Oxytocin

By: Victoria Lee

Produced?

• Oxytocin is a nine amino acid peptide hormone synthesized in magnocellular neurosecretory cells in the hypothalamus and released by the posterior lobe of the pituitary gland. The sequence is cysteine - tyrosine - isoleucine - glutamine - asparagine - cysteine - proline - leucine - glycine).

Target Cell

• Mammary alveoli are surrounded by smooth muscle (myoepithelial) cells which are a prominant target cell for oxytocin.

What Causes it to be Produced?

• It is produced when a woman is pregnant to help her go into labor.

• The stimulation causes neurons that make oxytocin to fire action potentials in intermittent bursts; these bursts result in the secretion of pulses of oxytocin from the neurosecretory nerve terminals of the pituitary gland.

Structure?

• Peptide

If too much is produced?

• Overdosage - Effects of overdosage on the uterus depend on the stage of the uterus and the position of the fetus(es). Hypertonic or tetanic contractions can occur leading to tumul tuous labor, uterine rupture, fetal injury or death.