1. The authors report the results obtained after the action of certain optotoxic substances on several enzyme activities in the retina of the pig. 2. This in vitro study involved enzyme interferences of the following optotoxic agents : ethionamide, d-penicillamine, ethylene diaminotetra-acetic acid (EDTA), disodium and dicobalt salts. The enzyme activities studied involved glycolysis, the enzymes selected being as follows: glucose phosphate isomerase (GPI, E.C. 5.3.1.9), fructose-1,6-diphosphate aldolase (F1-6diPA, E.C. 4.1.2.13), lactate dehydrogenase (LDH, E.C. 1.1.1.27). 3. Following the action of the effectors studied, a marked decrease in the enzyme activities examined was found in the retina. This decrease, of varying rapidity and regularity, went as far in some cases as total inhibition; there was disturbance of glycolysis. 4. These results indicate the existence of interactions with a complex mechanism. It may be noted that all of the effectors studied were chelating agents of divalent metals and the changes which they induced in the enzyme activities examined may be explained by interference of the chelates formed with metal cations, such as Zn++, co-factors or effectors of these glycolysis enzymes (with the exception of GPI). These stable chelates are formed by virtue of the primary amine--NH2, thiol--SH, thionyl-[Formula: see text] groups, i.e. groups belonging to molecules essential to cell metabolism.

Animals↗

PubMedDate not supplied

[The interaction of Cupressus sempervirens L. proanthocyanidolic oligomers with elastase and elastins].

Cupressus sempervirens L. proanthocyanidolic (O.P.C.) oligomers inhibited the esterolytic activity of pancreatic elastase with a Cl50 of 0.0075 mg/ml when a sap substrate suc(Al)3NA was used in a Tris-HCl 0.05 M buffer with a pH of 7.5. Inhibition was slightly lower when the ionic strength of the buffer was increased. Elastolytic activity was inhibited using an elastinorcein substrate with a Cl50 of 0.05 mg/ml, whatever the pH or the ionic strength of the buffer. The oligomers bound with the elastase to form a precipitant complex where a 2 mg/ml concentration of oligomers precipitated the elastase at 1 mg/ml. Insoluble elastin fixed few 150 micrograms oligomers for 1 mg of elastin but the latter was partly protected by the subsequent action of the elastase. Soluble elastin fixed a greater number of oligomers but it was the peptids of elastin enzyme hydrolysis which fixed the largest amount: around 1500 micrograms per mg. The oligomers-elastin complex seems to be more stable than that of oligomers-elastase which regains part of its esterase activity. The elastic fibers seem to be protected by the O.P.C.

Elastin↗

PubMedDate not supplied

[Propolis extract. I. Acute toxicity and determination of acute primary cutaneous irritation index].

In first part, the aim of this work is to study the orally subacute toxicity of a propolis extract on conscious mice. LD50 is more than 7.34 g/kg propolis extract: this product is not toxic. In second part, cutaneous primary irritation of several products: excipients and propolis extract alone or in ointments, is evaluated in the rabbit. The cutaneous reactions after reiterated applications for 14 days are observed. The index of cutaneous primary irritation is calculated by evaluation of the erythematous and oedematous lesions. The propolis extract is non irritant.

Animals↗

PubMedDate not supplied

[Propolis extract. II. Wound healing the the rat and rabbit].

This work is related to wounds healing properties of a propolis extract. In first study on the Albinos Rabbit, the activity of a propolis extract is compared with these of a Peru balsam. Optimal concentrations of them in ointments are evaluated by applications on deep cutaneous scarifications. In order to go further into details, we have chosen in second part, another assay on the Rat, allowing the obtention of deeper wounds; By this way, more complete quantification of retained parameters and a better appraising of the wounds healing process evolution are possible.

Animals↗