BACKGROUND AND PURPOSE Clinical research of drugs is a researching step subsequent to the preclinical studies in experimental animals. The aim of our research was to evaluate animal model of wound healing process after the burn inducement and effects of the ointment containing natural plants on the process of burn healing. MATERIAL AND METHODS Burn wounds were experimentally induced in two species of experimental animals which were treated with topically applied herbal preparation with concomitant monitoring of the healing process. Experimental groups (1) of 15 animals each (mice and rats), while control group (2) of 10 animals each (mice and rats) that were not being treated with herbal ointment. After the hair removal, burn was induced on the back of animals by heated brass seal. Different clinical symptoms including oedema of surrounding tissue, redness, exudation, size of the burn surface, histological and microbiological findings were monitored on the days 1, 3, 7, 14 and 21. A statistically significant difference was observed throughout descriptive statistics and paired Student's t-test. CONCLUSION Physiological healing processes of the acute burn wound following the topical application of herbal preparation can be monitored on the utilized animal model. A three-week treatment resulted in the 90% of completed epithelization in both animal species, indicating the effectiveness of topically applied herbal preparation.

Experimental studies of burns require the use of different animal models with the aim to imitate and reproduce pathophysiological conditions. The aim of this work was to establish experimental model of thermal injury. New Zealand rabbits, weighted from 1.8 kg to 2.3 kg, were utilised during our study. Another, also utilized, animal types were laboratory Rattus rats, species Wistar, albino type, females with body weight of about 232 g. All animals were from our own litter (Institute of Pharmacology, Clinical Pharmacology and Toxicology, Faculty of Medicine in Sarajevo). During the experiment, animal were properly situated in adequate cages and rooms, at the controlled temperature (22 +/- 2 degrees C), and in the air with normal humidity level. All animals took food and water ad libitum. Rabbits received anesthesia--intravenous pentobarbital sodium in a dose of 60 mg/kg, and then, hair from the upper side of the each rabbit ear was removed and burns were caused by a metal seal in the same manner as in rats. Rats were primarily anesthesied by intraperitoneal pentobarbital sodium in a dose of 35 mg/kg, and then, their hair was removed from the scapula zone (5 cm x 5 cm). Burns were caused by contact with a round metal seal, heated at 80 degrees C in a water bath, during the period of 14 seconds together with contact thermometer control. Round metal seal (radius: 2.5 cm; weight: 100 g; surface: 5 cm2) was just placed on the rat skin without any additional pressure. In order to maintain the microcirculation in the burn wound and to reduce the conversion of partial-thickness skin burns to the burns of the full-thickness skin, all burn wounds were immediately sunk in the 4 degrees C water. Subsequent to that procedure, all animals were individually situated in the proper cages, and left to rest for 4 hours with a constant cautious monitoring of the wound development and animal general state.

The present study was undertaken to investigate the changes in composition of the mammary gland volume unit through all phases of lactation in rats subjected to lead acetate administration via drinking water during the first pregnancy and lactation. Stereological analysis was performed on serial slices of the organs. The point of support for our study was the fact that lead, apart from being a poison of wide range, is mostly poisonous for gonads and to their supervisory neuroendocrine structures and the mammary gland, in morpho-functional sense, should be admitted as their integral part. On the 7th day of lactation there was significant difference of the alveolar and ductal epithelium phase, which was significantly reduced in animals treated by lead. In the same animals there were larger lumens of the alveoli and ducti, more abundant connective tissue and greater number of the adipocytes but these differences in comparison to control group were not significant. On the 14th day of lactation there was significantly greater presence of the adipocytes phase and stromal tissue while the volume of the epithelium of alveoli and ducti was significantly reduced in study group. There was also an increase of the alveoloductal lumen phase but this was not significant. On the 21st day of lactation there were significant difference in epithelial and stromal tissue phases in two groups, having a significant decrease in the epithelium, and significant increase of stromal tissue in glands of lactating rats treated by lead acetate. There were non-significant differences as far as the presence of the adipocytes and alveoloductal lumen volume were concerned although the values for both phases in study group were above the control values. On the basis of given results we concluded that lead changes the quantitative characteristics of the mammary gland, i.e. the composition of the volume unit of the organ through all phases of lactation.