Antioxidant defense potential, malondialdehyde (MDA) levels, and relative hydroxyl radical (OH·) concentrations were measured in order to establish the effects of extracorporeal shock wave lithotripsy (ESWL) on free radical production and antioxidant defense potential of the rabbit kidney tissues. Electron microscopic examination was also performed to observe ultrastructural changes. The antioxidant defense potential of the ESWL-treated tissues was found to be reduced, and the MDA levels increased as compared with controls. Vitamin (vitamin E plus C combination) pretreatment ameliorated antioxidant defense potential in part, prevented increases in MDA levels in the ESWL-treated tissues, and increased the antioxidant defense potential in the control kidney tissues. After ESWL, a significant amount of OH· radical was measured in the affected tissue. This revealed the source of oxidant stress and peroxidation reactions in the ESWL-treated kidney tissue. Vitamin pretreatment caused significant reduction in the OH· radical concentration. In the electron microscopic investigation, some significant subcellular changes, such as endothelial injury, loss of foot processes, damage of glomerular basal membrane, etc., were observed in the ESWL-treated renal tissue slices. Vitamin pretreatment to a great extent prevented formation of these subcellular changes. Our results suggest that the antioxidant capacity of the kidney tissue was reduced after ESWL treatment and that the tissue was exposed to oxidant stress. Vitamin pretreatment exerted significant protection against the radical damage.

Halothane causes impairment in the hepatic antioxidant defense system and accelerates peroxidation reactions. As a result, some ultrastructural changes in hepatic tissues occur due to halothane treatment. Although vitamin E prevents peroxidative damage, it does not ameliorate ultrastructural changes caused by halothane treatment. This shows that halothane toxicity results not only from impaired hepatic antioxidant defense system but also from other, unknown causes.

No abstract

We have observed four radicals in the ESR spectra of y-irradiated single crystals of some glutamic acid derivatives. These radicals, produced by gamma-irradiation, in single crystals of N-Acetyl-LGlutamic acid, L-Glutamic acid and DL-Glutamic acid hydrochloride were identified as CH3CONH, -C 3 H 5 , -CH. and -NH 2 radicals respectively.Free radicals produced by gamma irradiation in single crystals of N-Acetyl-L-Glutamic acid(l), LGlutamic acid (2) and DL-Glutamic acid hydrochloride (3) have been investigated between 100 and 350 K with ESR. The single crystal spectra have been taken at 5-degree intervals with the magnetic field B lying in each of the three crystallographic planes ab, be, and ca. Figure 1 shows the spectrum of 1 with its hyperFine splitting. In these spectra, 16-lines are observed due to CH3CONH and C3H5 radicals. Owing to the CH3CONH radical, the spectra exhibit an outer doublet (1:1) because of the proton directly attached to the nitrogen, and each of the outer lines splits into triplet lines (1:1:1) due to the nitrogen. Owing to the other allyl radical (C3H5) produced by gamma irradiation, inner 10-lines are also observed between these triplet lines. Inner doublet splittings are due to a-protons of the radical, then each line splits into Five lines (1:4:6:4:1) owing to the ^-protons of this radical. The proton splitting for the CH3CONH radical is about 8.9 mT, and the nitrogen splitting is approximately 0.8, 0.6, and 0.4 mT. The a and ß-proton splittings are approximately 3.4 and 0.6 mT, respectively. Such a result can arise if the unpaired electron interacts equally with the a-proton and to a somewhat lesser extent with four other equivalent ß-protons. The radical most likely formed in irradiated 1 which fits these requirements is the allyl radical (C3H5). The greater density of the electron at the nuclei of either a and ß protons farthest from the site of the unpaired electron can be accounted for in terms of conjugation. The

Free radicals produced by gamma irradiation in single crystals of hydroxylammonium chloride, hydroxylammonium sulfate and hydrazinium sulfate have been investigated at room temperature with ESR. The radicals in the hydroxylammonium salts were identified as •NH2 and that in hydrazinium sulfate as •N2H4+ . The ESR spectra of the radicals were unchanged and undiminished at room temperature more than eight months after irradiation. The g and hyperfine constants were found to be almost isotropic with an average g = 2.0047, aH = 2.0 mT and αN = 0.70 mT for •NH2 and g = 2.0034, aH = 1.10 mT and aN = 1.15 mT for •N2N4+ .