The hepatocellular thyroid status of uremic rats estimated from the abundances of thyroid hormone-dependent nucleoplasmic proteins.

Although the serum thyroxine (T4) and triiodothyronine (T3) concentrations of uremic rats are commensurate with moderate hypothyroidism, their thyroid status at the tissue level remains controversial. To help establish the hepatocellular thyroid status of uremic rats, a novel tissue marker (nuclear protein abundances) was evaluated in uremic rats (U), hypothyroid rats (H), and hypothyroid uremic rats (HU). Uremia was established by five-sixths nephrectomy. Moderate hypothyroidism was established by partial thyroidectomy or by provision of drinking water supplemented with propylthiouracil and T4. Normal rats (N) and pair-fed, sham-operated rats (1 to 3 weeks after surgery) served as controls. Animals were killed 1 to 5 weeks postoperatively. The following values were obtained 5 weeks after surgery, at which time the total and free serum T4 and T3 levels of the hypothyroid rats (H) were equivalent to those of the uremic rats (U). Total T4 (micrograms/dL +/- 1 SD): N, 5.4 +/- 1.7; H, 2.2 +/- 0.5; U, 1.9 +/- 1.5; HU, 0.5 +/- 0.0. Free T4 (ng/dL +/- 1 SD): N, 535 +/- 165; H, 126 +/- 37; U, 135 +/- 89; HU, 26 +/- 1. Total T3 (ng/dL +/- 1 SD): N, 63 +/- 20; H, 39 +/- 14; U, 38 +/- 18; HU, 13 +/- 4. Free T3 (ng/dL +/- 1 SD): N, 7.83 +/- 3.00; H, 3.87 +/- 1.05; U, 3.47 +/- 1.73; HU, 0.94 +/- 0.47. Hepatocellular thyroid status was estimated from the relative abundances of two nucleoplasmic proteins on polyacrylamide gel electrophoregrams.(ABSTRACT TRUNCATED AT 250 WORDS)