Endocrinology, Vol 116, 1200-1205, Copyright © 1985 by Endocrine Society

ARTICLES

The physiological role of relaxin in the pregnant rat. I. The influence of relaxin on parturition

SJ Downing and OD Sherwood

Length of gestation, duration of labor and delivery, and fetal survival were determined in control intact pregnant rats (group C). Pregnant rats were bilaterally ovariectomized on day 9 and given progesterone (P) implants and, in addition, one of the following injection regimens; estrogen (E; group OPE), E and porcine relaxin (R; group OPER), or porcine R (group OPR). Hormone treatments were given in doses designed to produce serum levels of these hormones similar to those observed in intact pregnant rats. The P implants were removed during the evening of day 21 to mimic the decline in serum P levels that normally occurs as a result of luteolysis. Animals in groups OPE and OPR exhibited significantly prolonged gestation, prolonged duration of labor and delivery, and reduced fetal survival compared with controls. Group OPER animals exhibited slightly but not significantly shorter length of gestation, similar duration of labor and delivery, and similar rate of fetal survival compared to control values. Group OPER animals showed normal maternal behavior and were able to suckle their young.

This article has been cited by other articles:

				R. Gonzalez-Fernandez, E. Martinez-Galisteo, F. Gaytan, J. A. Barcena, and J. E. Sanchez-Criado Changes in the Proteome of Functional and Regressing Corpus Luteum During Pregnancy and Lactation in the Rat Biol Reprod, July 1, 2008; 79(1): 100 - 114. [Abstract] [Full Text] [PDF]

				H.-Y. Lee, S. Zhao, P. A. Fields, and O. D. Sherwood The Extent to which Relaxin Promotes Proliferation and Inhibits Apoptosis of Cervical Epithelial and Stromal Cells Is Greatest during Late Pregnancy in Rats Endocrinology, January 1, 2005; 146(1): 511 - 518. [Abstract] [Full Text] [PDF]

				O. D. Sherwood Relaxin's Physiological Roles and Other Diverse Actions Endocr. Rev., April 1, 2004; 25(2): 205 - 234. [Abstract] [Full Text] [PDF]

				H.A. Rodriguez, L. Kass, J. Varayoud, J.G. Ramos, H.H. Ortega, M. Durando, M. Munoz-de-Toro, and E.H. Luque Collagen remodelling in the guinea-pig uterine cervix at term is associated with a decrease in progesterone receptor expression Mol. Hum. Reprod., December 1, 2003; 9(12): 807 - 813. [Abstract] [Full Text] [PDF]

				L. Zhao, P. J. Roche, J. M. Gunnersen, V. E. Hammond, G. W. Tregear, E. M. Wintour, and F. Beck Mice without a Functional Relaxin Gene Are Unable to Deliver Milk to Their Pups Endocrinology, January 1, 1999; 140(1): 445 - 453. [Abstract] [Full Text]

				S. Zhao and O. D. Sherwood Monoclonal Antibodies Specific for Rat Relaxin. X. Endogenous Relaxin Induces Changes in the Histological Characteristics of the Rat Vagina During the Second Half of Pregnancy Endocrinology, November 1, 1998; 139(11): 4726 - 4734. [Abstract] [Full Text] [PDF]

				E. H. Luque,, M. M. Muñoz de Toro,, J. G. Ramos,, H. A. Rodriguez,, and O. D. Sherwood Role of Relaxin and Estrogen in the Control of Eosinophilic Invasion and Collagen Remodeling in Rat Cervical Tissue at Term Biol Reprod, October 1, 1998; 59(4): 795 - 800. [Abstract] [Full Text]

				L. L. Burger and O. D. Sherwood Relaxin Increases the Accumulation of New Epithelial and Stromal Cells in the Rat Cervix during the Second Half of Pregnancy Endocrinology, September 1, 1998; 139(9): 3984 - 3995. [Abstract] [Full Text] [PDF]