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Biomedical subjects

Y Ericsson

Publications and source records attributed to Y Ericsson.

At least 19 recordsLinked to original sources
PubMed1986

Effects of calcium, fluoride and magnesium supplementations on tissue mineralization in calcium- and magnesium-deficient rats.

There is considerable uncertainty about the interrelated effects of calcium (Ca), magnesium (Mg) and fluoride (F) on hypocalcification of the skeleton and Ca accumulation in vital soft tissues. This paper describes experiments with rats fed a diet deficient in Ca and Mg, the latter deficiency being accentuated by a low potassium content. For different groups the drinking water was supplemented with Ca, Mg, F, Ca + F or Mg + F; Ca and F were supplied as chemically compatible compounds. At the end of the 54-d experiment, plasma Ca was strongly reduced in the Ca-deficient groups. Plasma Mg was reduced particularly in the test groups supplied with Ca, without any influence of F supply or varying plasma F. Ca accumulation was much more pronounced in the kidneys than in the heart or aorta, but was mitigated by both Mg and F supplementation. Bone mineralization disturbance due to the dietary imbalance was preventable only by Ca or Ca + F supplementation, and was less in alveolar bone than in femur. However, the Ca supplement was associated with the highest aorta and heart Ca contents, and Ca + F was associated with marked renal Ca accumulation; adequate Mg supply may be essential with Ca + F administration against osteoporosis.

Animals↗
PubMed1983

Fluoride concentrations in rat and human tooth pulps and their possible interference with phosphatase activities.

Alkaline and acid phosphatases (p-ases), fluoride (F), and calcium (Ca) were analyzed in the pulps of rat incisors and young human pre-molars. P-ase activities were about ten times higher in the rat than in the human pulps; in the latter, high p-ase activity appeared to be connected with rapid mineralization. Average total F was 3-4 ng/mg in both rat and human pulp, while Ca showed values several times higher, although greatly varying, in human than in rat pulps. Ionized F was two to three times higher in ultrafiltrates from rat and human pulps than in the blood plasma of the species; in the rat, the F content of the ultrafiltrates increased only three to four times when plasma F was experimentally elevated over 100 times. In vitro, rat pulp alk. p-ase activity was slightly inhibited only in the range above 100 mM NaF, while acid p-ase showed weak inhibition in the region from 0.15-0.25 mM and 40-60% inhibition in the range from 10-100 mM NaF. In vivo, no effect on pulp p-ases was found, even from sublethal NaF doses.

Acid Phosphatase↗
PubMed1980

Studies on the hydrolysis and absorption of monofluorophosphate ions.

Monofluorophosphate (MFP), usually sodium-MFP, Na2PO3F, has become widely used in dentifrices and has been suggested for the treatment of osteoporosis. Its PO3F-- ions are hydrolyzed to F ions and orthophosphate by phosphatases. Experiments on rats showed no such splitting in the stomach, very rapid hydrolysis in the small intestine and the liver, and slower hydrolysis in the blood. In both rats and humans, no evidence of direct absorption of PO3F-- ions into the blood was found. The findings explain the low acute toxicity and the absence of gastric irritation of MFP.

Absorption↗
PubMed1976

Plasma fluoride and enamel fluorosis.

It is postulated that tissue fluid F concentrations are the primary determinants of flouride effects on bones and developing teeth and that these concentrations are dependent on, or mirrored by, blood plasma F. It has earlier been shown that the plasma F levels are dependent on the dietary F supply as well as on skeletal F concentration. Fasting and post-ingestion or postinjection plasma F levels have been determined in rats on F doses that cause different degrees of enamel fluorosis. The results indicate that temporary peak values rather than elevated fasting values are responsible for the occurrence of enamel fluorosis and that the peak values must approach about 10 muM in order to block enamel formation by the ameloblasts. The diagnostic and prognostic importance of plasma F determinations is discussed.

Amelogenesis↗