EFFECTS OF PCB AND PBB ISOMERS ON TRIIODOTHYRONINE SECRETION AND DEGRADATION, ADRENAL FUNCTION AND CATIONIC TRANSPORT

DANIEL WAYNE SEPKOVIC, Fordham University

Abstract

Polychlorinated biphenyl Aroclor-1254, 1242 and hexabromobiphenyl or octabromobiphenyl were administered separately to 4 groups of rats (n = 8) at 50 ppm in the food for 7 months. Serum triiodothyronine (T(,3)) in the Aroclor-1254 group (27.20 (+OR-) 3.44ng/l--ml) and the Aroclor-1242 group (21.50 (+OR-) 0.76ng/100ml) were lower (P < 0.05) than control values (31.38 (+OR-) 1.22ng/100ml) and day zero values. Serum T(,3) in hexabromobiphenyl treated rats (25.00 (+OR-) 1.92ng/100ml) was lower (P < 0.05) than control and day zero values. No significant deviation in serum T(,3) from rats treated with 50 ppm octabromobiphenyl was apparent. The biological half-life (t 1/2) of L-{('125)I} T(,3) was increased (P < 0.05) in the Aroclor-1254 group (28.87 (+OR-) 1.81h) and decreased (P < 0.05) in the hexabromobiphenyl group (19.02 (+OR-) 2.06h) when compared to control values (21.23 (+OR-) 0.42h). The triiodothyronine distribution space (T(,3)DS) was found to be enlarged (P < 0.05) in the Aroclor-1254 group (67.41 (+OR-) 5.74ml) and in the Aroclor-1242 group (65.04 (+OR-) 4.13ml). This disappearance rate of L-{('125)I} T(,3) was slower in the Aroclor-1254 group than in the control.^ To evaluate the effects of PCB and PBB on cell membrane cationic transport, erythrocytes from the treatment groups were assessed for ('86)Rb flux. In K('+) free media for 1 hr, PCB Aroclor-1254 erythrocytes had decreased (P < 0.05) ('86)Rb uptake (117.82 (+OR-) 11.55ng/1.5 x 10('6) cells) when compared to control values (335.50 (+OR-) 33.59ng). In Na('+) free media, ('86)Rb uptake was decreased (P < 0.05) in erythrocytes from the Aroclor-1254 group (21.53 (+OR-) 2.76ng) and increased (P < 0.05) in the octabromobiphenyl group (132.82 (+OR-) 12.57ng) when compared to control values (58.81 (+OR-) 12.04ng).^ Serum dehydroepiandrosterone (D) levels were assessed for each treatment group. Rats from the Aroclor-1242 group had depressed (P < 0.05) serum D levels at day 45 (4.35 (+OR-) 0.35ug) over control values (6.83 (+OR-) 0.63ug) for the same time period. Serum D in the octabromobiphenyl group were decreased (P < 0.05) at day 106 (4.60 (+OR-) 0.67ug). Serum D concentrations in the hexabromobiphenyl group were decreased (P < 0.05) by day 148 (4.20 (+OR-) 0.70ug) over control values (7.04 (+OR-) 0.92ug) for the same time period.^ Liver weights were increased in the Aroclor 1254 group and in both PBB treatment groups. Thyroid weights were increased (P < 0.05) in the Aroclor-1254 group and in the hexabromobiphenyl group. ^

Subject Area

Animal Physiology

Recommended Citation

SEPKOVIC, DANIEL WAYNE, "EFFECTS OF PCB AND PBB ISOMERS ON TRIIODOTHYRONINE SECRETION AND DEGRADATION, ADRENAL FUNCTION AND CATIONIC TRANSPORT" (1982). ETD Collection for Fordham University. AAI8213257.
https://fordham.bepress.com/dissertations/AAI8213257

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