Effects of hypothyroidism on vascular /sup 125/I-albumin permeation and blood flow in rats

Journal Article · Mon May 01 00:00:00 EDT 1989 · Metab., Clin. Exp.; (United States)

DOI:https://doi.org/10.1016/0026-0495(89)90201-1· OSTI ID:5717222

Tilton, R G; Pugliese, G; Chang, K; Speedy, A; Province, M A; Kilo, C; Williamson, J R

Effects of hypothyroidism on vascular 125I-albumin permeation and on blood flow were assessed in multiple tissues of male Sprague-Dawley rats rendered hypothyroid by dietary supplementation with 0.5% (wt/wt) 2-thiouracil or by thyroidectomy. In both thiouracil-treated and thyroidectomized rats, body weights, kidney weight, arterial blood pressure, and pulse rate were decreased significantly v age-matched controls. After 10 to 12 weeks of thiouracil treatment, 125I-albumin permeation was increased significantly in the kidney, aorta, eye (anterior uvea, choroid, retina), skin, and new granulation tissue, remained unchanged in brain, sciatic nerve, and heart, and was decreased in forelimb skeletal muscle. A similar pattern was observed in thyroidectomized rats, except that increases in 125I-albumin permeation for all tissues were smaller than those observed in thiouracil-treated rats, and 125I-albumin permeation in retina did not differ from controls. In both thiouracil-treated and thyroidectomized rats, changes in blood flow (assessed with 15-microns, 85Sr-labeled microspheres) relative to the decrease in arterial blood pressure were indicative of a decrease in regional vascular resistance except in the choroid and in the kidney, in which vascular resistance was increased significantly. Glomerular filtration rate was decreased, but filtration fraction and urinary excretion of albumin remained unchanged by thiouracil treatment and thyroidectomy. These results indicate that vascular hemodynamics and endothelial cell barrier functional integrity are modulated in many different tissues by the thyroid. In view of the correspondence of hypothyroid- and diabetes-induced vascular permeability changes, these results raise the possibility that altered thyroid function in diabetes may play a role in the pathogenesis of diabetic vascular disease.

• Research Organization: Washington Univ. School of Medicine, St Louis, MO (USA)
• OSTI ID: 5717222
• Journal Information: Metab., Clin. Exp.; (United States), Vol. 38:5
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ALBUMINS
MEMBRANE TRANSPORT
BLOOD VESSELS
PERMEABILITY
HYPOTHYROIDISM
BIOLOGICAL EFFECTS
VASCULAR DISEASES
PATHOGENESIS
BLOOD FLOW
BLOOD PRESSURE
IODINE 125
KIDNEYS
MICROSPHERES
RATS
STRONTIUM 85
THYROID
TISSUE DISTRIBUTION
TRACER TECHNIQUES
ALKALINE EARTH ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR SYSTEM
DAYS LIVING RADIOISOTOPES
DISEASES
DISTRIBUTION
ELECTRON CAPTURE RADIOISOTOPES
ENDOCRINE DISEASES
ENDOCRINE GLANDS
EVEN-ODD NUCLEI
GLANDS
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
RODENTS
STRONTIUM ISOTOPES
VERTEBRATES
550901* - Pathology- Tracer Techniques