Tag Archives: positive

Zinc Inhibits Stimulatory Effect of TGF-β on Mouse Osteoclasts

Abstract

Differential effects of transforming growth factor-beta on osteoclast-like cell formation in mouse marrow culture: relation to the effect of zinc-chelating dipeptides.

The effect of transforming growth factor-beta (TGF-beta) on osteoclast-like cell formation in mouse marrow culture in vitro was investigated. The bone marrow cells were cultured for 7 days in alpha-minimal essential medium containing a well-known bone resorbing agent. Osteoclast-like cell formation was estimated with staining for tartrate-resistant acid phosphatase (TRACP), a marker enzyme of osteoclasts. The presence of TGF-beta (10(-13)-10(-11) M) caused a significant increase in the number of osteoclast-like multinucleated cells (MNCs); the maximum effect was seen with 10(-12) MTGF-beta. With a higher concentration (10(-10) M) of TGF-beta, the growth factor dramatically inhibited the 1,25-dihydroxyvitamin D5 [1,25(OH)2D3; 10(-8) M]-induced formation of osteoclast-like MNCs. This inhibitory effect was also seen in the formation of osteoclast-like MNCs stimulated by parathyroid hormone (10(-8) M), prostaglandine E2 (10(-6) M), and interleukin-1 alpha (50 U/ml). The stimulatory effect of TGF-beta (10(-12) M) on osteoclast-like MNCs formation was inhibited by zinc sulfate (10(-6) M) or zinc-chelating dipeptide [beta-alanyl-L-histidinato zinc (AHZ), 10(-6) M]. The stimulating effect of TGF-beta was markedly weakened by the presence of EGTA (0.5 mM), a chelator of Ca2+. The inhibitory effect of zinc compounds was not seen in the presence of EGTA. Moreover, the inhibitory effect of TGF-beta (10(-10) M), zinc sulfate (10(-6) M), or AHZ (10(-6) M) on osteoclast-like MNCs formation was not demonstrated in mature osteoclastic cells, although calcitonin (3 x 10(-8) M) significantly inhibited the osteoclastic formation. The present study demonstrates that TGF-beta has a stimulating and an inhibiting effect on osteoclast-like cell formation in mouse marrow culture, and that zinc can inhibit the stimulatory effect of TGF-beta.

Yamaguchi M, Kishi S
Peptides 1995
PMID: 8745062

Zinc Restores Bone After Unloading in Rats

Abstract

Zinc decrease and bone metabolism in the femoral-metaphyseal tissues of rats with skeletal unloading.

Whether the decrease of zinc content in the femoral-metaphyseal tissues of rats with skeletal unloading is involved in the alteration of bone metabolism was investigated. Skeletal unloading was designed using the model of hindlimb suspension in rats. Animals were fed for 4 days with the unloading. The metaphyseal zinc content were significantly decreased by the unloading. Zinc accumulation in the metaphyseal tissues by a single oral administration of zinc sulfate (20 mg Zn/100 g body weight) was partially depressed by the unloading, although serum zinc concentration was higher than that in normal rats, suggesting an impaired movement of zinc from serum into bone tissues by the unloading. Skeletal unloading caused a significant decrease of alkaline phosphatase activity and deoxyribonucleic acid (DNA) content in the metaphyseal tissues. These decreases were completely restored by addition of zinc sulfate (10(-4) M) or beta-alanyl-L-histidinato zinc (AHZ; 10(-5) M) in a culture medium with the metaphyseal tissues in vitro. The effects of zinc compounds were abolished by the presence of cycloheximide (10(-8) M), suggesting that the zinc effect is based on a newly synthesized protein. Dipicolinate (10(-4) and 10(-5) M), a potent zinc-chelating agent, caused an appreciable decrease of zinc content and alkaline phosphatase activity in the metaphyseal tissues. This decrease was restored by zinc supplement. The present results suggest that the skeletal unloading-induced decrease of zinc content in the femoral-metaphyseal tissues plays a role in the deterioration of bone metabolism in the unloaded rats.

Yamaguchi M, Ehara Y
Calcif. Tissue Int. Sep 1995
PMID: 8574940

Zinc-Carnosine > Zinc at Stimulating Bone Growth in Rats

Abstract

A new zinc compound, beta-alanyl-L-histidinato zinc, stimulates bone growth in weanling rats.

