Sachchidananda Banerjee

The transport of tetracyclines across the mouse ileum in vitro: the effect of cations and other agents

The intestinal transfer of different tetracyclines dissolved in calcium‐and magnesium‐free Krebs bicarbonate buffer solution, pH 7·4, was studied using the everted ileum of the mouse. The rates of transfer of chlortetracycline and demethylchlortetracycline were less than those of tetracycline and oxytetracycline, the latter compounds being transferred at the same rate. Addition of calcium and magnesium to the buffer greatly reduced the transfer of tetracycline; this inhibition could be antagonized by EDTA. The presence of iron also inhibited the transfer of tetracycline. The inhibitory effect of these ions on tetracycline transfer seemed due to chelation of the drug. Glucosamine and acetylmethionine, but not acetyl glucosamine, diminished the intestinal transfer of tetracyclines. The former two agents did not influence the uptake of tissue fluids. Tetracycline was also transferred from the serous to the mucous coat in the non‐everted intestinal sac of mice. The above observations suggested that the absorption of tetracyclines was not due solely to passive diffusion.

Effect of Diabetogenic Hormones on Transport of Glucose in Small Intestine in vitro

Summary Intestinal transport of glucose in vitro was studied in rats treated with ad-renocorticotropic hormone, hydrocortisone, desoxycorticosterone, thyroid powder and methyl thiouracil by use of everted small intestine sac technique. The concentration of glucose in the medium was 0.3%. ACTH, hydrocortisone and desoxycorticosterone treatments increased significantly the intestinal absorption of glucose. The thyroid hormone did not influence intestinal absorption of glucose in rats.

Hexosamine and hydroxyproline contents of tissues in scurvy.

Summary The hexosamine and hydroxyproline contents of aorta, lung, skin, kidney, skeletal muscle, bone and cartilage were determined in normal, scorbutic and insulintreated scorbutic guinea pigs. In the scorbutic guinea pigs hexosamine content significantly increased in aorta, kidney, skeletal muscle and bone and no change was observed in lung, liver, cartilage and skin. Insulin treatment had no effect on these contents. Hydroxyproline content decreased significantly only in kidney and cartilage of scorbutic guinea pigs. Prolonged insulin treatment of the scorbutic animals produced a significant increase in the hydroxyproline contents of cartilage, kidney, lung and skin. The possible implications of the results have been discussed.

Effect of feeding glucoascorbic acid to white rats, chicks and guinea pigs.

Summary Rats fed a synthetic diet containing 10% glucoascorbic acid lose weight and develop severe diarrhea. Similar but less severe symptoms develop when 10% ascorbic acid is used. Post-mortem examination revealed no hemorrhages in any part of the body. Animals receiving 2% liver powder in addition to either 10% glucoascorbic acid or ascorbic acid grew as well as normal animals although they showed moderate diarrhea. Glucoascorbic acid at levels of 5, 1 and 0.5% had no effect on the growth of rats but the 5 and 1% levels produced diarrhea. Chicks fed a synthetic ration containing 10% glucoascorbic acid and 2% solubilized liver showed no deleterious effects. The severe diarrhea and loss of weight in guinea pigs fed a natural diet containing 10% glucoascorbic acid could not be prevented by the addition of 10% ascorbic acid but was prevented by the addition of 6% 1:20 liver powder.

Biochemical and Histochemical Changes in Aorta of Chicks Fed Vegetable Oils and Cholesterol

Summary Portions of aorta of chicks fed coconut oil, sesame oil, mustard oil and hydrogenated groundnut oil, with or without simultaneous administration of cholesterol, for 8 weeks were analyzed for cholesterol, phospholipids, hexosamine and hydroxyproline. The distribution of elastic tissue, acid mucopolysaccharides and lipids in the aorta was also studied by histochemical methods. Feeding of cholesterol with or without oils increased cholesterol and phospholipids in different portions of aorta. Oils when fed alone increased the phospholipids without changing the cholesterol of the aorta. Hexosamine content of the aorta diminished when vegetable oils other than sesame oil were fed either alone or in combination with cholesterol. This indicated a decrease in mucopolysaccharide content of the aorta, Hydroxyproline of aorta increased when chicks were fed vegetable oils with cholesterol. The increase in arterial collagen, as evidenced by its hydroxyproline content, appeared to be proportional to the degree of hypercholesteremia, Feeding of oils with cholesterol increased lipid and acid mucopolysaccharide contents of the aorta, proliferation of the intima, and fragmentation or complete disappearance of the elastic tissue in the intima and media. The changes were most marked in the arch of aorta. Elastic tissue changes coupled with disturbances in the metabolism of mucopolysaccharides and collagen might alter the permeability of the arterial wall resulting in atheroma formation. The severity or degree of the different changes was neither related to the plasma level of cholesterol nor to the saturation or unsaturation of the vegetable oils used.

