Experimental gestational hypothyroidism evokes hypertension in adult offspring rats

• Published in: Autonomic neuroscience Vol. 170; no. 1; pp. 36 - 41
• Main Authors: Santos, Sheyla Oliveira, Loureiro, Saulo Makerran Araújo, Alves, Iura Gonzalez Nogueira, Jesus, Camila Santos de, Santos, Patrícia Rabelo dos, Santos, Márcio Roberto Viana dos, Dias, Daniel Penteado Martins, Santana-Filho, Valter Joviniano, Badauê-Passos, Daniel
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 25-09-2012
• Subjects: Advanced Basic Science; Animals; Autonomic nervous system; Baroreflex - physiology; Blood Pressure - physiology; Disease Models, Animal; Female; Fetal development; Gestational hypothyroidism; Heart Rate - physiology; Hypertension - complications; Hypertension - physiopathology; Hypothyroidism - chemically induced; Hypothyroidism - complications; Hypothyroidism - physiopathology; Indexing in process; Male; Medical Education; Methimazole; Pregnancy; Pregnancy Complications, Cardiovascular - physiopathology; Prenatal Exposure Delayed Effects - physiopathology; Pulse interval variability; Rats; Rats, Wistar; Rats; Pulse interval variability; Fetal development; Autonomic nervous system; Gestational hypothyroidism
• ISSN: 1566-0702; 1872-7484
• DOI: 10.1016/j.autneu.2012.07.004

Abstract Gestational hypothyroidism is a prevalent disorder in pregnant women. We aimed to investigate the impact of experimental gestational hypothyroidism (EGH) on cardiovascular and autonomic nervous systems (ANS) in the offspring of rats. EGH was induced with methimazole (MMI) 0.02% in drinking water from day 9 of gestation until birth. Sixty day old offspring from MMI-treated dams (OMTD, n = 13) or water-treated dams (OWTD, n = 13) had femoral arteries surgically assessed for the measurements of heart rate (HR), mean (MAP), systolic (SAP) and diastolic arterial pressure (DAP), and spontaneous baroreflex sensitivity (BRS). To investigate the balance of ANS, we established the high (HF) and low frequency (LF) bands of pulse interval (PI) and LF band of SAP spectrum. OMTD had increased MAP (130.2 ± 2.0 vs 108.8 ± 3.0 mm Hg, p < 0.001), SAP (157.3 ± 2.9 vs 135.7 ± 4.5 mm Hg, p < 0.001) and DAP (109.7 ± 1.9 vs 88.4 ± 2.6 mm Hg, p < 0.001) when compared to OWTD, and had lower HR (355.1 ± 8.9 vs 386.8 ± 9.2 bpm, p < 0.05). After spectral analysis of PI and SAP, only LF band of SAP spectrum was higher (7.2 ± 0.8 vs 4.0 ± 0.6 mm Hg2 , p < 0.01) in OMTD under spontaneous condition. Despite bradycardia, EGH promotes spontaneous hypertension in 60 day old offspring, probably due to increased sympathetic modulation of vessels, which is suggested by the higher LF of SAP. These findings suggest a critical role of maternal THs in the development of fetal cardiovascular and autonomic nervous systems.