The effect of a new zinc compound. beta-alanyl-L-histidinato zinc (AHZ), on bone metabolism in weanling rats was investigated. Rats were orally administered AHZ (0.5-2.5 mg/100 g body weight) for 3 days, and 24h later they were killed. Administration of AHZ (1.0 and 2.5 mg/100 g) caused a significant increase of zinc content in the femoral diaphysis and a corresponding elevation of calcium content, alkaline phosphatase activity, and DNA content. A dose of 0.5 mg/100g AHZ did not produce an appreciable increase in bone components. When zinc sulfate (0.55 mg Zn/100g) was orally administered in rats for 3 days, the bone zinc content, calcium content, and alkaline phosphatase activity were raised significantly, but bone DNA content was not appreciably affected. Thus, the stimulation of AHZ (2.5 mg/100g), which corresponds to 0.55 mg Zn/100g, on bone metabolism was more intensive than that of zinc sulfate. These results suggest that AHZ can stimulate bone growth in weanling rats, and that the compound has a greater effect in comparison with zinc sulfate.

Yamaguchi M, Ozaki K
Res Exp Med (Berl) 1990
PMID: 2349394

Zinc-Carnosine > Zinc at Stimulating Osteoblasts In Vitro

Abstract

Effect of zinc-chelating dipeptides on osteoblastic MC3T3-E1 cells: activation of aminoacyl-tRNA synthetase.

The effect of zinc-chelating dipeptides on osteoblastic MC3T3-E1 cells was investigated. As zinc compounds, we used zinc sulfate, AHZ, di(N-acetyl-beta-alanyl-L-histidinato)zinc (AAHZ), and di(histidino)zinc (HZ). Cells were cultured for 72 h in the presence of zinc compounds (10(-8)-10(-5) M). The effect of AHZ (10(-7) and 10(-6) M) to increase protein and deoxyribonucleic acid (DNA) contents in the cells was the greatest in comparison with those of other zinc compounds. Zinc sulfate and HZ at 10(-7) M did not have an effect on the cellular protein content. AHZ (10(-6) M) had a potent effect on cell proliferation, although zinc sulfate (10(-6) M) had no effect. beta-Alanyl-L-histidine (10(-6) and 10(-5) M) did not have an appreciable effect on the cells. Those effects of AHZ (10(-6) M) on osteoblastic cells were completely abolished by the presence of cycloheximide (10(-6) M). AHZ (10(-8)-10(-5) M) directly activated [3H]leucyl-tRNA synthetase in the cell homogenate, whereas the effect of zinc sulfate was seen at 10(-6) and 10(-5) M. The present study suggests that the chemical form of zinc-chelating beta-alanyl-L-histidine (AHZ) can reveal a potent anabolic effect on osteoblastic cells, and that AHZ directly stimulates protein synthesis.

Yamaguchi M, Kishi S, Hashizume M
Peptides 1994
PMID: 7700838

Zinc-Carnosine Prevents Effects of Aluminium on Bone in Rats

Abstract

Beta-alanyl-L-histidinato zinc prevents the toxic effect of aluminium on bone metabolism in weanling rats.

The preventive effect of beta-alanyl-L-histidinato zinc (AHZ) on the toxic action of aluminium on bone metabolism was investigated in the femoral diaphysis of weanling rats. Aluminium chloride (5.0, 10.0 and 20.0 mumol A1/100 g body weight) was orally administered for 3 days. The dose of 10.0 and 20.0 mumol A1/100 g caused a significant increase in serum calcium concentration and bone acid phosphatase activity, while bone alkaline phosphatase activity and calcium content were not altered significantly. Moreover, the bone DNA content was significantly decreased by the doses of 10.0 and 20.0 mumol A1/100 g. Meanwhile, the increase in serum calcium concentration caused by the administration of aluminium (20 mumol/100 g) was completely prevented by the simultaneous administration of AHZ (1.0 and 2.5 mg/100 g) for 3 days, although AHZ alone did not have any effect. Also, the effects of aluminium (20.0 mumol/100 g) to increase bone acid phosphatase activity and to decrease the bone DNA content were completely blocked by the simultaneous administration of AHZ (1.0 and 2.5 mg/100 g). AHZ (1.0 and 2.5 mg/100 g) alone had the effect to increase bone DNA content but not bone acid phosphatase activity. The present study indicates that AHZ can prevent the revelation of the toxic effect of aluminium on bone metabolism in rats.

