Next what we’ll do is we’ll take a look
at these anterior pituitary peptide hormones
and then divide it into various subgroups.
We have the glycoproteins, somatomammotropins
and the proopiomelanocortin.
The glycoproteins will be important because
of certain similarities between the hormones
that have become really important to us and
I’ll point those out to you here and I’ll
keep reinforcing it throughout the entire
Somatomammotropins, we talked about these
being growth hormone.
There is one placental hormone that we’ll
refer to that behaves like a growth hormone
that becomes very important to us.
So, what’s important as we go through these
three structural types of your anterior pituitary
hormones is where is all the sharing of the
hormones taking place and what does that mean
Let’s first take a look at glycoproteins.
What I’ll point out to you here in this
picture are those specific glycoproteins that
are important to you so that you notice as
to where the sharing will be taking place.
What I mean is the following.
I’d like for you to first identify beta
You see it.
It stands for beta human chorionic gonadotropin.
What does that mean to you?
Well, you already know that that is something
that is being released by a placental counterpart
and when you do a pregnancy test, of course,
you are always looking for beta HCG.
Okay, well, if beta HCG has been released
by the placenta and your female, in fact,
is pregnant, beta HCGs then works on a couple
of other or behaves like a couple of hormones
that become incredibly important for it to
function properly and those are the following.
I want you to focus upon beta HCG, I want
you to think of a pregnant woman, I want you
to think about the foetus and the placenta.
Are you there?
Next, well, in order for that foetus to develop
within the uterus, a very important hormone
that it requires so that it receives proper
nourishment for growth and development is
Next, hmm, well, where is the foetus in the
first, let’s say, eight weeks getting the
The first eight weeks, there is absolutely
no way that the foetus is going to be producing
its own progesterone, right?
But, it sure as heck through the placenta
will be producing beta HCG and in addition,
in the ovary, what did you leave behind?
Remember, in the first eight weeks in the
ovary, you have an empty follicle and that
empty follicle is called what?
What do you call that corpus luteum?
Because that entire “empty follicle” is
filled with the luteinizing hormones, right,
where it’s covered by luteinizing hormones.
So, therefore, that corpus luteum is responsible
for secreting the progesterone that the foetus
requires oh so desperately, the beta HCG.
Next, identify the LH here; is going to act
upon the LH receptors and you have a nice
sort of symbiotic relationship between the
foetus and the maternal corpus luteum.
You’ve seen this in physiology in menstrual
If you don’t know your menstrual cycle,
I would highly recommend that you go back
and take a look at the menstrual cycle before
we further go on with discussions in endocrinology,
especially by the time we come to female repro,
Wow, it’s interesting too is that beta HCG
which is found in the first eight weeks or
so can also behave like another hormone and
it can behave like TSH...
TSH, it can.
And how important is thyroid hormone for the
Well, let me put it this way.
If the foetus didn’t have thyroid hormone,
what’s the pathology called?
So, the foetus has to have thyroid hormones
at all times and my goodness, that foetus
will make sure that this happens.
How does that occur?
Well, it’s a fact that you have beta HCG
which then works on your TSH receptors so
that it gives itself proper amounts of thyroid
hormones always so that cretinism does not
Is that clear?
It’s important that you pay attention to
The similarities between beta HCG and LH and
beta HCG and TSH and at some point later on,
in female reproductive pathology, we’ll
talk about our gestational diseases, we’ll
talk a lot about human chorionic gonadotropin,
And all of these will play a role again and
again and again.
Let’s take a look at the next structural
type, it’s a somatomammotropin.
Remember, I told you to pay attention to the
So, this does not mean inhibitory; in fact,
it means what?
Promotion or promoting or secreting-secreting,
Okay, now, we have growth hormone and this
time, we have another placental hormone.
This is called prolactin.
