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A hormone found in the serum of humans and certain other animals during pregnancy; probably acting with progesterone and estrogen, it causes relaxation of pelvic ligaments in the guinea pig.



a hormone formed mainly in the ovaries that produces relaxation of the ligaments of the pubic symphysis of the pubic bones during pregnancy; as a result, the pelvis widens and normal childbirth is facilitated. Relaxin also characteristically inhibits the spontaneous contractions of the uterus.

Chemically relaxin is a polypeptide. Refined sow relaxin exhibits pronounced basic properties; it has molecular weight of about 6,500 and a structure of two subunits, consisting respectively of 22 and 28–31 amino-acid residues, joined by a disulfide bond. The primary structure has not been determined. The biosynthesis of either relaxin or the polypeptides that are closely related to it structurally is also possible in tissues found in the uterus and placenta.

References in periodicals archive ?
The normal physiology of childbirth leads to an escalation of the levels of relaxin and progesterone, which facilitate the relaxation and consequent widening of the birth passage.
In some species, the placenta produces relaxin, a hormone that plays an important role in parturition.
However, as there would be no relaxin involved, this would not provide relief, but rather, eventually produce pain instead.
amendments to the EPC, and the time period in which Relaxin and its
What's more, when our bodies are operating in the parasympathetic mode, our systems are flooded with the compounds relaxin and serotonin.
Relaxin, one of the proteins being studied, could potentially benefit patients with asthma, hay fever, and cardiovascular disease.
One intriguing antioxidant is relaxin, identified 70 years ago in the uteruses of pregnant women and thought to be important for the relaxation of the uterus, Dr.
One particularly intriguing antioxidant is relaxin, a compound identified 70 years ago in the uteruses of pregnant women, which was thought to be important for the relaxation of the uterus, Dr.
In addition, the increase in production of the hormone relaxin (which the body uses to prepare for labor) causes a loosening of the connective tissue around those joints and creates instability.
An increase of estrogen and relaxin augments the elasticity of ligaments.