Influence of L-Thyroxine Administration on Poor-platelet Plasma VEGF Concentrations in Patients with Induced Short-term Hypothyroidism, Monitored for Thyroid Carcinoma

Abstract

Abstract. Angiogenesis is a process of new blood vessel development from pre-existing vasculature. It is a crucial process in normal physiology, as well as in several pathological conditions. The vascular endothelial growth factor (VEGF) represents a family of specific endothelial cell mitogens, involved in normal angiogenesis and in tumour development. The aim of the present study was to estimate the influence of L-thyroxine (L-T 4 ) administration on poorplatelet plasma (P-PP) VEGF concentrations in patients with induced short-term hypothyroidism, monitored for differentiated thyroid carcinoma. In the present study, P-PP concentrations of VEGF, thyroglobulin, thyrotropin and free thyroid hormones were investigated in a population of 24 hypothyroid patients, who were withdrawn from L-T 4 treatment for 5 weeks and studied before and after 2 months of L-T 4 therapy. Only healthy female patients with no evidence of metastasis in whole body scintigraphy were included in the study. They were then compared with 20 healthy control subjects, matched for age, sex and body mass index (BMI). The patients had significantly lower plasma VEGF concentrations before treatment with L-T 4 than after administration of that hormone. There was no significant difference in plasma VEGF levels, either between the patients treated with L-T 4 , and the controls, or between the patients untreated with L-T 4 , and the controls. Even short-time changes in thyrometabolic profile exert an important influence on P-PP VEGF concentrations, even if there is no thyroid tissue.

Thyroid Hormone Receptor-β Is Associated with Coronary Angiogenesis during Pathological Cardiac Hypertrophy

“…Wang et al (18) reported that diiodothyropropionic acid induces formation of new coronary arteries by increasing the protein expression of fibroblast growth factor, vascular endothelial growth factor (VEGF), angiopoietin-1 and endothelium-specific receptor tyrosine kinase 2 in the heart. Dedecjus et al (42) demonstrated that T 4 administration increased plasma VEGF levels. Our results from the angiogenesis-focused array show that VEGF mRNA was not changed by administration of T 3 in AAC heart, and VEGF protein expression level in coronary ECs was not affected by T 3 administration in control mice (control, 1.01 Ϯ 0.12; control ϩ T 3 , 1.01 Ϯ 0.03 arbitrary unit) or AAC mice (AAC, 0.86 Ϯ 0.13; AAC ϩ T 3 , 0.81 Ϯ 0.01 arbitrary unit, determined by Western blot).…”

Influence of thyroid state on cardiac and renal capillary density and glomerular morphology in rats

“…DITPA administration increased the protein expression of vascular endothelial growth factor (VEGF) 164 , VEGF 188 , basic fibroblast growth factor (bFGF or FGF2), angiopoietin-1 and Tie-2 and bFGF in neovascularisation around infarction areas ). More recently, T 4 treatment restored poor platelet plasma VEGF levels in hypothyroid patients to levels in euthyroid controls, but the blood vessel density was not reported (Dedecjus et al 2007).…”

Stimulatory Effects of Thyroid Hormone on Brain Angiogenesis in vivo and in vitro

“…In a chick chorioallantoic membrane model, thyroid hormone exhibited FGF-2-dependent proangiogenic effects (Davis et al, 2004). Furthermore, patients who have short-term thyroid hormone deficiency have lower VEGF blood levels that can be reversed by thyroid hormone treatment (Dedecjus et al, 2007).…”