So, growth hormone prolactin from the anterior
pituitary will play a role… they will…
are together known as somatommamotropins and
especially, if you’re thinking about during
development, once again a pregnant woman,
obviously growth hormone will be playing a
role as will be prolactin, especially in the
female because it’s responsible for milk
And you know that as well because if there’s
excess prolactin, which is a huge topic for
us in endocrine pathology, then you know there
Let’s go to the foetus and the placenta.
We have a placental hormone here called human
Do not confuse this with human chorionic gonadotropin.
Whatever you do, one has nothing to do with
Both have huge clinical applications.
Let’s talk about human placental lactogen.
Let’s go back to the foetus again and the
placenta, but this time, instead of ensuring
that the foetus has sufficient amounts of
progesterone and sufficient amounts of thyroid
hormones with the help of what placental hormone
Human chorionic gonadotropin, this time we
have human placental lactogen.
What does this ensure that the foetus is receiving?
Hmm, doesn’t the foetus require glucose?
Tell me about glucose.
It crosses the blood placental barrier, that
Glucose passes through a lot of barriers,
it has to, ha-ha, so that you can properly
nourish the target in front of you.
So, therefore, human placental lactogen behaves
like a growth hormone, especially in the mother
in which it renders insulin receptors resistant.
What did I just say?
The human placental lactogen from the foetus
then works upon the insulin receptors of the
mother rendering it resistant so that the
mother cannot take up the glucose, right?
So then who is guaranteed the glucose?
Our third and final structural type will be
You focus upon the last two portions of this.
Melanocortin pretty much tells you everything
that you need to know about your specific
Mm-hmm, watch this.
The cortin is going to refer to ACTH from
the anterior pituitary.
What about the melano?
Hold on, I’ll show you when you’ll be
using melano, but I’m sure that you already
know as to what I am referring to.
Now, the proopiomelanocortin, POMCs, ACTH,
lipotropins, MSH and beta-endorphins, all
of these are important in one... in some way,
shape or form.
ACTH, for obvious reasons.
Now, melanocytes stimulating hormone, MSH,
is incredibly important.
Let’s say I might as well give you the pathology.
Your patient is suffering from the following
- has decreased blood pressure, is failure
to thrive even and in addition to that, you
take a look at the patient around the oral
mucosa and you find hyperpigmentation around
the oral mucosa.
What am I referring to here and what’s your
next step of management?
With that type of clinical presentation, no
doubt I am referring to what’s known as,
well, upon CT, they’ll make it a little
bit easier, but then abdominal CT and you
find that the adrenals are atrophic.
In other words, I’m referring to primary
adrenal insufficiency a.k.a. Addison’s disease,
Decreased blood pressure I said, I said their
failure to thrive because, huh, there is no
cortisol and that’s going to kill your patient...
failure to thrive and I said around the oral
mucosa, there was hyperpigmentation.
What’s going on here?
If there is no cortisol, primary adrenal insufficiency.
Then what hormone is elevated in your patient?
Where did it come from?
M, Melanocytes stimulating hormone; corticotrophin
So, therefore, that elevated level of melano
is going to give you your pigmentation.
You also have beta-endorphins.
Endorphins make you feel good and hopefully
by going through medicine, you are feeling
good about what you’re learning.
I want your endorphins to be kicking in.
Welcome to POMC.
Now, there’s a little bit more detail here
than is necessary, but I like for you to focus
That top runk[ph] that you’re seeing there
is proopiomelanocortin, POMC precursor.
That entire segment that is then broken up
into your ACTH and beta endorphin and then
you have your MSHs and MSH stands for melanocytes
stimulating hormone and the endorphin that
you want to know is your beta-endorphins and
of course, your ACTH.
These are the three structures that you want
to take out of your POMC segment and therefore,
giving you your pathologic... well, not just
pathologic, pathologic and physiologic presentations
of your patient based on the circumstances.
We talked about Addison’s, we talked about
ACTH works upon the adrenal cortex.
You have two different types of… three different
types technically of your MSH, you focus upon
the beta and the alpha-MSH and at times may,
may be referred to as an appetite suppressant,
especially the alpha and the beta endorphins
of course referring to your opioid peptides.