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Biomedical subjects

C C Kratzing

Publications and source records attributed to C C Kratzing.

8 recordsLinked to original sources

Maturity of fetal lungs tested by production of stable microbubbles in amniotic fluid.

Lung surfactant in amniotic fluid, and hence the maturity of the fetal lungs, can be assessed by observation of stable microbubbles (less than 15 micron diameter). Bubbles are formed by agitation with a Pasteur pipette and examined in hanging drops under the 10 x power of a microscope. Either after a count of bubbles, or after a general survey of hanging drops, the fluid is given a stable microbubble rating. A 'strong' rating indicates that the idiopathic respiratory distress syndrome will not occur after delivery, and that the lecithin/sphingomyelin ratio will indicate maturity. Complete absence of stable microbubbles suggests a high risk of respiratory trouble for the newborn infant, as does a weak or lower rating in the 30 to 37 week gestational age group. The test takes 5 to 10 minutes to perform, is cheap and easy, is not affected by blood, but may be affected by meconium. If a 'strong' rating is found, measurement of the L/S ratio can safely be omitted.

Amniotic Fluid

Factors influencing lipoprotein lipase activity in choline deficiency.

Subcutaneous injections of the lipotropic agent, ethyl trichloracetate, to rats with established choline deficiency raised their plasma triglycerides by 60% and completely removed the hyperglyceridaemic response of Triton WR 1339. The plasma triglyceride levels of choline-supplemented rats were depressed slightly by ethyl trichloracetate administration, which was effective in abolishing response to Triton WR 1339. Lipoprotein lipase activity of epididymal fat pad was stimulated 60% while plasma lipoprotein was not stimulated by ethyl trichloracetate. The increased peripheral removal of low-density lipoprotein-triglyceride complex, allowing greater use to be made of existing apo-proteins, may explain the lipotropic character of the ester.

Adipose Tissue

Extracellular ascorbic acid in lung.

Fifty percent of the ascorbic acid content of sliced rat lung was released from the tissue to the media within a few minutes by either washing or incubating the slices with Krebs-phosphate solution. Measurement of the lactate dehydrogenase and potassium content of the medium after incubating lung slices for 5 min showed that about 20% of the cells were damaged by slicing. Sephadex chromatography of tissue extracts prepared from washed lung slices showed that none of the ascorbic acid in these slices were bound to protein. Also, metabolic poisons were shown to deplete the ascorbic acid content of washed lung slices. Approx. 57% of the lung ascorbic acid of guinea pigs that had been supplemented with ascorbic acid and 78% of the lung ascorbic acid of ascorbic acid-deficient guinea pigs were found in the medium when lung slices from these animals were incubated with Krebs-phosphate solution. These results were taken to indicate the presence of an extracellular pool of ascorbic acid in lung which is maintained even during scurvy.

Animals

Alterations in lipid metabolism produced by ethyl trichloracetate.

Rats maintained on a choline deficient diet and treated with subcutaneous doses of ethyl trichloracetate responded by increasing plasma beta-lipoprotein and plasma triglyceride levels while excess triglyceride was being removed from the liver. There was a transient depression in plasma phospholipid at the beginning of the treatment. Continued administration of ethyl trichloracetate raised plasma triglyceride in choline depleted rats and raised hepatic phospholipid concentration in both choline deficient and supplemented rats. It is suggested that the lipotropic action of ethyl trichloracetate occurs through hepatic triglyceride being removed by the altered plasma lipids and not by inhibition of hepatic triglyceride synthesis.

Animals

Transport of ascorbic acid in perfused rat lung.

Rat lungs were perfused by recycling Krebs-bicarbonate solution in an apparatus which allowed negative pressure ventilation of the lungs. After addition of either reduced or oxidized ascorbic acid to the perfusion fluid serial samples were taken over 60 min and assayed for ascorbic acid. At the end of perfusion, lungs were assayed for ascorbic acid. The results show that reduced ascorbic acid was taken up by the lung and concentrated in the tissue. No appreciable transport of oxidized ascorbic acid was measured.

Animals

Pulmonary edema and ascorbic acid loss.

Loss of ascorbic acid from lung and pulmonary edema were produced in mice by intravenous injection of either adrenaline or noradrenaline (5 mumol/kg). While adrenalectomy performed before noradrenaline administration reduced the degree of pulmonary edema, a prior dose of hexamethonium accentuated this effect. Given alone, hexamethonium caused both loss of ascorbic acid and pulmonary edema. The results show that although endogenous catecholamines can potentiate the pulmonary edema produced by either adrenaline or noradrenaline, they play no specific role in the ascorbic acid loss. The evidence suggests that lung ascorbic acid levels are decreased following the development of pulmonary edema, irrespective of how it was caused.

Adrenal Glands