Effects of certain antioxidants on lipid peroxidation process in lung homogenates of L thyroxine-receiving rats.
OBJECTIVE
A possible role of antioxidants in thyreotoxicosis was investigated. We examined the parameters of lipid peroxidation (LPO): conjugated dienes (CD), malondialdehyde (MDA), Schiff bases (SB) in lung homogenates of male Wistar rats.


METHODS
Two control groups were created: Group 1 - intact animals and Group 2 - animals injected with 0,9% NaCl. In Experiment I, the animals received L-thyroxin (LT4) i.p. (Groups 3-7). After one week the rats received additionally: Group 4 - melatonin (MEL); Group 5 - propylthiouracil (PTU); Group 6 - Ambroxol (AMB); Group 7 - N-acetylocysteine (NAC). In Experiment II, the animals received only antioxidants.


RESULTS
In Experiment I, we noticed a significantly higher MDA and SB level in Group 2, compared to that in Group 1. Moreover, we observed a significantly higher MDA and SB level in Group 3, vs. that in Group 1, but SB level was lower in Group 3 than in Group 2. Melatonin, PTU and NAC reduced CD; PTU, AMB diminished MDA and MEL, AMB lowered SB levels as compared to Group 3. In Experiment II, we observed significantly higher MDA and SB level in Group 2, vs. that in Group 1. Melatonin, AMB and NAC decreased MDA and SB level, when compared to Group 2 but PTU elevated MDA and SB level vs. that in Group 1.


CONCLUSIONS
1) L-T4 suppresses LPO, 2) MEL, AMB and NAC protect against LPO, 3) PTU is an antioxidant in thyreotoxicosis, however, when administered alone, it enhances LPO, 4) stress accelerate LPO.
Department of Endocrine Disorders and Bone Metabolism, Medical University of Lodz, Poland.
Joanna A
JA
Wiktorska
Andrzej
A
Lewinski
Michal
M
Stuss
Dariusz
D
Nowak
Tadeusz
T
Pietras
Ewa
E
Sewerynek
D000111:Acetylcysteine / Q000494:pharmacology; D000551:Ambroxol / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D013956:Antithyroid Agents / Q000008:administration & dosage / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical; D016166:Free Radical Scavengers / Q000494:pharmacology; D007274:Injections, Intraperitoneal; D015227:Lipid Peroxidation / Q000187:drug effects*; D008168:Lung / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D008550:Melatonin / Q000008:administration & dosage / Q000494:pharmacology; D011441:Propylthiouracil / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012545:Schiff Bases / Q000032:analysis; D013974:Thyroxine / Q000008:administration & dosage* / Q000494:pharmacology; D014020:Tissue Extracts / Q000378:metabolism*; D014284:Triiodothyronine / Q000097:blood
D000975:Antioxidants; D013956:Antithyroid Agents; D016166:Free Radical Scavengers; D012545:Schiff Bases; D014020:Tissue Extracts; D014284:Triiodothyronine; D000551:Ambroxol; D008315:Malondialdehyde; D011441:Propylthiouracil; D008550:Melatonin; D013974:Thyroxine; D000111:Acetylcysteine