Childhood lead toxicity and impaired release of thyrotropin-stimulating hormone

Journal Article · Wed Apr 01 04:00:00 EST 1987 · Environ. Res.; (United States)

DOI:https://doi.org/10.1016/S0013-9351(87)80219-0· OSTI ID:6014773

Huseman, C A; Moriarty, C M; Angle, C R

Decreased stature of children is epidemiologically associated with increased blood lead independent of multiple socioeconomic and nutritional variables. Since endocrine dysfunction occurs in adult lead workers, they studied two girls, 2 years of age, before and after calcium disodium edetate chelation for blood leads (PbB) of 19-72 ..mu..g/dl. The height of both children had crossed from the 50th to below the 10th percentile during the course of chronic lead toxicity. Basal free T/sub 4/, T/sub 4/, T/sub 3/, cortisol, somatomedin C, and sex steroids were normal. A decrease in the growth hormone response and elevation of basal prolcatin and gonadotropins were noted in one. Both children demonstrated blunted thyrotropin-stimulating hormone (TSH) responses to thyrotropin-releasing hormone (TRH) in six of seven challenges. This prompted in vitro studies of cultured cells from rat pituitarities. After incubation of pituitary cells with 0.1-10 ..mu..M Pb/sup 2 +/ for 2 hr, followed by the addition of TRH, there was a dose-dependent inhibition of TSH release Lead did not interfere with the assay of TSH. To investigate the interaction of lead and calcium, /sup 45/Ca/sup 2 +/ kinetic analyses were done on rat pituitary slices after 1 hr incubation with 1.0 ..mu..M lead. The impaired late efflux was consistent with a decrease in the size and exchangeability of the tightly bound pool of intracellular microsomal or mitochondrial calcium. The rat pituitary cell model provides a model for the decreased TSH release of lead poisoning, supports the biological plausibility of a neuroendocrine effect on growth, and suggests that interference with calcium-mediated intracellular responses is a basic mechanism of lead toxicity.

• Research Organization: Univ. of Nebraska, Omaha
• OSTI ID: 6014773
• Journal Information: Environ. Res.; (United States), Journal Name: Environ. Res.; (United States) Vol. 42:2; ISSN ENVRA
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AGE GROUPS
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
BIOLOGICAL MODELS
BODY
CALCIUM
CALCIUM 45
CALCIUM COMPOUNDS
CALCIUM ISOTOPES
CHILDREN
DAYS LIVING RADIOISOTOPES
ELEMENTS
ENDOCRINE GLANDS
EPIDEMIOLOGY
EVEN-ODD NUCLEI
GLANDS
GROWTH
HAZARDS
HEALTH HAZARDS
HORMONES
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LEAD
MAMMALS
METALS
NUCLEI
ORGANS
PEPTIDE HORMONES
PITUITARY GLAND
RADIOISOTOPES
RATS
REACTION KINETICS
RODENTS
TRACER TECHNIQUES
TRH
VERTEBRATES