Effect of tolfenamic acid on the metabolism of the main connective tissue components in rats.

Tolfenamic acid (Clotam) has been used in the therapy of rheumatic diseases for some years. Regarding its chemical structure it belongs to the group of fenamates. The effect of tolfenamic acid on the synthesis of collagen and proteoglycans in granulation tissue, skin or cartilage of rat weanlings was tested and compared with the action of mefenamic acid. According to the results obtained, tolfenamic acid is a potent inhibitor of collagen as well as proteoglycan syntheses. The concentrations of the constituents of proteoglycans, i.e. protein core, link protein as well as glycosaminoglycans were decreased in the tissue after treatment with tolfenamic acid. In comparison with mefenamic acid, if the same doses were used (50 mg and 100 mg/kg of body weight/day in in vivo experiments and 10 mg/g wet tissue in in vitro experiments), tolfenamic acid exhibits more distinct inhibitory effect. A general inhibitory effect of tolfenamic acid on proteosynthesis is suggested.

Protein binding of tolfenamic acid in the plasma from patients with renal and hepatic disease.

The protein binding of tolfenamic acid in plasma from patients with renal and hepatic disorders was studied by equilibrium dialysis. Drug binding to the cellular components of whole blood and blood cell suspensions was also measured. Salicylic acid was used as the reference drug in all experiments. Renal and hepatic diseases increased the unbound fraction of tolfenamic acid. Free drug fractions were significantly correlated with changes in creatinine, urea, and total bilirubin, but not with those in albumin or total protein in plasma. Comparison of the theoretical binding parameters in control plasma and similar changes in protein binding in all the plasma samples studied revealed that tolfenamic acid and salicylic acid probably share a common primary binding site. The significance of the correlation permits use of salicylic acid as a model drug for predicting changes in the protein binding of tolfenamic acid. The measurements of binding properties in whole blood and blood cell--buffer suspension showed that tolfenamic acid interacts with the lipid membrane structures of blood cells, while salicylic acid is distributed into the aqueous cell space.

Comparison of saliva and urine samples in thin-layer chromatographic detection of central nervous stimulants.

The excretion of amphepramone, amphetamine, ephedrine and prolintane was estimated qualitatively from saliva and urine using thin-layer chromatography (TLC) 1, 2, 4, 8, 12 and 24 h after a single intake of therapeutic doses by healthy volunteers. The purpose was to compare the suitability of these two biological fluids for doping tests and it was therefore important that either the drug or its metabolites should be found in all subjects. Ephedrine was the only one to be detected regularly in saliva already 1 h after drug intake, and it was found there up to 8 h, while in urine it was found up to 24 h. In saliva, prolintane or its main metabolite did not appear during 24 h, whereas it or its metabolite were consistently found in urine 4-12 h after drug intake. Neither amphepramone nor its metabolites were detected at any time in saliva, but this drug was found, either in unchanged or in metabolized form, in urine 1-24 h after intake. The same was true for amphetamine, except at 1 h in urine. The findings did not clearly correlate with the pH of either saliva or urine samples. It is concluded that in TLC screening saliva is inferior to urine in doping tests.

Intestinal absorption of tolfenamic acid at experimental malabsorption states in rats.

Absorption kinetics of 14C-labelled N-(3-chloro-o-tolyl)-anthranilic acid (tolfenamic acid, 14C-TA, Clotam) from the small intestine was studied in intact rats and in rats with malabsorption states provoked by methotrexate, starvation, and triparanol. 14C-TA was administered intravenously and intraduodenally, and the drug concentrations in the blood were followed up radiometrically. A multi-compartmental model was applied for mathematical analysis. Theoretical model parameters were computed, and absorption parameters were then derived from the theoretical ones. The absorption half-life of 14C-TA was 5.3 min in the controls, 10.8 min in the methotrexate-intoxicated, 7.5 min in the fasted, and 5.3 min in the triparanol-intoxicated rats. The absorbed fraction of the intraduodenal 14C-TA dose was 100% in each experimental group as well as in the controls. It is suggested that the slower transfer of 14C-TA through the intestinal barrier in the methotrexate-intoxicated and fasted rats may be caused by the reduction of the absorptive surface.

ATPase stimulated by Na+ or K+ in gills of the freshwater mussel Anodonta.

1. Microsomal preparations from the gills of the freshwater mussel anodonta cygnea cellensis show Mg2+ -dependent Na+ - or K+ -stimulated ATPase activity, which is not inhibited by ouabain. 2. Na+ - or Ka+ -ATPase activity is decreased by Ca2+, acetylcholine, choline, and tetramethylammonium, but slightly increased by ethyl alcohol. 3. It is tentatively suggested that Na+ - or K+ -ATPase is involved in the mechanism of active monovalent cation uptake through the gills of freshwater mussels.

Weight, stroma to gland ratio, and mitotic activity of the human hyperplastic prostate.

The growth of the hyperplastic prostate of 12 patients was studied with an in vitro 3H-thymidine labeling method. The prostates were weighed and the stroma to gland ratio was analyzed. The mitotic activity of the glandular epithelium averaged 0.36 per cent (+/- 0.06 SE). No mitotic activity was found in the stromal tissue. There was a positive correlation between the weight of the prostate and the labeling Index of the glandular epithelium. Thus, the prostatic hyperplasia of these patients appeared to be purely glandular in form. The stroma to gland ratio was 70 to 80 per cent. It was found that most of the glandular follicles were mitotically quiescent, and that the mitotic activity was concentrated in a few of the follices. The results indicate that the growth of the hyperplastic prostate is caused both by the mitotic activity (hyperplasia) of the glandular epithelium and by the stromal hypertrophy. Thus, in vitro assay of the mitotic activity of the prostatic biopsies can be used for the estimation of the weight of the hyperplastic prostate. The possible role of the stroma in regulation of the mitotic activity of the glandular epithelium has been discussed.

A simple method for the clinical determination of the mitotic activity of the human prostate in vitro.

Patients with a hyperplastic prostate were studied for the epithelial mitotic activity of adenomatous tissue by the (3)H-thymidine labelling method. A simple method in vitro was improved for biopsy samples. The mitotic activities obtained in vitro were compared with those obtained in vivo. The results show that the mitotic activity is not affected by the short incubation of the samples in Tyrode's balanced salt solution.