Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2007-4-3
pubmed:abstractText
The material properties of the anterior cruciate ligament (ACL) in female rats with normal estrous cycles were compared to those regulated by oral contraceptive steroids. Forty female Sprague-Dawley rats were divided into two groups: an experimental group received daily ethinylestradiol and levonorgestrel in a dosing model designed to simulate a typical oral contraception regime in humans, while a control group received daily oral placebo. After eight cycles, six rats from each group underwent daily phlebotomy to measure serum estradiol and progesterone levels over the course of a single 5-day estrous cycle. Significant differences between groups were found for the area under the curve of blood progesterone levels versus time over the length of the estrous cycle (P=0.02). After 12 cycles, the rats were euthanized and one femur-ACL-tibia complex from each animal was dynamically loaded to failure. The ACLs from the rats in the experimental group had significantly decreased average and tangent stiffness, (P=0.002 and 0.0001, respectively), and significantly increased elongation (P=0.002) and total energy absorbed (P=0.03), or greater toughness than controls. In rats, it appears that the administration of reproductive hormones designed to simulate typical oral contraception in humans alters the mechanical properties of the rat ACL.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0942-2056
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
453-60
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Reproductive hormone effects on strength of the rat anterior cruciate ligament.
pubmed:affiliation
Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, WA, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't