Subchronic toxicity of pentachlorobiphenyl congeners N-126 Or N-118 in the rat-liver: an electron-microscope study

3,3',4,4',5-pentachlorobiphenyl (PCB) or congener n. 126 and 2,3',4,4',5-pentachlorobiphenyl or congener n. 118 were given independently to male and female Sprague-Dawley weanling rats. Experimental diets were prepared by dissolving the congeners in 4% corn oil. The congeners were administered as follows: congener n. 126 - groups of three animals, either male or female, in each group were placed on the respective diets containing 0.1, 1.0, 10.0 ppb congener, 5.0 mu g/kg bw loading dose + 10.0, or 100 ppb; congener n. 118 - the females were dosed with 2, 20, 200, and 2,000 ppb congener, and the males received 10, 100, 1,000, 10,000 ppb. Thirteen weeks after the start of dosing with the two congeners, liver samples were obtained from all the animals and prepared for electron microscopy. In the congener n. 126-exposed animals, the alterations noted in a dose-related fashion consisted of a marked increase in the profiles of smooth endoplasmic reticulum (SER), and in the heightened number of lipid droplets in many parenchymal cells. Mitochondria showed abnormalities such as dumb-bell shapes, and the cristae parallel to the long axis of the organelle. Lipofuscin granules were numerous in the liver of animals that received 100 ppb of the congener; notably the females of the treatment group expressed this trait more abundantly than the males of the group. We conclude that the compound is mildly toxic. In the animals administered congener n. 118, the alterations were revealed in the liver of both male and female animals in a dose-related manner, also the most evident hepatocyte architectural modifications included an augmentation of SER profiles, mitochondrial aberrations, and an elevated number of lysosomal elements and lipid droplets. Abnormal shapes, and cristae in atypical orientation comprised mitochondrial aberrations. Alterations in the liver morphology of the females were qualitatively similar to those in the males; however, the dose levels used in the latter were fivefolds of that which were given to the females. We conclude that the females are more sensitive than the males of the species to congener n. 118. We further conclude that congener n. 118 is less toxic than n. 126 since the lesions were induced by severalfolds high dose levels used for the former.PT: J; CR: ALLEN JR, 1973, ARCH ENV CONTAM TOXI, V1, P265 ALVARES AP, 1982, LIVER BIOL PATHOBIOL, P265 AMAGASE H, 1975, ARCH HISTOL JPN, V38, P285 BAUMANN M, 1983, ARCH ENVIRON CON TOX, V12, P509 CHUI YC, 1985, TOXICOL APPL PHARM, V81, P287 CLARKE DW, 1984, CAN J PHYSIOL PHARM, V62, P1253 COLBORN TE, 1990, GREAT LAKES GREAT LE, R19 COLLINS WT, 1980, AM J PATHOL, V99, P125 DENBESTEN C, 1991, TOXICOL APPL PHARM, V111, P69 DURHAM SK, 1989, TOXICOL PATHOL, V17, P536 DURHAM SK, 1989, TOXICOL PATHOL, V17, P782 ELANGBAM CS, 1991, B ENVIRON CONTAM TOX, V47, P321 FISHBEIN L, 1974, ANNU REV PHARMACOL, V14, P139 FOLCH J, 1957, J BIOL CHEM, V226, P497 GHADIALLY FN, 1988, ULTRASTRUCT PATHOL, V1, P191 GILLETTE DM, 1987, FUND APPL TOXICOL, V8, P15 GILLETTE DM, 1987, FUND APPL TOXICOL, V8, P5 GOLUB MS, 1991, ENVIRON HEALTH PERSP, V94, P245 HANSELL MM, 1974, TOXICOL APPL PHARM, V28, P418 HARKNESS MR, 1993, SCIENCE, V259, P503 HARRIS C, 1984, ARCH ENVIRON CON TOX, V13, P715 HEINOMEN T, 1982, TOXICOLOGY, V22, P297 HINTON DE, 1978, VIRCHOWS ARCH B, V27, P279 JONSSON HT, 1981, ARCH ENV CONTAM TOXI, V10, P171 KASZA L, 1978, J ENVIRON PATHOL TOX, V1, P241 KIMBROUGH RD, 1972, ARCH ENVIRON HEALTH, V25, P354 KITCHIN KT, 1983, ENVIRON RES, V32, P134 KYLE ME, 1991, HDB TOXICOLOGIC PATH, P71 LIN FS, 1979, ARCH ENV CONTAM TOXI, V8, P321 MACLELLAN K, 1993, ANAT REC S, V1, P39 MANNELLA CA, 1992, J STRUCT BIOL, V108, P227 NARBONNE JF, 1979, TOXICOLOGY, V14, P91 NISHIHARA Y, 1985, BRIT J IND MED, V42, P128 NISHIHARA Y, 1986, BIOCHEM PHARMACOL, V35, P3335 NISHIZUMI M, 1970, ARCH ENVIRON HEALTH, V21, P620 ROSS MH, 1989, HISTOLOGY TEXT ATLAS, P17 SAFE S, 1990, CRIT REV TOXICOL, V21, P51 SATO T, 1968, J ELECTRON MICROSC, V17, P158 SCHECTER A, 1984, BANBURY REPORT, V18, P177 SCHECTER A, 1985, ENVIRON HEALTH PERSP, V60, P241 SEGLEN PO, 1992, EXPERIENTIA, V48, P158 SINGH A, 1981, PATHOLOGY, V13, P487 SINGH A, 1993, EXPERIENTIA, V49, A91 STONE R, 1992, SCIENCE, V255, P798 STOTZ IJ, 1978, B ENVIRON CONTAM TOX, V19, P319 TEHSEEN WM, 1992, B ENVIRON CONTAM TOX, V48, P101 TONER PG, 1992, OXFORD TXB PATHOLOGY, V1, P173 WEISS L, 1988, CELL TISSUE BIOL TXB, P1 ZAJICEK G, 1992, PATHOL RES PRACT, V188, P410; NR: 49; TC: 13; J9: J SUBMICROSC CYTOL PATHOL; PG: 13; GA: NJ074Source type: Electronic(1