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B Lonnerdal

Publications and source records attributed to B Lonnerdal.

24 records · Page 2Linked to original sources
PubMed1982

Developmental changes in composition of cats milk: trace elements, minerals, protein, carbohydrate and fat.

The concentrations of iron, copper, zinc, manganese, calcium, magnesium, protein, carbohydrate and fat were analyzed in cats' milk during the course of lactation. Cats' milk is different from most species in that the concentrations of iron, copper, zinc and manganese are lower during the first 2 days of lactation than on days 3-7. After the initial rise in the concentration of these elements, the concentration of iron decreased from 5.9 micrograms/ml to 3.0 micrograms/ml, with most of the decrease occurring between days 8 and 21. Copper concentration declined from 1.6 micrograms/ml to 0.8 microgram/ml, with most of the change occurring between days 8 and 28. Concentration of manganese increased during lactation, from 0.14 microgram/ml of 0.39 microgram/ml. Calcium concentration increased rapidly during the first 3 weeks from 550 micrograms/ml to 1500 micrograms/ml, with little change thereafter. The magnesium concentration (congruent to 100 micrograms/ml) and zinc concentration (congruent 6 micrograms/ml) were not affected by stage of lactation. Protein increased during lactation from 4% to 7%, and fat from 3% to 5%, whereas carbohydrate concentration (congruent 4%) did not change significantly. These data demonstrate that the nutrient intake of the kitten changes markedly during the early neonatal period and that these changes should be taken into account in evaluating studies of suckling cats.

Animals↗
PubMed1981

Seasonal variations and the effects of age on serum copper and zinc values in the dog.

Age-related changes in serum copper and zinc concentrations were evaluated in approximately 800 Beagle dogs. A 20% increase with age was established for both elements. Seasonal variation was also found to have a marked effect on serum zinc with the values positively correlated to ambient temperature. In contrast, serum copper was not affected by temperature. Hemolysis, but not lipemia, was found to affect analytical results.

Age Factors↗
PubMedDate not supplied

Protein and nitrogen composition of equine (Equus caballus) milk during early lactation.

Separation of whey protein from casein in equine milk was achieved by adjustment of pH to 4.3 without addition of calcium, and by ultracentrifugation at 189,000 g for 1 hr. True protein, whey protein, and casein decreased significantly during the first 28 days of lactation with the magnitude of decrease being greatest for whey protein. The proportion of nitrogen in whey protein:casein decreased from 85:15 to 54:46 during the 28 day time period. The concentration of non-protein nitrogen remained relatively constant at 500 mg nitrogen/l but increased in proportion from 2 to 13% of the total nitrogen during the first 28 days of lactation. These results illustrate the unique nitrogen composition of equine milk, which is intermediate between human and ruminant milk, and how it changes during early lactation.

Animals↗
PubMedDate not supplied

Interaction of 125I-labelled ceruloplasmin with human trophoblast cells in vitro.

In vitro binding, internalization and release of the plasma protein ceruloplasmin was investigated using primary cultures of human placental trophoblast cells. Binding of 125I-labelled ceruloplasmin at 4 degrees C reached equilibrium by 5-6 h; binding was linear throughout all concentrations tested (1 nM-3.3 microM). Addition of greater than 5-10 microM unlabelled ceruloplasmin or a variety of other proteins (albumin, transferrin, IgG) were equally effective in displacing bound ceruloplasmin in a concentration-dependent manner. When cells were incubated at 37 degrees C, the majority of surface-bound 125I-labelled ceruloplasmin was released directly to the extracellular medium. Trypsin-resistant radioactivity increased to 18 per cent of initially bound ceruloplasmin within 1 min, declining to 5 per cent by 2 h. The acquisition of trypsin-resistant radioactivity was unaffected by the addition of a variety of metabolic inhibitors and no evidence of intracellular degradation of ceruloplasmin was found. In summary, our results suggest that the majority of ceruloplasmin binding to trophoblast cells is nonspecific, of low affinity, and easily dissociable at 4 degrees C. Only a small amount of ceruloplasmin appeared to be internalized, by an as yet unknown mechanism.

Ammonium Chloride↗