Yamaguchi M, Ozaki K
Pharmacology 1990
PMID: 2096394

Zinc-Carnosine Stimulates Bone In Vitro

Abstract

Stimulatory effect of beta-alanyl-L-histidinato zinc on bone formation in tissue culture.

The present investigation was undertaken to clarify the in vitro effect of beta-alanyl-L-histidinato zinc (AHZ) on bone metabolism in tissue culture. Calvaria were removed from weanling rats (3-week-old male) and cultured for periods up to 96 h in Dulbecco’s modified Eagle medium (high glucose, 4.5%) supplemented with antibiotics and bovine serum albumin. The experimental cultures contained 10(-8) to 10(-4) mol/l AHZ. The bone cellular zinc content was significantly increased in cultures with concentrations of AHZ greater than 10(-6) mol/l. With 10(-5) mol/l zinc sulfate, the bone cellular zinc content was significantly elevated. Bone calcium content was significantly increased by the presence of 10(-7) to 10(-4) mol/l AHZ. This increase was blocked by the presence of 10(-7) mol/l cycloheximide. Bone alkaline phosphatase activity was elevated in the presence of AHZ (10(-7) to 10(-4) mol/l), whereas it did not significantly alter acid phosphatase activity Bone collagen and DNA contents were significantly increased by 10(-7) to 10(-5) mol/l AHZ, while they were not significantly elevated by zinc sulfate (10(-7) and 10(-6) mol/l). The AHZ (10(-5) mol/l)-induced increase in bone alkaline phosphatase activity and DNA content were prevented by 10(-4) mol/l dipicolinate, a chelator of zinc. Furthermore, the AHZ (10(-5) mol/l)-induced increase in bone alkaline phosphatase activity, collagen and DNA contents were blocked by 10(-7) mol/l cycloheximide. These findings indicate that AHZ had a direct stimulatory effect on bone mineralization in vitro, and that bone protein synthesis was a necessary component of this response. The AHZ effect was more intensive than that of zinc sulfate.

Yamaguchi M, Miwa H
Pharmacology 1991
PMID: 1852783

Zinc-Carnosine Inhibits Bone Resorption In Viro

Abstract

Inhibitory effect of beta-alanyl-L-histidinato zinc on bone resorption in tissue culture.

The inhibitory effect of beta-alanyl-L-histidinato zinc (AHZ) on bone resorption in tissue culture was investigated. Calvaria were removed from weanling rats (3-week-old male) and cultured for periods up to 48 h in Dulbecco’s modified Eagle medium (high glucose, 4.5%) supplemented with antibiotics and bovine serum albumin. The experimental cultures contained 10(-7) to 10(-4) mol/l AHZ. The bone-resorbing factors, parathyroid hormone (1-34) (PTH; 10(-7) mol/l), prostaglandin E2 (10(-5) mol/l), interleukin-1 alpha (IL1 alpha; 50 U/ml), and lipopolysaccharide (10 micrograms/ml), caused a significant decrease in bone calcium content. The decreases in bone calcium content induced by bone-resorbing factors were completely inhibited by the coexistence of AHZ (10(-6) to 10(-4) mol/l). Also, AHZ (10(-5) mol/l) completely inhibited the PTH (10(-7) mol/l) or IL1 alpha (50 U/ml)-induced increase in medium glucose consumption and lactic acid production by bone tissue. Furthermore, AHZ (10(-5) mol/l) fairly blocked both PTH (10(-7) mol/l)-increased acid phosphatase and decreased alkaline phosphatase activities of bone tissue. The inhibitory effect of AHZ (10(-5) mol/l) on PTH (10(-7) mol/l)-stimulated bone resorption was clearly prevented by the presence of 10(-4) mol/l dipicolinate, a chelator of zinc. However, zinc sulfate (10(-7) to 10(-4) mol/l) did not inhibit the PTH (10(-7) mol/l)-stimulated bone resorption in tissue culture. These findings indicate that AHZ had a direct inhibitory effect on bone resorption in vitro, and the AHZ effect was found in the chemical form of zinc-chelated dipeptide.

Yamaguchi M, Segawa Y, Shimokawa N, Tsuzuike N…
Pharmacology 1992
PMID: 1465476

Zinc-Carnosine Prevents Hydrocortisone Effects on Bones in Rats

Abstract

beta-Alanyl-L-histidinato zinc prevents hydrocortisone-induced disorder of bone metabolism in rats.

