Endocrine system and mammary glands

[Impulse155]

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So the posterior pituitary gland produces oxytocin which can cause the stimulation and secretion of milk in the mammary glands. Is this production due to an effect on the anterior pitutiary to produce prolactin or does it directly effect the mammary gland itself.

Thanks 🙂

 

[dental diva]

This is what I gathered while studying (and the internet, haha) it looks like the two hormones are not dependent on each other, but both of them are in response to the same stimulus (in this case, suckling). Oxytocin actually pushes the milk out, whereas prolactin is responsible for producing the milk itself.

The posterior pituitary doesn't synthesize oxytocin (and ADH)--only secretes it. Oxytocin is synthesized in the hypothalamus, then transported via axons to the posterior pituitary. The posterior pituitary then secretes the oxytocin.

Prolactin is a direct hormone secreted by the anterior pituitary, and it stimulates production of mRNA of proteins for milk.

So in a nutshell, it looks like oxytocin directly effects the gland itself. But correct me if I'm wrong please 🙂

 

[asdfray]

I think diva is correct with the info.

Oxytocin and ADH/AVP are secreted by magnocellular neurosecretory cells within the supraoptic and paraventricular nucleus of the hypothalamus. These hormones synapses on blood vessels at the posterior pituitary gland. In addition, Oxytocin also plays a necessary role in child birth, along with Progesterone (contraction).

Prolactin is secreted by acidophils (ex. mammotrophs/lactotrophs) and its secretion is directly affected by dopamine secretion at the hypothalamus? (This is what I remember from Endocrinology - could be wrong) Also, Dopamine acts at the hypothalamus on a negative feedback regulation.

I don't think Oxytocin would directly stimulate Prolactin production or vise-versa. Hope that helped. =)