Hypericin-induced phototoxicity in cultured fibroblasts and swine erythrocytes.

Hypericin is a naturally occurring photosensitizer, whose presence in plants has been responsible for cutaneous phototoxicity in grazing animals. The photosensitizing properties of this agent have recently been exploited in models for anti-tumor and anti-viral activity. The cytotoxicity of hypericin and light was assessed in 3T3 mouse fibroblasts using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide)] assay and the lactate dehydrogenase (LDH) leakage assay. Membrane damage was assessed in swine erythrocytes using hemolysis, potassium (K+) leakage and formation of lipid hydroperoxides. Concentration- and light-dependent decreases in fibroblast viability were seen starting at hypericin concentrations of 1.25 microM and light power flux levels of 24 J/cm2 using a visible light source and at 0.417 microM hypericin and a similar light dose using a solar simulator. No LDH leakage was observed at hypericin concentrations up to 30 microM and visible light up to 144 J/cm2. Light-and/or concentration-dependent increases in hemolysis, K+ leakage and formation of lipid hydroperoxides in red blood cell (RBC) membranes were observed, but at concentrations and light doses much greater than those required to induce cytotoxicity in fibroblasts. Lipid peroxidation and hemolysis occurred at 15 microM hypericin and 24 J/cm2 (visible light source). Potassium ion leakage occurred at concentrations and light levels as low as 5 microM and 12 J/cm2 or 15 microM and 4.8 J/cm2 (visible light source) but was still a less sensitive indicator than fibroblast cytotoxicity. Evidence for both type I and type II reactions was shown in RBC membranes by TLC analysis of cholesterol products. In the absence of light, hypericin appears to be relatively nontoxic in the models tested.

Comparative skin phototoxicity in mice with two photosensitizing drugs: benzoporphyrin derivative monoacid ring A and porfimer sodium (Photofrin).

Benzoporphyrin derivative monoacid ring A (BPD-MA) and Photofrin (porfimer sodium) are photodynamic anticancer agents. The chemical structures of the two regioisomers of BPD-MA are 9-methyl trans-(+/-)-18-ethenyl-4,4 alpha-dihydro-3,4- bis(methoxycarbonyl)-4 alpha, 8,14,19-tetramethyl-4,4 alpha-dihydro-3,4- bis(methoxycarbonyl)-4 alpha, 8,14,19-tetramethyl-23H,25H-benzo(b)porphine- 9,13-dipropanoate and 13-methyl-trans-(+/-)-18-ethenyl-4,4 alpha-dihydro-3,4- bis(methoxycarbonyl)-4 alpha, 8,14,19-tetramethyl-23H,25H-benzo(b)porphine- 9,13-dipropanoate. Photofrin (a registered trademark of American Cyanamid Co.) is a polyporphrin oligomer containing ester and ether linkages. The ability of BPD-MA or Photofrin to cause skin phototoxicity was investigated in mice exposed to simulated sunlight (light) 3, 24, or 48 hr after receiving a single intravenous injection of vehicle or 2, 10, or 20 mg/kg of BPD-MA or Photofrin. The data were from two studies conducted using male and female CD1 mice (approximately 7 weeks old). The hair of the dorsal thoracic area was clipped 24 hr prior to exposure to light. Mice were exposed to light for 5 min. The clipped area of skin was the primary site for the evaluation of phototoxicity. Mice were observed for 2 weeks after treatment. There were no significant findings in controls or in mice given 2 mg/kg of BPD-MA. When mice were exposed to light 3 hr after dosing, both BPD-MA (10 or 20 mg/kg) and Photofrin (2, 10 or 20 mg/kg) caused phototoxicity. Death occurred in all mice given 20 mg/kg of BPD-MA or Photofrin, and in the majority of mice given 10 mg/kg of Photofrin.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of age on serum chemistry profile, electrophoresis and thyroid hormones in beagle dogs two weeks to one year of age.