Effect of Oxytetracycline and Tetracycline on Glucose Tolerance and Serum Lipids

Summary Oxytetracycline or tetracycline, 10 mg/kg, was administered for 10 consecutive days to rabbits and rhesus monkeys. Glucose tolerance test was performed and different fractions of serum lipids were estimated in these animals before and after treatment with the antibiotics to find if their prolonged use interfered with carbohydrate and lipid metabolism. Both antibiotics diminished glucose tolerance. The pattern of serum lipids was changed. There were increases in the serum triglycerides, phospho-lipids, β-lipoprotein cholesterol and free fatty acids in most of the animals after treatment with the antibiotics. Tetracyclines should be used with caution due to the metabolic disturbances they might produce.

Certain Aspects of Protein Metabolism in Hypercholesteremic Chickens

Summary Glutamic-oxaloacetic-transaminase (GOT) and glutamic-pyruvic-transaminase (GPT) of serum, aorta and liver and free amino acid composition of the serum and aorta were determined in normal and hypercholesteremic-atherosclerotic chickens. GOT and GPT of serum and GOT of liver increased with the onset of atherosclerosis suggesting an overall increase in the rate of transamination reaction in the body. The activities of the arterial transaminases did not change appreciably. Concentrations of most of the free amino acids increased in the serum and diminished in the aorta of hyper-cholesteremic-atherosclerotic chickens. Chemical changes accompany the morphological alterations during the progress of atherosclerosis.

Effect of Hypoinsulinfsm on Intracellular Transport of Glucose in the Small Intestine

Summary Effect of insulin insufficiency on the transport of glucose in the intestinal cells was studied by incubation of small intestines of rats and guinea pigs in a medium containing glucose. Insulin deficiency was produced by injection of alloxan to rats and by feeding a scorbutogenic diet to guinea pigs. Concentrations of glucose in the intra-cellular water of the intestine incubated in glucose-saline were found higher in the intestines obtained from diabetic rats and from scorbutic guinea pigs as compared to normal. Insulin does not seem to have any direct role in the intracellular transport of glucose in the small intestine. The Council of Scientific and Industrial Research, New Delhi, rendered financial assistance for the investigation.

Effect of Scurvy on Serum Proteins of Rhesus Monkeys.

Summary Serum total proteins, glycopro-teins, mucoproteins, albumin and different fractions of globulins were determined in normal monkeys fed ad lib, in scorbutic monkeys, in normal monkeys pair-fed with the scorbutic, and in monkeys which recovered from scurvy after treatment with ascorbic acid. Following changes from pair-fed normal were observed in scorbutic monkeys: Serum total proteins, a2-globulin and γ-globulin did not change. Serum albumin diminished. Glycoproteins, mucoproteins, a1-globulin and β-globulin expressed as percent of total protein of serum increased. The changes in serum proteins were reversed to normal when the scorbutic monkeys recovered after supplementation with ascorbic acid with the exception of serum a2-globulin which diminished significantly. The changes in serum proteins of scorbutic monkeys seems to be a specific effect of ascorbic acid deficiency.

Carbohydrate and Lipid Metabolism in Animals Treated with Pyrrolidinomethyl Tetracycline

Summary Pyrrolidinomethyl tetracycline was administered to rats, rabbits, and monkeys for 10 days and changes in the utilization of glucose and distribution of lipids in the tissues were studied. Treated animals showed diminished glucose tolerance. They had decreased glycogen and increased cholesterol and total lipids in the liver. There was a rise in plasma levels of lipids such as cholesterol, phospholipids, triglycerides and free fatty acids. Changes indicated impaired metabolism of carbohydrate and lipids. Tetracycline moiety of the antibiotic seemed responsible for the changes observed. The drug should be used with caution as its therapeutic effect might disturb the normal metabolic patterns in the body.