Relationship between vitamin D status and deposition of bound calcium in skeletal muscle of the rat

Our previous work has shown that feeding 5 million international units (IU) of vitamin D3 to beef steers can produce tender strip loin and top round steaks. Our current experiment was designed to determine whether feeding two metabolites of vitamin D3, 25-hydroxyvitamin D3, and 1,25-dihysroxyvitamin D3, produces tender strip loin, top round, and top blade steaks more effectively than does supplemental vitamin D3 without leaving a substantial amount of residual vitamin D3 in muscle. Thirty-three continental crossbred steers were randomly allotted to one of four treatment groups. The first group was fed a placebo. The second group received 5 million IU of vitamin D3 each day for nine days and was slaughtered two days later. The third group received one dose of 125 mg of 25-hydroxyvitamin D3 four days before harvest, and the fourth group received one dose of 500 mg of 1,25-dihydroxyvitamin D3 three days before harvest. Blood samples were collected before treatment and at the time of slaughter for subsequent analysis of calcium, vitamin D3, 25-hydroxyvitamin D3, and 1,25-dihydroxyvitamin D3 concentrations in plasma. Steaks from the longissimus lumborum (strip loin) and semimembranous (top round) muscles were collected from each animal and aged for 8, 14, and 21 days, and steaks from the infraspinatus were collected and aged for 14 and 21 days. All steaks were analyzed for tenderness by Warner-Bratzler shear force determination. Concentrations of vitamin D3 in plasma were higher in vitamin D3-treated cattle (P < 0.0001). Concentrations of plasma 25-hydroxyvitamin D3 were increased in 25-hydroxyvitamin D3-treated cattle, but not as high as vitamin D3-treated cattle (P < 0.0001). 1,25-Dihydroxyvitamin D3 concentrations were higher in 1,25-dihydroxyvitamin D3-treated animals compared with all treatments (P < 0.0001). Supplementing steers with vitamin D3 increased the concentration of vitamin D3 and 25-hydroxyvitamin D3 in the meat of all muscles sampled (P < 0.0001). Supplementing steers with 25-hydroxyvitamin D3 increased the concentration of 25-hydroxyvitamin D3 in meat, but to an amount less than half that of cattle treated with vitamin D3. Warner-Bratzler shear force analysis showed that feeding 1,25-dihydroxyvitamin D3 did not significantly lower shear force values, but supplemental vitamin D3 and 25-hydroxyvitamin D3 produced longissimus lumborum and semimembranous steaks with lower shear force values (P < 0.06). Analysis of Western blots showed that longissimus lumborum and semimembranous steaks from cattle fed supplemental vitamin D3 and 25-hydroxyvitamin D3 (but not steaks from cattle fed 1,25-dihydroxyvitamin D3), had greater proteolysis of troponin T to a 30 kDa component.

Section: Effects Of Supplemental Vitamin D 3 25-hydroxyvitamin D 3 mentioning

confidence: 94%

The use of vitamin D3 and its metabolites to improve beef tenderness1

Foote

Horst

Huff-Lonergan

et al. 2004

“…Skeletal muscle is an important target organ for vitamin D 3 (de Boland and Nemere, 1992;Boland et al, 1995). Toury et al (1990) showed that vitamin D supplementation to rats increased bound calcium at the Z-line and increased cytosolic skeletal muscle calcium. Indeed, Swanek et al (1999) found higher calcium concentrations in plasma and in longissimus muscle from steers fed diets containing vitamin D. Also, loin steaks from steers fed vitamin D were more tender.…”

Section: Introductionmentioning

confidence: 99%

The use of vitamin D3 to improve beef tenderness.

Montgomery

Parrish

Beitz

et al. 2000

An experiment was designed to test the hypothesis that short-term oral administration of dietary vitamin D3 to beef cattle before slaughter would increase beef tenderness through greater calcium-activated calpain activity in postmortem aged skeletal muscle. Thirty continental crossbred steers were allotted randomly to three treatment groups housed in one pen. One group served as a control; two other groups were administered boluses with either 5 x 10(6) or 7.5 x 10(6) IU of vitamin D3 daily for 9 d. Cattle were slaughtered 1 d later. The longissimus lumborum was excised from each carcass 72 h postmortem and steaks removed at 3, 7, 14, and 21 d postmortem. The semimembranosus muscle (top round) was excised from each carcass 72 h postmortem and steaks removed at 7, 14, and 21 d postmortem. Blood plasma calcium concentration of cattle treated with 5 or 7.5 x 10(6) IU of vitamin D3 was higher (P < .05) than that of controls. Strip loin and top loin steaks from cattle fed supplemental doses of vitamin D3 had lower (P < .05) Warner-Bratzler (W-B) shear values at 14 d postmortem but were not significantly different from controls at 3, 7, or 21 d (strip loins) or 7 or 21 d (top rounds). No significant difference in strip loin steak tenderness was observed by sensory panel at 14 d postmortem (P < .17) between steaks from control and vitamin D3-treated steers. At 14 d postmortem, strip loin and top round steaks from cattle fed 5 x 10(6) IU of vitamin D3, but not from those given 7.5 x 10(6) IU, showed more proteolysis (P < .05) than did steaks from control cattle, based on Western blotting analysis. Therefore, the use of supplemental dietary vitamin D3 given daily for 9 d before slaughter did improve tenderness (lower W-B shear values) of 14-d postmortem aged beef. Increased proteolysis seems to be the mechanism of tenderization.

