GENETIC VALUE OF ESTIMATION OF THYROXINE SECRETION RATE

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Proc. Japan Conf. Radioisotopes

OSTI ID:4699739

Turner, C W

A method of estimating the thyroxine secretion rate (TSR) of domestic and laboratory animals was developed using I/sup 131/ as a tracer. It is based on the injection of I/sup 131/ measurement of thyroidal-I/sup 131/, blockage of recycling of I/sup 131/ with a goitrogen, and then blocking the release of thyroidalI/sup 131/ with increasing administration. The estimated TSR is the minimal amount of thyroxine required to inhibit thyrotropin secretion and thyroidal-I/sup 131/ release. The wide variation in TSR of individual animals is considered of great significance. Under uniform environmental conditions these differences are suggested to be genetically determined. Since thyroxine plays an important role in reproduction, growth, and lactation, animals in which TSR is above average, yet within the normal range, the TSR would be expected to grow, more rapidly and lactate at higher levels. It is suggested further that selection of breeding animals based upon their TSR will resuit in progeny of higher productive potential. Studies were made which indicate the role of environment in influencing TSR and those reproductive processes influenced by thyroxine. Experiments indicating the role of thyroxine in influencing the growth of the mammary glands of rats and the intensity of milk secretion are reported. (H.M.G.)

• Research Organization: Univ. of Missouri, Columbia
• NSA Number: NSA-17-030050
• OSTI ID: 4699739
• Journal Information: Proc. Japan Conf. Radioisotopes, Journal Name: Proc. Japan Conf. Radioisotopes Vol. Vol: 5th, No. 2
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANIMALS
BREEDING
ENVIRONMENT
GENERAL AND MISCELLANEOUS
GENETICS
GLANDS
INJECTION
IODINE 131
MEASURED VALUES
MILK
THYROID
TRACER TECHNIQUES
VARIATIONS