Research focus: The role of nutrients in early growth and development and the physiological roles of quinone cofactors derived from tyrosine, such as pyrroloquinoline quinone. Selected past honors and activities: Past President, American Society for Nutrition, Fellow - AAAS and ASN. Address: Davis, California, United States
The roles for trace minerals in soft and hard tissue matrix development and maintenance have been... more The roles for trace minerals in soft and hard tissue matrix development and maintenance have been investigated only in a limited and selected fashion. For example, it is known that Cu deprivation can influence markedly the structural integrity of collagen and elastin matrices by causing reduced crosslinking (1). It is also known that Zn deprivation may cause changes in the composition of basal laminae or influence the functional activity and distribution of cell surface proteins (2–5). Further, Mn deprivation can influence proteoglycan or structural glycoprotein deposition (1). These examples are important in that it is now clear that most of the abnormal morphogenetic effects of matrix molecules are associated with alteration of their physical properties or at cell surfaces (6).
Elastin is one of the primary structural components of arterial vessels. In its mature form, this... more Elastin is one of the primary structural components of arterial vessels. In its mature form, this protein is highly crosslinked and insoluble in most solvents (Partridge, 1962). Soluble fractions (α and β-elastins) of insoluble elastin may be prepared, however, by mild hydrolysis (Partridge, et al., 1955). Native soluble elastins have also been obtained after blocking the formation of crosslinks in vivo (Rucker et al., 1972, 1973; Sandberg et al., 1969; Smith et al., 1972). Native soluble elastin, often referred to as tropoelastin, is the precursor to insoluble elastin. The insoluble protein is associated with mucopolysacharide, lipid, collagen, microfibrillar and other protein in the form of elastin fibers (Ross, 1973; Ross and Bornstein, 1970).
... CARSTEN R. SMIDT,* CLIFFORD J. UNKEFER,~ DAVID R. HOUCK,~" AND ROBERT €3. RUCKER*'~... more ... CARSTEN R. SMIDT,* CLIFFORD J. UNKEFER,~ DAVID R. HOUCK,~" AND ROBERT €3. RUCKER*'~ Department of Nutrition,* University of California, Davis ... The intes-tine was divided into three parts (duodenum, jejunum, and ileum), each of which was washed with saline ...
Day-old White Leghorn cockerels were fed skim-milk-based diets containing 0, 2, 4, 8, or 16 ppm a... more Day-old White Leghorn cockerels were fed skim-milk-based diets containing 0, 2, 4, 8, or 16 ppm added copper as CuSO4 for 21 days. Lysyl oxidase was extracted from bone and tendon. The recovery of activity from the extracts was linearly correlated with dietary copper (r greater than 0.90). Tests of the mechanical properties of tendon and bone indicated that tendon viscoelasticity (as measured by stress--relaxation) may not be significantly influenced by copper, whereas the ultimate torsional strength of bone is markedly decreased when the dietary copper level is below 1 ppm. Furthermore the torsional fracture characteristics of bone from copper-deficient birds demonstrated a lack of plastic deformation prior to failure that was normally seen in bone from control birds. The change in the mechanical properties of bone from copper-deficient birds appeared to be related to a decrease in the amounts of dihydroxylysinonorleucine and other lysine-derived cross-linking amino acids in bone collagen. The data indicate that the requirement for optimal growth of chicks fed skim-milk-based diets is 6--8 ppm copper, however, the requirement for normal cross-link formation in bone is less than 2 ppm copper.
ABSTRACT Pyrroloquinoline quinone (PQQ) functions as a cofactor for prokaryotic oxidoreductases, ... more ABSTRACT Pyrroloquinoline quinone (PQQ) functions as a cofactor for prokaryotic oxidoreductases, such as methanol dehydrogenase and membrane-bound glucose dehydrogenase. In animals fed chemically defined diets, PQQ improves reproductive outcome and neonatal growth. Consequently, the present study was undertaken to determine the extent to which PQQ is absorbed by the intestine, its tissue distribution, and route of excretion. About 28 micrograms of PQQ (0.42 microCi/mumol), labeled with 14C derived from L-tyrosine, was administered orally to Swiss-Webster mice (18-20 g) to estimate absorption. PQQ was readily absorbed (62%, range 19-89%) in the lower intestine, and was excreted by the kidneys (81% of the absorbed dose) within 24 hr. The only tissues that retained significant amounts of [14C]PQQ at 24 hr were skin and kidney. For kidney, it was assumed that retention of [14C]PQQ represented primarily PQQ destined for excretion. For skin, the concentration of [14C]PQQ increased from 0.3% of the absorbed dose at 6 hr to 1.3% at 24 hr. Furthermore, most of the [14C]PQQ in blood (greater than 95%) was associated with the blood cell fraction, rather than plasma.
White Leghorn cockerols were fed a semipurified diet (containing fluoride at 0 to 800 ppm) from t... more White Leghorn cockerols were fed a semipurified diet (containing fluoride at 0 to 800 ppm) from the day of hatching. The birds were also injected daily with solutions containing ethane-1-hydroxy-1,1-diphosphonate (EHDP) at concentrations ranging from 5 to 20 mg as phosphorus/kg of body weight in isotonic saline. Changes in bone mineral compositions and plasma Ca, Mg and F were determined
... RB Rucker, D. Ford, W. Goettlich Riemann and K. Tom Department of Nutrition, University of Ca... more ... RB Rucker, D. Ford, W. Goettlich Riemann and K. Tom Department of Nutrition, University of California, Davis Received June 25, accepted October 14, 1973 ... In methanol-H20 mixtures calcium binding appeared to be independent of changes in pit and ionic strength. ...
