Zinc content in the diet affects the activity of Cu/ZnSOD, lipid peroxidation and lipid profile of spontaneously hypertensive rats.

The present study focused on the effect of Zn containing diets on the activity of superoxide dismutase (Cu/ZnSOD), systolic blood pressure (SBP), lipid peroxides (ROOH) and lipids (LDL, HDL, triglycerides and cholesterol) in male spontaneously hypertensive rats (SHR). Three experimental groups of animals were studied: a control (G1-40 mg), and two with zinc-supplemented diets (G2-100 and G3-160 mg Zn/kg lab chow). The diets were introduced at the beginning of the development of hypertension (2 months after birth) and the animals were fed for 8 weeks. The activity of CuZnSOD in erythrocytes was determined by spectrophotometry with the use of RANSOD kit (RANDOX Laboratories Ltd., UK). Atomic-absorption spectrometry was used to determine Zn and Cu concentrations in the rat's sera. A significantly increased Cu/ZnSOD activity was found in G3 compared with rats fed with control diet G1 (p = 0.020). SBP was significantly decreased in G3 in relation to G1 (p = 0.0048). The lipid hydroperoxide concentration was significantly decreased in G3 compared with G1 (p = 0.016) and G2 (p = 0.005). Zinc supplement affected lipids profile by decreasing LDL and increasing HDL. The present data suggest that Zn concentration in the diet plays an important role in the regulation of SBP and can be a critical nutrient for maintenance of anti-oxidative events in SHR.

[Clotting induction in the mesenterium and erosive stomach mucosa in wistar rats as the result of a catenoidal ultrasonic transducer]. / Tromboobrazuvane v mezenterium i erozirana stomashna ligavitsa na plukh poroda Wistar sled vusdeistvie s katenoidalen ultrazvukov preobrazuvatel.

The ultrasonic transducers and instruments used in surgery operate in the range of 1-10 MHz and release significant heat in the surroundings. They need additional cooling system which significantly raises the cost and impedes the equipment operation. Hemostasis can be successfully achieved by employing ultrasonic transducers that operate in the kilohertz range, avoiding the occurrence of inadmissible tissue overheat outside the area of the transducer performance. The paper presents results of the approbation of the effect of a periodical acoustic signal with frequency of 60 kHz over the erosive stomach mucosa and mesenterium of 28 rats, "Wistar" breed, and the period of tissue exposure is 1-10 min. A transducer-catenoidal semi-wave concentrator that provides maximum emitted power of the ultrasonic wave is used and thermal effects are avoided. It is proved that the use of a powerful and localized ultrasonic signal results in erythrocyte diapedesis and forms microhaemorrhagies together with an out-vessel coagulation in the rat stomach mucosa The tissue damages are strictly limited within the area of the emitter contact and they are subject to control during the ultrasonic performance.

[The morphological changes in the liver in experimentally induced hypercholesterolemia]. / Morfologichni promeni v cherniia drob pri eksperimentalno predizvikana khiperkholesterolemiia.

The authors examined the liver of 20 rabbits "Newzeland white" and "Chinchila", undergone atherogenic diet with cholesterol (0.3-0.5 g/kg body weight) for 30 and 60 days. They determined cholesterol, lipids, triglicerides and beta-lipoproteins in the serum. The morphologic study revealed accumulation of cholesterol in the hepatocytes, fibrosis, proliferation of the bile ducts and signs of hepatic cirrhosis.

The influence of neonatal thymectomy on the blood serum level of total lipids, NEFA, triglycerides, total cholesterol and beta-lipoproteins in rats.

The time course of changes in the blood serum content of total lipids (TL), nonesterified fatty acids (NEFA), triglycerides (TG), total cholesterol (TC) and beta-lipoproteins (beta-LP), caused by neonatal thymectomy (NTE), was investigated in neonatally thymectomized and in sham-operated rats aged 15, 30, 45 days, 2, 3 and 5 months. TL were significantly increased on days 15, 30, 45 and 60 after operation; their level in 3- and 5-month-old rats was already normal. In control rats, NEFA level increased with age; their level in NTE rats was significantly higher on days 15, 30, 45 and 60 after thymectomy. Similar changes were registered in TG level. The effect of NTE was most pronounced in TC whose level was significantly higher in thymectomized rats than in control rats till the 150th day after operation. Serum concentration of beta-LP in NTE rats exceeded several times that of sham-operated rats in all age groups. The role of the thymus in the control of lipid metabolism in rats is discussed.

Binding of haemoglobin to the red-cell membrane in the presence of copper chloride.

Methaemoglobin may be an important factor for initiation and development of lipid peroxidation in Cu(II)-treated red blood cells. It seems likely that the initiation of peroxidation by methaemoglobin is only possible if direct contact between haemoglobin molecule and the cell membrane is realized. In view of this, the binding of haemoglobin to the red-blood-cell membrane in the presence of CuCl2 was studied. It was found that the haemoglobin quenching of the fluorescence of 12-(9-anthroyl)stearic acid-labelled red-blood-cell membranes greatly increases in the presence of CuCl2. This effect is relatively independent of pH and the ionic strength of the medium, indicating that in this case the binding of haemoglobin is not electrostatic in nature. The haemoglobin quenching of the fluorescence of the inside-out and the right-side-out resealed ghosts were almost the same in the presence of CuCl2. This result suggests that, in the presence of ionic copper, both surfaces of the membrane possess approximately equal amounts of sites for the binding of haemoglobin.