Chemistry tests were conducted on serum from young Beagle dogs in order to deter mine the effect of age on these parameters. Blood was collected at regular intervals from 25 normal Beagle puppies (13 males and 12 females) at ages ranging from 2 weeks to 12 months. Serum chemistry profiles, protein electrophoresis and radioimmunoassays for thyroxine and triiodothyronine were included. Rapidly changing age related differences were observed in several parameters. Urea nitrogen, cholesterol, triglycerides, lactate dehydrogenase, thyroxine, glucose, gamma glutamyl transpeptidase, and total bilirubin values were elevated early in life, and decreased during the first 6 to 8 weeks, while alanine aminotransferase activity was low initially and increased during this period. Lactate dehydrogenase, thyroxine, gamma glutamyl transpeptidase, total bilirubin and alanine aminotransferase attained stability by 3 months, but the remaining parameters showed slight changes subsequently, gradually approaching adult values. More gradual age related changes were observed in other parameters. These included alkaline phosphatase, inorganic phosphorus and calcium values, which were higher in younger dogs, and creatinine, aspartate aminotransferase and total protein values, which were lower in younger dogs. Creatinine and aspartate aminotransferase values were stable by approximately 6 months; alkaline phosphatase, inorganic phosphorus, calcium and total protein values continued to change gradually up to 1 year.

Age-related changes in serum chemistry and hematology values in normal Sprague-Dawley rats.

Age-related changes in serum chemistry and hematology values in male and female Sprague-Dawley rats 2 to 29 months of age are described. The number of values per determination (N) ranged from 554 to 1126. Serum chemistry parameters demonstrating changes with time included inorganic phosphorus, total protein, cholesterol, triglycerides, and alkaline phosphatase. There was little or no sex difference among these parameters. Hematologic parameters demonstrating changes with time included leukocyte elements (lymphocytes, neutrophils, eosinophils, monocytes), erythrocyte parameters (red blood cell count, hematocrit, hemoglobin, mean cell volume, mean cell hemoglobin), and platelet count. Most trends in erythrocyte parameters were more marked in males than in females. To visualize the effect of age of these parameters, the data were plotted vs time, and fitted models were superimposed on the graphs. Comparisons with available literature values are made, and the value of an age-related data base when conducting long-term toxicity studies is discussed.

Reference range data base for serum chemistry and hematology values in laboratory animals.

A reference range data base containing serum chemistry and hematology values on over 3000 animals is described. Data listed include the mean, standard deviation, and 10th and 90th percentiles for each of the following parameters. Serum chemistry: sodium, potassium, chloride, calcium, inorganic phosphorus, urea nitrogen, creatinine, total bilirubin, total protein, glucose, cholesterol, triglycerides, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase (monkey only), lactate dehydrogenase (dog only), and creatine kinase (dog only). Hematology: hematocrit, hemoglobin, red blood cells, reticulocytes, mean cell volume, mean cell hemoglobin, mean cell hemoglobin percent, platelets, white blood cells, neutrophils, eosinophils, basophils, lymphocytes, monocytes, and stabs. The species included are mouse, rat, hamster, rabbit, beagle dog, and cynomolgus monkey. The use of the reference ranges in routine computerized data collection is discussed.

Measurement of estrogens in cow's milk, human milk, and dairy products.

Free natural estrogens in raw and commercial whole milk were quantitated by radioimmunoassay. The ranges of concentration of estrone, estradiol 17-beta, and estriol were 34 to 55, 4 to 14, and 9 to 31 pg/ml. Proportions of active estrogens (estrone and estradiol) in the fat phases of milk by radioactive tracer on separated milk were 80% and 65%. These findings were supported by radioimmunoassay of skim milk and butter. Equilibrium dialysis of skim milk with hydrogen 3 labeled estrogens showed that 84 to 85% of estrone and estradiol and 61 to 66% of estriol were protein bound. Whey proteins demonstrated a greater binding capacity than casein. This result was confirmed by radioimmunoassay of dry curd cottage cheese and whey. The concentrations in curd were 35, 11, and 6 pg/g. In whey they were 4, 2, and 3 pg/ml. The quantity of active estrogens in dairy products is too low to demonstrate biological activity. Butter was highest with concentrations of 539, 82, and 87 pg/g. Human colostrum demonstrated a maximum concentration of 4 to 5 ng/ml for estrone and estriol and about .5 ng/ml for estradiol. By the 5th day postpartum, they decreased to become similar to cow's milk.