Triiodothyronine treatment maintains surfactant synthesis during sepsis.
BACKGROUND
Pulmonary compromise with altered surfactant metabolism is frequently noted during sepsis; triiodothyronine is necessary for normal surfactant synthesis. We evaluated the role of physiologic replacement of triiodothyronine during sepsis-induced hypothyroidism on surfactant synthesis and lung structural integrity.


METHODS
Male Sprague Dawley rats (average weight, 330 gm) underwent sham laparotomy or cecal ligation and puncture; treatment was administered to rats that underwent cecal ligation and puncture by Alzet osmotic pump consisting of triiodothyronine (3 ng/hr) or saline control. The rats were killed 24 hours after serum triiodothyronine determination by radioimmunoassay (normal, 60 to 160 ng/dl). Surfactant was obtained by saline lavage. Lipid content was determined by Folch extraction; phospholipid content was verified by chromatography. Blinded histologic analysis of lung confluence and alveolar sparing was done in separate subgroups. Results are +/- SE.


RESULTS
Control rats with sepsis were hypothyroid at 24 hours; rats given triiodothyronine were euthyroid (rats that underwent sham laparotomy, 67.7 +/- 4.9 ng/dl; control rats, 37.6 +/- 5.7 ng/dl; and triiodothyronine, 85.7 +/- 19 ng/dl; p less than 0.05 compared with triiodothyronine by analysis of variance). Surfactant production was significantly improved by triiodothyronine compared with control (60.7 +/- 22.6 mg vs 23.2 +/- 11.3 mg; p less than 0.05 by analysis of variance). Lung histologic integrity was maintained by triiodothyronine treatment during sepsis.


CONCLUSIONS
Triiodothyronine supplementation may be beneficial in septic-induced pulmonary dysfunction.
Dulchavsky
S A
SA
Department of Surgery, Wayne State University School of Medicine, Detroit, Mich.
Bailey
J
J
D000818:Animals; D002432:Cecum; D007239:Infections / Q000378:metabolism* / Q000473:pathology; D008026:Ligation; D008168:Lung / Q000378:metabolism; D008297:Male; D010743:Phospholipids / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000473:pathology; D011663:Pulmonary Surfactants / Q000096:biosynthesis*; D011677:Punctures; D051381:Rats; D011919:Rats, Inbred Strains; D014284:Triiodothyronine / Q000494:pharmacology*
D010743:Phospholipids; D011663:Pulmonary Surfactants; D014284:Triiodothyronine