Vessel wall modification in venous pathology. Application to the study of phlebotonic drugs.

Pathophysiological investigation of varicose veins show extensive metabolic perturbation and structural parietal changes. Oxygen consumption is reduced more than three-fold while levels of activity of proteolytic enzymes from lysosomes are significantly raised. Connective tissue in the venous wall undergoes profound deterioration, with a decrease in collagen fibrils and an increase in proteoglycans. Recent studies of venous endothelial cells in hypoxia have provided an etiological explanation for these disorders. These disturbances in the venous wall are of a magnitude sufficient to produce defectable changes in serum and urine of patients with varicose veins. All the foregoing data provide a basis for a pharmacological approach allowing an improved understanding of the mechanism of action of phlebotonics and the selection of the most active agents.

Effect of milacemide, a glycinamide derivative, on the rat brain gamma-aminobutyric acid system.

Milacemide (CP 1552 S, 2-n-pentylaminoacetamide), a drug with anti-epileptic potency, increases the gamma-aminobutyric acid (GABA) content specifically in the substantia nigra of rat brain. The effect is dose-related from 25 to 100 mg/kg p.o. The time course shows that at 100 mg/kg p.o. after 2, 3 and 4 hr the substantia nigra GABA content is significantly increased by 28, 33 and 38%, respectively. After 6 hr the GABA contents return to the control value. After repeated oral administration of milacemide a comparable effect to acute administration is obtained. After degeneration of the striato-nigral GABA-ergic pathway, milacemide no longer enhances the content of GABA in the substantia nigra. GABA-transaminase activity measured ex vivo in rat brain homogenate is not influenced by milacemide. On the other hand, the glutamate decarboxylase activity measured ex vivo 3 hr after 100 mg/kg of milacemide is significantly increased by 11% in homogenates of the whole rat brain. The results show that milacemide increases the GABA content in the GABA pool which is associated with the striato-nigral neurons. This increase is not due to GABA-transaminase inhibition but might be the result of an enhanced synthesis, possibly through glutamate decarboxylase activation.

Determination of individual hydroxyethyl rutosides in various animal body fluids by thin-layer chromatography and scanning densitometry.

A method is described for the accurate determination in plasma of the beta-hydroxyethylrutosides by measurement of the fluorescence of their borocitrate complexes by scanning densitometry following separation by thin-layer chromatography. A modification is also described for estimation of individual hydroxyethylrutosides and their glucuronide conjugates in samples of bile and urine.

N-acetylgalactosamine-6-sulfate sulfatase in man. Absence of the enzyme in Morquio disease.

Human N-acetylgalactosamine-6-sulfate sulfatase (6-sulfatase) activity is measured by using as a substrate a sulfated tetrasaccharide obtained by digesting purified chondroitin-6-sulfate (C-6-S) with testicular hyaluronidase. The amount of inorganic sulfate released is measured turbidimetrically. The enzyme from human kidney has a pH optimum of 4.8; its activity is augmented by low levels of NaCl and inhibited by phosphate and high levels of NaCl. Free glucuronate, acetylgalactosamine, inorganic sulfate, polymeric C-6-S, or tetrasaccharide obtained from chondroitin-4-sulfate do not affect the enzyme activity. The method may be used for the diagnosis of Morquio disease since extracts of Morquio fibroblasts are devoid of 6-sulfatase activity.

Micromethod for the determination of glycosaminoglycans in the serum. Results from the serum of healthy and varicose subjects.

Serum glycosaminoglycans (GAG) were isolated from 1 ml of serum by a modification of the method of Y. Emura and T. Mukuda (J. Jap. Biochem. Soc., 45 (1973) 30). The extraction was carried out as quantitatively as possible and the hexuronic acids in the GAG were measured with m-hydroxydiphenyl. This method for determination of the GAG is relatively easy, easily reproducible and requires no more than two days. Its application in clinical chemistry may prove to be useful in the detection of diseases involving connective tissue. A study was carried out with serum samples from 34 patients suffering from serious varicose conditions, compared with samples fro 30 healthy subjects. The mean concentration of GAG in the serum of healthy persons was 0.602 +/- 0.108 (p smaller than 0.0005). There were not, however, any significant variations between patients suffering from serious varices without trophic changes and those with comparable varices accompanied by trophic changes, such as phlebitis, thrombosis and ulcers.