The effects of oestradiol and relaxin on extensibility and collagen organisation of the pregnant rat cervix.
The effects of exogenously introduced oestradiol-17 beta (E) and relaxin (RLX) on cervical extensibility and collagen organisation were tested in rats ovariectomised in late pregnancy. When the cervices were stretched in vitro by 1 mm increments, it was found that those from rats given E alone generated significantly higher tensions than those from control rats, while cervices from rats given both E and RLX had tensions similar to controls. Examination of cervical sections under the light microscope and ultra-thin sections under the electron microscope showed that the collagen fibres in the cervices from E-treated rats were highly organised, whereas those from animals given E+RLX and control animals were disorganised and dispersed. It was concluded that E decreased cervical extensibility, while RLX counteracted the effect of E to maintain a soft and easily extensible cervix.
Cheah
S H
SH
Department of Physiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
Ng
K H
KH
Johgalingam
V T
VT
Ragavan
M
M
D000818:Animals; D002584:Cervix Uteri / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D003094:Collagen / Q000648:ultrastructure; D004548:Elasticity; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D008854:Microscopy, Electron; D010052:Ovariectomy; D011247:Pregnancy; D051381:Rats; D012065:Relaxin / Q000494:pharmacology
D012739:Gonadal Steroid Hormones; D004958:Estradiol; D012065:Relaxin; D003094:Collagen