The preventive effect of beta-alanyl-L-histidinato zinc (AHZ) on osteopenia was investigated in rats treated with hydrocortisone. Rats received hydrocortisone (75 mg/kg body weight per day) s.c. for 30 days. The steroid treatment caused a significant increase in serum alkaline phosphatase activity and parathyroid hormone (PTH-c) level, while serum calcium, inorganic phosphorus, and zinc concentrations were not significantly altered. The femoral-diaphyseal alkaline phosphatase activity, deoxyribonucleic acid (DNA), and calcium contents were significantly decreased by the treatment of steroid, although the bone zinc content was not appreciably altered. When AHZ (10, 30, and 100 mg/kg per day) was administered p.o. for 30 days to rats giving the steroid, the dose of AHZ (30 and 100 mg/kg) completely prevented the increases in serum alkaline phosphatase activity and PTH-c level and the decreases in femoral-diaphyseal alkaline phosphatase activity, DNA, and calcium contents caused by the steroid treatment. The dose of AHZ (10, 30, and 100 mg/kg) significantly increased zinc content in the femoral diaphysis. Present results indicate that the dose of AHZ can prevent the disorder of bone metabolism caused by hydrocortisone treatment. AHZ may have a therapeutic role in the steroid-induced osteopenia.

Segawa Y, Tsuzuike N, Itokazu Y, Tagashira E…
Res Exp Med (Berl) 1992
PMID: 1439196

Zinc-Carnosine Stimulates Bone Formation in Rats

Abstract

Effect of the new zinc compound beta-alanyl-L-histidinato zinc on bone metabolism in elderly rats.

The effect of a new zinc compound beta-alanyl-L-histidinato zinc (AHZ) on bone metabolism was investigated in aged rats (30 weeks old). AHZ (1.0, 2.5 and 7.5 mg/100 g body weight) was orally administered to rats 3 times at 24-hour intervals, and the rats were bled 24 h after the last administration. The administration of AHZ (7.5 mg/100 g) did not cause an appreciable alteration of calcium and inorganic phosphorus concentrations in the serum, and zinc, calcium and deoxyribonucleic acid contents in the femoral diaphysis were significantly increased by the administration of AHZ (7.5 mg/100 g). The bone alkaline phosphatase activity was significantly increased by doses of 1.0-7.5 mg AHZ/100 g. These results suggest that AHZ has a stimulatory effect on bone formation and calcification in aged rats.

Yamaguchi M, Ozaki K
Pharmacology 1990
PMID: 2096395

Zinc Intake and Plasma Level Associated with Bone Density in Men with Osteoporosis

Abstract

Zinc intakes and plasma concentrations in men with osteoporosis: the Rancho Bernardo Study.

Low zinc intakes and reduced blood zinc concentrations have been reported to be associated with osteoporosis in women.
The objective was to examine the independent association between dietary zinc and plasma zinc and the association of each with bone mineral density (BMD) and 4-y bone loss in community-dwelling older men.
Of the original Rancho Bernardo Study subjects, 396 men (age: 45-92 y) completed BMD measurements at baseline in 1988-1992 and 4 y later. Osteoporosis was defined as a BMD > or = 2.5 SDs below the mean for young women (a T-score < or = -2.5). At baseline, dietary intake data were collected by using a standard food-frequency questionnaire, and plasma zinc concentrations were measured by using inductively coupled plasma spectroscopy.
The mean dietary zinc intake was 11.2 mg, and the mean plasma zinc concentration was 12.7 micromol/L. Plasma zinc was correlated with total zinc intake (diet plus supplements). Dietary zinc intake and plasma zinc concentrations were lower in men with osteoporosis at the hip and spine than in men without osteoporosis at those locations. BMDs for the hip, spine, and distal wrist were significantly lower in men in the lowest plasma zinc quartile (<11.3 micromol/L) than in men with higher plasma zinc concentrations. The association between plasma zinc and BMD was cross-sectional, longitudinal, and independent of age or body mass index. However, plasma zinc did not predict bone loss during the 4-y interval.
Dietary zinc intake and plasma zinc each have a positive association with BMD in men.

Hyun TH, Barrett-Connor E, Milne DB
Am. J. Clin. Nutr. Sep 2004
PMID: 15321813 | Free Full Text