Eur J Cancer Clin Oncol. 1987 Jul;23(7):973-7.
Tetracycline in the treatment of malignant effusions: evidence for a cytostatic action of the decomposed drug.

Sauter C, Cogoli M.

Department of Medicine, University Hospital, Zurich, Switzerland.

During the in vitro growth of human carcinoma cell lines an inhibition of cell growth in media containing tetracycline was observed at a concentration which was about 1000 times below the one reached in the pleural fluid of malignant effusions after tetracycline instillation. During short time drug-cell contact only previously heated tetracycline showed growth inhibition like doxorubicin, a substance of similar structure and origin. Freshly prepared tetracycline inhibited cell growth only after several minutes of drug cell contact. Our observations in vitro suggest that decomposed tetracycline plays an important role in the control of malignant effusions.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3666001&dopt=Abstract antibiotics, tetracycline




Vopr Pitan. 1976 May-Jun;(1):59-60.
[Effect of culinary treatment on residual quantities of streptomycin and oxytetracycline in meat and chicken by-products]

[Article in Russian]

Shakarian GA, Akopian ZM, Sevian TK.

The effect of different methods of culinary treatment on the residual amounts of streptomycin and oxytetracycline in the meat and edible viscera (liver, muscle stomach) of egg-layer hens and in the eggs was clarified. Under the effect of heat treatment (cooking, frying, autoclaving) the amount of streptomycin and oxytetracycline in the meat and edible viscera of chicken was found to gradually decrease by comparison with the initial one, with oxytetracycline declining more intensively. In the chicken meat oxytetracycline becomes completely disintegrated after 2 hours of cooking, while amounts of streptomycin in the chicken liver are also much greater than those of oxytetracycline, whereas in the muscle stomach after 2-hour long cooking, in cooked and fried eggs, where oxytetracycline becomes fully disintegrated, certain amounts of streptomycin still continue to be present.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=987647&dopt=Abstract antibiotics, tetracycline




Arch Ophthalmol. 1987 Feb;105(2):268-71.
Systemic tetracycline treatment of alkali-induced corneal ulceration in rabbits.

Seedor JA, Perry HD, McNamara TF, Golub LM, Buxton DF, Guthrie DS.

Recent evidence has demonstrated a marked anticollagenolytic effect for the tetracycline antibiotics. We have examined the efficacy of systemic tetracycline hydrochloride in a rabbit model of corneal ulceration. A standard alkali burn (1N sodium hydroxide for 40 s) was delivered to 62 eyes (31 rabbits). Animals were then divided into three groups: group 1 (controls) (ten rabbits [20 eyes]) received no treatment; group 2 (ten rabbits [20 eyes]) received 10 mg/kg/d of tetracycline hydrochloride, given intramuscularly; and group 3 (11 rabbits [22 eyes]) received 50 mg/kg/d. Ulceration occurred in 85% (17/20) of control eyes. The higher dosage of tetracycline was more effective in preventing ulceration than the lower dosage (9.1% vs 55%). Eyes with higher levels of tetracycline in ocular tissues were less likely to ulcerate.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3813962&dopt=Abstract antibiotics, tetracycline




Am J Vet Res. 2002 Apr;63(4):491-4.
Influence of long-term treatment with tetracycline and niacinamide on antibody production in dogs with discoid lupus erythematosus.

Mueller RS, Fieseler KV, Bettenay SV, Rosychuk RA.

Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.

OBJECTIVE: To evaluate the effect of long-term treatment with tetracycline and niacinamide on antibody production in dogs by measuring postvaccinal serum concentrations of antibodies against canine parvovirus and canine distemper virus. ANIMALS: 10 dogs receiving long-term treatment with tetracycline and niacinamide (treatment group) and 10 healthy dogs (control group). PROCEDURE: The treatment group included 9 dogs with discoid lupus erythematosus and 1 dog with pemphigus foliaceus on long-term treatment (> 12 months) with tetracycline and niacinamide. The control group included 10 healthy dogs with no clinical signs of disease and no administered medications for the past 3 months. Blood samples were obtained from all dogs by jugular venipuncture. Serum antibody titers against canine parvovirus and canine distemper virus antigens were measured, using hemaglutination inhibition and serum neutralization, respectively, and compared between groups. RESULTS: A significant difference in antibody titers between treatment- and control-group dogs was not found. All dogs had protective antibody titers against canine distemper virus, and 8 of 10 dogs from each group had protective titers against canine parvovirus infection. CONCLUSION AND CLINICAL RELEVANCE: These results provide evidence that long-term treatment with tetracycline and niacinamide does not interfere with routine vaccinations and thus does not seem to influence antibody production in dogs.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11939308&dopt=Abstract antibiotics, tetracycline




Chest. 1993 Apr;103(4):1113-7.
Tetracycline and doxycycline inhibit pleural fluid metalloproteinases. A possible mechanism for chemical pleurodesis.

Hurewitz AN, Wu CL, Mancuso P, Zucker S.

