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Old 06-20-2012
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Help Prolactin Feedback ?

Question: What is the feedback of Prolactin on the hypothalamus?

DIT said that Prolactin has negative feedback on the Hypothalamus BUT FA 2009 Pg 281 says that Prolactin increases dopamine synthesis & secretion from the hypothalamus ?

What's the right answer ?

Thanks
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Old 06-20-2012
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Quote:
Originally Posted by Hope2Pass View Post
Question: What is the feedback of Prolactin on the hypothalamus?

DIT said that Prolactin has negative feedback on the Hypothalamus BUT FA 2009 Pg 281 says that Prolactin increases dopamine synthesis & secretion from the hypothalamus ?

What's the right answer ?

Thanks
In a way its the same thing, because Prolactin does have feedback on the hypothalamus by increasing the dopamine, but dopamine in turn decreases secretion of Prolactin by acting on anterior pituitary, so basically decreasing levels of prolactin.

I hope it helps. I just recently did this part of DIT as well. Good luck!
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Old 06-20-2012
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Quote:
Originally Posted by Hope2Pass View Post
Question: What is the feedback of Prolactin on the hypothalamus?

DIT said that Prolactin has negative feedback on the Hypothalamus BUT FA 2009 Pg 281 says that Prolactin increases dopamine synthesis & secretion from the hypothalamus ?

What's the right answer ?

Thanks
Its the way they phrased that .. that it makes it ridiculously difficult

Prolactin has a negative feedback effect on the hypothalamus

Its simple as that.

DIT says

Prolactin has negative feedback effect on hypothalamus.

Yes, prolactin in excess amounts directly acts on the hypothalamus to increase dopamine release.

Dopamine is --------> Prolactin inhibiting factor.

So its negative feedback effect.


FA says.

Prolactin acts on hypothalamus to increase the secretion of dopamine and its synthesis.

What will happen ?

Same negative feedback effect. It will inhibit further release of prolactin.


Final Concept:

FOR ALL PHYSIOLOGICAL PURPOSES PROLACTIN HAS A NEGATIVE FEEDBACK EFFECT ON HYPOTHALMUS

It prevents further release of prolactin by secreting dopamine from the hypothalamus which is prolactin inhibiting factor.
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