The roles for trace minerals in soft and hard tissue matrix development and maintenance have been... more The roles for trace minerals in soft and hard tissue matrix development and maintenance have been investigated only in a limited and selected fashion. For example, it is known that Cu deprivation can influence markedly the structural integrity of collagen and elastin matrices by causing reduced crosslinking (1). It is also known that Zn deprivation may cause changes in the composition of basal laminae or influence the functional activity and distribution of cell surface proteins (2–5). Further, Mn deprivation can influence proteoglycan or structural glycoprotein deposition (1). These examples are important in that it is now clear that most of the abnormal morphogenetic effects of matrix molecules are associated with alteration of their physical properties or at cell surfaces (6).
Elastin is one of the primary structural components of arterial vessels. In its mature form, this... more Elastin is one of the primary structural components of arterial vessels. In its mature form, this protein is highly crosslinked and insoluble in most solvents (Partridge, 1962). Soluble fractions (α and β-elastins) of insoluble elastin may be prepared, however, by mild hydrolysis (Partridge, et al., 1955). Native soluble elastins have also been obtained after blocking the formation of crosslinks in vivo (Rucker et al., 1972, 1973; Sandberg et al., 1969; Smith et al., 1972). Native soluble elastin, often referred to as tropoelastin, is the precursor to insoluble elastin. The insoluble protein is associated with mucopolysacharide, lipid, collagen, microfibrillar and other protein in the form of elastin fibers (Ross, 1973; Ross and Bornstein, 1970).
... CARSTEN R. SMIDT,* CLIFFORD J. UNKEFER,~ DAVID R. HOUCK,~" AND ROBERT €3. RUCKER*'~... more ... CARSTEN R. SMIDT,* CLIFFORD J. UNKEFER,~ DAVID R. HOUCK,~" AND ROBERT €3. RUCKER*'~ Department of Nutrition,* University of California, Davis ... The intes-tine was divided into three parts (duodenum, jejunum, and ileum), each of which was washed with saline ...
Day-old White Leghorn cockerels were fed skim-milk-based diets containing 0, 2, 4, 8, or 16 ppm a... more Day-old White Leghorn cockerels were fed skim-milk-based diets containing 0, 2, 4, 8, or 16 ppm added copper as CuSO4 for 21 days. Lysyl oxidase was extracted from bone and tendon. The recovery of activity from the extracts was linearly correlated with dietary copper (r greater than 0.90). Tests of the mechanical properties of tendon and bone indicated that tendon viscoelasticity (as measured by stress--relaxation) may not be significantly influenced by copper, whereas the ultimate torsional strength of bone is markedly decreased when the dietary copper level is below 1 ppm. Furthermore the torsional fracture characteristics of bone from copper-deficient birds demonstrated a lack of plastic deformation prior to failure that was normally seen in bone from control birds. The change in the mechanical properties of bone from copper-deficient birds appeared to be related to a decrease in the amounts of dihydroxylysinonorleucine and other lysine-derived cross-linking amino acids in bone collagen. The data indicate that the requirement for optimal growth of chicks fed skim-milk-based diets is 6--8 ppm copper, however, the requirement for normal cross-link formation in bone is less than 2 ppm copper.
ABSTRACT Pyrroloquinoline quinone (PQQ) functions as a cofactor for prokaryotic oxidoreductases, ... more ABSTRACT Pyrroloquinoline quinone (PQQ) functions as a cofactor for prokaryotic oxidoreductases, such as methanol dehydrogenase and membrane-bound glucose dehydrogenase. In animals fed chemically defined diets, PQQ improves reproductive outcome and neonatal growth. Consequently, the present study was undertaken to determine the extent to which PQQ is absorbed by the intestine, its tissue distribution, and route of excretion. About 28 micrograms of PQQ (0.42 microCi/mumol), labeled with 14C derived from L-tyrosine, was administered orally to Swiss-Webster mice (18-20 g) to estimate absorption. PQQ was readily absorbed (62%, range 19-89%) in the lower intestine, and was excreted by the kidneys (81% of the absorbed dose) within 24 hr. The only tissues that retained significant amounts of [14C]PQQ at 24 hr were skin and kidney. For kidney, it was assumed that retention of [14C]PQQ represented primarily PQQ destined for excretion. For skin, the concentration of [14C]PQQ increased from 0.3% of the absorbed dose at 6 hr to 1.3% at 24 hr. Furthermore, most of the [14C]PQQ in blood (greater than 95%) was associated with the blood cell fraction, rather than plasma.
White Leghorn cockerols were fed a semipurified diet (containing fluoride at 0 to 800 ppm) from t... more White Leghorn cockerols were fed a semipurified diet (containing fluoride at 0 to 800 ppm) from the day of hatching. The birds were also injected daily with solutions containing ethane-1-hydroxy-1,1-diphosphonate (EHDP) at concentrations ranging from 5 to 20 mg as phosphorus/kg of body weight in isotonic saline. Changes in bone mineral compositions and plasma Ca, Mg and F were determined
... RB Rucker, D. Ford, W. Goettlich Riemann and K. Tom Department of Nutrition, University of Ca... more ... RB Rucker, D. Ford, W. Goettlich Riemann and K. Tom Department of Nutrition, University of California, Davis Received June 25, accepted October 14, 1973 ... In methanol-H20 mixtures calcium binding appeared to be independent of changes in pit and ionic strength. ...
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Papers by Robert Rucker