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A further non-reproductive role of activin is it's role in skin lesions where it is thought to stimulate keratinocytes.

A further non-reproductive role of activin is it's role in skin lesions where it is thought to stimulate keratinocytes.

===Prostaglandin F_2αO===

===Prostaglandin F_2α===

Prostaglanin is a C₂O fatty acid and is produced within the uterine endometrium and vesicular glands. Estradiol stimulates prostaglandin synthesis while progesterone inhibits it. The target tissue in the female is the [[Corpus_Luteum_Regression_-_Anatomy_%26_Physiology|corpus luteum]], uterine myometrium and ovulatory follicles. In the female PGF_2α cause luteolysis and can also cause the induction of tone and contractions within the uterus. It plays an important role in partuition in ruminants.

Prostaglanin is a C₂O fatty acid and is produced within the uterine endometrium and vesicular glands. Estradiol stimulates prostaglandin synthesis while progesterone inhibits it. The target tissue in the female is the [[Corpus_Luteum_Regression_-_Anatomy_%26_Physiology|corpus luteum]], uterine myometrium and ovulatory follicles. In the female PGF_2α cause luteolysis and can also cause the induction of tone and contractions within the uterus. It plays an important role in partuition in ruminants.

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If a pregnancy is to remain viable then luteolysis needs to be avoided and this is achieved where concentrations of PGF_2α remain below a threshold level allowing the corpus luteum to continue to secrete progesterone and thus maintain pregnancy. There are two main factors involved in the regulation of uterine secretions of PGF_2α; oxytocin secretions from the corpus luteum and molecules secreted by the developing embryo that facilitate the maternal recognition of pregnancy.

If a pregnancy is to remain viable then luteolysis needs to be avoided and this is achieved where concentrations of PGF_2α remain below a threshold level allowing the [[Corpus_Luteum_Regression_-_Anatomy_%26_Physiology|corpus luteum]] to continue to secrete progesterone and thus maintain pregnancy. There are two main factors involved in the regulation of uterine secretions of PGF_2α; oxytocin secretions from the [[Corpus_Luteum_Regression_-_Anatomy_%26_Physiology|corpus luteum]] and molecules secreted by the developing embryo that facilitate the maternal recognition of pregnancy.

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Oxytocin secretion via the corpus luteum stimulates endometrial production of PGF_2α and by the end of the [[Oestrous_Cycle_-_Anatomy_%26_Physiology|luteal phase]] the concentration of oxytocin and the number of oxytocin recptors within the endometrium allow the production of enough PGF_2α to breach the threshold level and cause luteolysis. During pregnancy the embryonically produced [[Maternal_Recognition_of_Pregnancy_-_Anatomy_%26_Physiology|pregnancy recognition]] molecules inhibit the secretion of PGF_2α from the endometrium ensuring that luteolysis cannot occur.

Oxytocin secretion via the [[Corpus_Luteum_Regression_-_Anatomy_%26_Physiology|corpus luteum]] stimulates endometrial production of PGF_2α and by the end of the [[Oestrous_Cycle_-_Anatomy_%26_Physiology|luteal phase]] the concentration of oxytocin and the number of oxytocin recptors within the endometrium allow the production of enough PGF_2α to breach the threshold level and cause luteolysis. During pregnancy the embryonically produced [[Maternal_Recognition_of_Pregnancy_-_Anatomy_%26_Physiology|pregnancy recognition]] molecules inhibit the secretion of PGF_2α from the endometrium ensuring that luteolysis cannot occur.

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The ovarian artery is wrapped around the uterine vein. This creates a countercurrent mechanism by which the lipid soluable prostaglandins are able to diffuse from the uterine vein into the [[Ovary_-_Anatomy_%26_Physiology#Arterial_Supply|ovarian artery]]. During the latter stages of the [[Oestrous_Cycle_-_Anatomy_%26_Physiology|luteal phase]] as PGF_2α production increases luteolysis will occur as PGF_2α Is able to reach its target in the ovary before being metabolized in systemic circulation.

The [[Ovary_-_Anatomy_%26_Physiology#Arterial_Supply|ovarian artery]] is wrapped around the uterine vein. This creates a countercurrent mechanism by which the lipid soluable prostaglandins are able to diffuse from the uterine vein into the [[Ovary_-_Anatomy_%26_Physiology#Arterial_Supply|ovarian artery]]. During the latter stages of the [[Oestrous_Cycle_-_Anatomy_%26_Physiology|luteal phase]] as PGF_2α production increases luteolysis will occur as PGF_2α Is able to reach its target in the ovary before being metabolized in systemic circulation.

===Prostaglandin (PGE₂)===

===Prostaglandin (PGE₂)===