Medical Service, Northport Veterans Administration Center, NY.

We hypothesized that inhibition of matrix-degrading metalloproteinases (MMPs) accounts for a portion of the pleural fibrosis and adhesions of tetracycline pleurodesis. MMPs recently have been described in pleural fluid from patients with both exudative and transudative effusions. Since tetracyclines are recognized inhibitors of other metalloproteinases, we investigated their inhibitory capacity in pleural fluid. High concentrations of several different tetracyclines reduced MMP activity of pleural fluid by more than 75 percent. Lower concentrations (< or = 1 mg/ml) had only modest inhibitory effects. High concentration of of tetracyclines also inhibited cell synthesis of MMPs, in vitro, but other measures of vital cell function were also impaired. We conclude that tetracyclines are effective inhibitors of MMP activity in pleural fluid and may also reduce synthesis of MMPs via non specific cell injury. These data suggest a possible mechanism to account for tetracycline pleurodesis; ie, an inhibition of MMP activity in pleural fluid.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8131449&dopt=Abstract antibiotics, tetracycline




Pharmazie. 1977 Aug-Sep;32(8-9):519-22.
Effect of magnesium trisilicate and citric acid on the biovailability of tetracycline in man.

Khalil SA, Daabis NA, Naggar VF, Wafik M.

Oral absorption of tetracycline hydrochloride by human subjects was compared with its absorption when coadministered with magnesium trisilicate, citric acid or magnesium trisilicate-citric acid mixture. Evaluation of the absorption rate was done by means of urinary excretion measurements. The concomitant administration of magnesium trisilicate with tetracycline hydrochloride resulted in a dramatic reduction of the excretion rate of the drug. Ingestion of citric acid with tetracycline showed no significant effect on its absorption. Citric acid administration simultaneously with tetracycline hydrocloride-magnesium trisilicate combination failed to improve the absorption of tetracycline in the presence of magnesium trisilicate contrarily to preveious in vitro results. Conclusions were made that in vitro experiments are not always successful in the prediction of in vivo findings.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=201941&dopt=Abstract antibiotics, tetracycline




Eur J Biochem. 1986 Dec 15;161(3):723-6.
Tetracycline can inhibit tRNA binding to the ribosomal P site as well as to the A site.

Geigenmuller U, Nierhaus KH.

A and P sites of Escherichia coli ribosomes were titrated with AcPhe-tRNAPhe, in the absence or presence of tetracycline. The P-site location of the bound AcPhe-tRNA was assessed by means of a quantitative puromycin reaction. The results demonstrate that, in agreement with the generally held view, tetracycline exclusively inhibits the A-site binding, if the statistical number of bound acyl-tRNA molecules per ribosome does not exceed about 0.5. However, above this value the P site becomes sensitive to tetracycline as well. It follows that the tightly coupled 70S ribosomes used in functional studies appear to be functionally heterogeneous, i.e. those P sites which cannot be affected by tetracycline are preferentially occupied by AcPhe-tRNA, whereas higher concentrations of this tRNA species are required to fill tetracycline-sensitive P sites. Furthermore, the results imply that under tRNA saturation conditions the tetracycline inhibition cannot be used as an indicator for the site location of bound tRNA.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3641718&dopt=Abstract antibiotics, tetracycline




Biochem Med Metab Biol. 1987 Feb;37(1):42-50.
Effects of oxytetracycline treatment on enzymes of hepatic glycogen metabolism in genetically diabetic (db/db) mice.

Benzo CA.

The effects of daily oxytetracycline treatment on the activities of hepatic glycogen synthase, glycogen phosphorylase, plasma glucose, and insulin, and on liver glycogen, free fatty acid, and triglyceride levels were examined in 8- to 15-week-old genetically diabetic and lean mice. Oxytetracycline administration resulted in substantial reductions in the plasma glucose and immunoreactive-insulin levels in both diabetic and lean mice. The drug had no significant effect on the liver glycogen content in either phenotype, regardless of age, but it increased hepatic lipids and depressed body weights in lean animals. The most prominent effect of the drug was in markedly altering the activities of both glycogen synthase and phosphorylase in the liver of older diabetic mice. Oxytetracycline treatment produced a three-fold increase in the percentage of glycogen synthase I activity and reduced by one-third the percentage of glycogen phosphorylase a activity in 15-week-old diabetic mice. In age-matched lean mice treated with oxytetracycline, the percentage of glycogen synthase I activity increased significantly, but the percentage of phosphorylase a activity was unchanged. These data suggest that the drug may alter an aspect of hepatic glycogen metabolism which might lead to an inhibition of glycogenolysis and subsequent diminution of blood sugar levels in the diabetic. The present results show that, while oxytetracycline may be effective in reducing the severity of some of the diabetic symptoms associated with carbohydrate metabolism in this animal model of maturity-onset diabetes, the drug may have adverse effects on aspects of protein and lipid metabolism in these animals.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3105560&dopt=Abstract antibiotics, tetracycline