OXYTOCIN
STRUCTURE:-
It is a peptide containing exactly 9 amino acids. All the 7 amino acids are the same as found in vasopressin except for the isoleucine and leucine. Oxytocin being a peptide uses PIP2 secondary messenger system to bring about its effect on the target cells.
This hormone is secreted from the posterior part ofthe pituitary gland through the hyothalamo-hypophyseal tract.The hormones are transporte by carrier proteins called neurophysins. At the axon terminals they are directly released into the blood stream.
FUNCTIONS:-
REGULATION:-
It is a peptide containing exactly 9 amino acids. All the 7 amino acids are the same as found in vasopressin except for the isoleucine and leucine. Oxytocin being a peptide uses PIP2 secondary messenger system to bring about its effect on the target cells.
This hormone is secreted from the posterior part ofthe pituitary gland through the hyothalamo-hypophyseal tract.The hormones are transporte by carrier proteins called neurophysins. At the axon terminals they are directly released into the blood stream.
FUNCTIONS:-
- Oxytocin induces the contraction of uterus during parturation. Levels of oxytocin in the blood rise on the time of child birth.
- Because it is known to induce contraction it can also stop post parturum bleeding by contraction of ruptured blood vessels at the placental site.
- In the males and non pregnant females xytocin is involved in sexual arousal and orgasm. It also inducesa feeling of sexual satiety.
- Oxytocin also causes milk letdown in women wose breasts are producing milk under the effect of prolactin. Oxytocin acts upon the myoepithelial cells that surround the alveoli. These undergo contraction and in turn contract the alveoli, forcing the ilk into the ductal system and out into the infants mouth with positive pressure. This milk is ejection ot let down.
REGULATION:-
- It shows nervous regulation. Its release is totally under the controll of specific stimuli like suckling and stretching of the uterus and cervix.
- The non sexual role of oxytocin is to promote nuturing and affectionate behaviour and hence it s also known as the cuddle hormone. [19]
DISORDERS of Oxytocin:-
- Reduced secretion of oxytocin in pregnant women at the time of parturation and post partum, during lactation can be corrected by oxytocic drugs.Pitocin is a synthetic oxytocic drug.
- In males and non pregnant females effects of reduced or increased oxytocin levels are not known.