TY - JOUR
T1 - The effect of L-thyroxine supplementation in a neonatal rat model of ROP
AU - Wren, Siobhan
AU - Leske, David
AU - Mutapcic, Lejla
AU - Fautsch, Michael
AU - Holmes, Jonathan
N1 - Funding Information:
Supported by National Institutes of Health grant EY12798 (J.M.H.), Research to Prevent Blindness, Inc., New York, New York (J.M.H. as RPB Olga Keith Weiss Scholar and an unrestricted grant to the Mayo Clinic College of Medicine, Department of Ophthalmology), Mayo Foundation, Rochester, Minnesota, and the philanthropy of Margaret Schroeder (J.M.H.). Presented in part at the Association for Research in Vision and Ophthalmology annual meeting, May 4, 2005, in Fort Lauderdale, Florida.
PY - 2006/8/1
Y1 - 2006/8/1
N2 - Purpose: The role of L-thyroxine in retinopathy of prematurity (ROP) is controversial. Recent animal studies suggest both high and low levels of serum thyroxine (exogenous supplementation and pharmacologic inhibition) are associated with preretinal neovascularization (NV) or retinal vascular retardation, a precursor of NV. To address this controversy, we studied L-thyroxine supplementation in an animal model of ROP. Methods: Five hundred newborn Sprague-Dawley rats were raised in 20 expanded litters of 25, under conditions of fluctuating high and low oxygen and high carbon dioxide, to induce preretinal neovascularization. Rats received either 3 days of intraperitoneal T4, 7 days of T4 or saline control. Doses of T4 ranged from 0.005 μ g/g to 0.5 μ g/g. Retinae from left eyes were dissected, flat-mounted, and ADPase-stained. The presence and severity of NV, retinal vascular area, and retinal vascular density were scored in a masked manner. Results: The incidence of NV was similar in rats receiving either 3 days of T4 or 7 days of T4 and saline controls (55% and 43% NV in 3-day experiments [0.05 μ g g -1 day -1 and 0.5 μ g g -1 day -1 ] compared with 51% in saline controls, p = 0.49; 52% and 38% in 7-day experiments [0.005 μ g g -1 day -1 and 0.05 μ g g -1 day -1 ], p = 0.22). Retinal vascular area and vessel density were also similar to saline controls. Conclusions: Systemic T4 supplementation does not increase, or decrease, the incidence or severity of preretinal neovascularization in an animal model of ROP, despite its positive effect on overall animal growth. Further work is needed to elucidate the potential role of premature infant hypothyroidism in the pathogenesis of ROP.
AB - Purpose: The role of L-thyroxine in retinopathy of prematurity (ROP) is controversial. Recent animal studies suggest both high and low levels of serum thyroxine (exogenous supplementation and pharmacologic inhibition) are associated with preretinal neovascularization (NV) or retinal vascular retardation, a precursor of NV. To address this controversy, we studied L-thyroxine supplementation in an animal model of ROP. Methods: Five hundred newborn Sprague-Dawley rats were raised in 20 expanded litters of 25, under conditions of fluctuating high and low oxygen and high carbon dioxide, to induce preretinal neovascularization. Rats received either 3 days of intraperitoneal T4, 7 days of T4 or saline control. Doses of T4 ranged from 0.005 μ g/g to 0.5 μ g/g. Retinae from left eyes were dissected, flat-mounted, and ADPase-stained. The presence and severity of NV, retinal vascular area, and retinal vascular density were scored in a masked manner. Results: The incidence of NV was similar in rats receiving either 3 days of T4 or 7 days of T4 and saline controls (55% and 43% NV in 3-day experiments [0.05 μ g g -1 day -1 and 0.5 μ g g -1 day -1 ] compared with 51% in saline controls, p = 0.49; 52% and 38% in 7-day experiments [0.005 μ g g -1 day -1 and 0.05 μ g g -1 day -1 ], p = 0.22). Retinal vascular area and vessel density were also similar to saline controls. Conclusions: Systemic T4 supplementation does not increase, or decrease, the incidence or severity of preretinal neovascularization in an animal model of ROP, despite its positive effect on overall animal growth. Further work is needed to elucidate the potential role of premature infant hypothyroidism in the pathogenesis of ROP.
KW - Neovascularization
KW - Oxygen-induced retinopathy
KW - ROP
KW - Thyroxine
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U2 - 10.1080/02713680600788171
DO - 10.1080/02713680600788171
M3 - Article
C2 - 16877275
AN - SCOPUS:33746824626
SN - 0271-3683
VL - 31
SP - 669
EP - 674
JO - Current Eye Research
JF - Current Eye Research
IS - 7-8
ER -