Immunological quantitation of rat and mouse thyroxine-binding globulins. Ontogenesis and sex-dependence of the circulating levels of the thyroxine-binding globulins

Abstract

Abstract. We describe the preparation of monospecific antisera against a thyroxine-binding globulin partially purified from immature rat sera by affinity chromatography on thyroxine-Sepharose. The antisera are used for the rocket immunoelectrophoresis assay of rat thyroxinebinding globulin and also, owing to their partial crossreactivity with mouse thyroxine-binding globulin, for the quantitation of this serum binding protein in the mouse. The thyroxine-binding globulin is measured in developing rats and in sexually mature male and female rats and mice. The results of the ontogenetic study confirm the postnatal surge of serum thyroxine-binding globulin levels, formerly demonstrated with binding techniques. They allow further to define the correlations, dependent on age, of the immunoquantitated thyroxine-binding globulin and transthyretin levels with the abilities of the sera to bind thyroxine. In sexually mature rats and mice we demonstrate an opposite sexdependence of thyroxine-binding globulin levels, characterized by increased levels of the protein in the female rats versus increased levels of the protein in the male mice. This is the first report of immunological quantitation of rat and mouse thyroxine-binding globulins.

Amyloid and Nonfibrillar Deposits in Mice Transgenic for Wild-Type Human Transthyretin: A Possible Model for Senile Systemic Amyloidosis

“…In animals bearing the mutant construct, the amount of human TTR in the serum was between 1 and 3 mg/dl, the difference reflecting the gene dose in the two strains. (The normal human serum TTR concentration is between 10 and 40 mg/dl, [Smith and Goodman, 1971], whereas normal mouse serum contains 20 to 30 mg of murine TTR/dl of serum [Vranckx et al, 1990]). The levels increased up to 3 to 4 months of age, stabilized The human transthyretin (TTR) gene was cloned as a 19.2 kb NheI fragment, containing all the sequences known to be required for tissue specific expression, in Charon 40 grown in either Escherichia coli ED 8767 or K 802.…”

Role of thyroid hormones in human and laboratory animal reproductive health

“…Compared to humans, albumin appears to be the major binding protein in adult rodents. Rodents contain a gene that can encode the TBG protein, but it is expressed at very low levels in adult animals (Vranckx et al, 1990;Rouaze-Romet et al, 1992;Tani et al, 1994). Developmental studies show TBG protein levels increase during the early postnatal period in rodents, but then decline to very low levels by weaning and remain low through the remainder of the animal's life span (Savu et al, 1987(Savu et al, , 1991Vranckx et al, 1990).…”

“…For example, TBG levels are higher in adult female rats and humans when compared to adult male rats and humans. In contrast, TBG levels are higher in adult male mice when compared to adult female mice (Vranckx et al, 1990). Another example is seen when evaluating TBG levels during pregnancy.…”

Re-expression of thyroxine-binding globulin in post-weaning rats during protein or energy malnutrition

“…The two thyroid hormone binding proteins, TBG and TTR, were purified from rat sera and the corresponding specific antibodies were raised in rabbits, as described in detail elsewhere (11,20). Their serum concentrations were measured by the rocket electroimmunodiffusion technique (21).…”

“…Here we have used the immunological and molecular biology tools that we have developed for the identifica¬ tion and quantification of rat TBG (11,16) to analyze its responses to deficient nutritional conditions involving either protein or energy restriction. The studies were performed at various intervals during 28 days of experi¬ mental diet administration, on rats aged 4 weeks at the beginning of the experiments, i.e.…”