Abstract
The retardation of growth and maturation of the thyroidectomized foetal lamb suggests that maternal thyroid hormone does not cross the ovine placenta in sufficient quantities to permit normal foetal development (Hopkins & Thorburn, 1970). Assessments of the permeability of the ewe's placenta to thyroxine (T4) have previously been undertaken using labelled hormone. Dussault & Fisher (1970) found no evidence of placental transfer, although other workers have concluded that transfer does occur (Comline, Nathanielsz & Silver, 1970; Burrow, Anderson & Quilligan, 1969). Long-term studies investigating the transport of unlabelled T4 have not been reported. The aim of the present study was to investigate the transfer of maternal T4 across the placenta of the ewe during the last 6 weeks of pregnancy. Surgical thyroidectomy was performed on two foetal lambs of approximately 110 days' gestation. Indwelling carotid catheters (1·5 mm o.d., 1·0 mm i.d.) inserted at the time of
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
