoxine, folic acid, and riboflavin are required in the metabolism of glycine. This appears to be particularly true when unusually large amounts of glycine are fed."
--
So, if you supplement gelatin, b12-rich foods deserve special attention.
I also read that some people that had problems with b12 malabsorption managed to solve the issues with a course of tetracycline.
--
Relevant: Sign In
--
jyb, before any comment, @whit already told me that these studies are cruel but valid. Speaking of him, little did Blossom know that I asked him how should I compliment a female for her looks, he replied: "Dunno man, I simply tell that they are cute chicks". Now you know it wasn't detogarory. #houdini
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