“…The effect of supplementing diets of feedlot steers with 0, 0.5, 1.0, or 5.0 million IU/(steerؒd) of vitamin D 3 for eight consecutive days before slaughter and postmortem aging on the magnesium content of homogenate and subcellular fractions of LM (g of Mg/mg of protein) Within a row and ageing duration, least squares means that do not have a common superscript letter differ (P < 0.05); n = 6 per mean. Toury et al (1990) demonstrated that repletion of VITD-deficient rats doubled Ca concentrations in the cytosol of skeletal muscle. Results of the current study demonstrated that VITD supplementation could increase free Ca by 2.6-fold at 3 d postmortem, with a 6fold increase at 21 d postmortem.…”

Section: Resultsmentioning

confidence: 99%

“…Samples were then strained through a metal strainer (approximately 1mm pore size) and differentially centrifuged to separate specific fractions. Nuclei, cell debris, and large fragments of the myofibrils were removed by centrifugation at 1,500 × g, small myofibril fragments were sedimented at 3,000 × g, mitochondria at 8,000 × g, and sarcoplasmic reticulum at 180,000 × g, as described by Toury et al (1990). Each centrifugation tube was rinsed and vortexed twice with 10 mL of 0.25 M sucrose for removal of sedimentary cellular proteins.…”

Section: Muscle Fractionationmentioning

confidence: 99%

“…Electron microscopy studies and electrophoretic measurements have demonstrated that VITD deficiency results in degenerative muscle, with a loss of troponin-C and actin (George et al, 1981;de Boland et al, 1983). Toury et al (1990) reported that vitamin D repletion of rats increased the concentration of bound Ca to the myofibril and free cytosolic concentrations of Ca and P. This increase in free cytosolic Ca could have stimulated Ca-activated calpains and could be responsible for muscle structural alterations. Thus, muscle weakness from VITD deficiency could be explained by increases in muscle Ca.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of supplemental vitamin D3 concentration on concentrations of calcium, phosphorus, and magnesium relative to protein in subcellular components of the longissimus and the distribution of calcium within longissimus muscle of beef steers12

Montgomery

Blanton

Horst

et al. 2004

The effect of supplementing diets with various levels of vitamin D3 to provide 0, 0.5, 1, and 5 million IU/(steer x d) for 8 d before slaughter on the mineral content and localization of Ca in LM and muscle fragments was studied during the postmortem aging process. Twelve feedlot steers of three biological types were given access to the four levels of vitamin D for 8 d before slaughter. Differential centrifugation techniques were used to determine the concentrations of minerals relative to protein in different muscle fragments on d 3 and 21 postmortem. Electron microscopy visualization of bound Ca indicated that vitamin D3 mobilized Ca from the sarcoplasmic reticulum and transverse tubule system into the myofibrils. Bound Ca was concentrated near the Z-line at the A-band/I-band juncture within the sarcomere. Supplementing steers with 1 and 5 million IU/(steer x d) of vitamin D3 increased (P < 0.05) Ca, P, and Mg concentrations per unit of protein in the cytosol. Soluble cytosolic Ca concentrations were greater (P < 0.05) on d 21 than on d 3 postmortem only when steers were supplemented with 5 million IU/d. Concentrations of Ca, P, and Mg in isolated tissues were increased (P < 0.05) in nuclei and myofibrilar proteins by supplementing steers with 1 and 5 million IU/ (steer x d) of vitamin D3. All supplemental vitamin D3 treatments also increased (P < 0.001) Mg concentrations in the cytosol, regardless of aging treatment, and increased Mg concentrations (P < 0.04) within the mitochondria at d 3 postmortem. Thus, supplementation of feedlot steers with vitamin D3 at levels of 0.5 to 5 million IU/(steer x d) increased Ca concentrations within respiring muscle, resulting in increased bound tissue Ca concentrations. When the respiring muscle was converted to meat, the increased bound tissue Ca resulting from vitamin D3 treatment released Ca concentrations into the cytosol during aging (P < 0.05). Results of this study indicate that vitamin D3 supplementation increased total cytosolic Ca, P, and Mg concentrations in meat.