Class notes
Sex Steroids
- Course
- Institution
University of Edinburgh Lecture notes for Reproductive Biology 3 Lecture "Sex Steroids"
[Show more]
Seller
Follow
alexgpegg
Reviews received
Content preview
Sex Steroids Steroids regulate endocrine function
o Steroids are lipid soluble meaning they can move across membranes
o They have an effect on many different parts of the body
Different types of steroid hormones
o Glucocorticoids- increase protein turnover and gluconeogenesis
o Mineralocorticoids- control sodium and potassium balance in the body
o Androgens- maintain functional activity of male reproductive system, anabolic
and sexual behaviour actions
o Progestagens- maintenance of pregnancy
o Oestrogens- maintain functional activity of female reproductive system, also
acts on cardiovascular system and bone
Steroids have effects on many tissues
Steroids are complex molecules
o Have multiple enzyme pathways
o Depend on the availability of substrates
o Depend on interconversion between active and inactive forms
o Have multiple signalling pathways
o They have multiple receptor types and distinct molecular pathways
o Bioavailability of the steroid for its receptor- actions of binding proteins
98% of steroid hormones are not available to bind to their cognate receptors
o Can synthesise steroids through different routes
Depends what enzymes are available
Steroids can be generated in different ways in different parts of the body
There are four key reproductive steroid hormones
o Progesterone
o Testosterone
o DHT
o And Oestradiol
Male sex hormones are needed to make female sex hormones
Progesterone is converted to 17α-hydroxy progesterone by 17α-
hydroxylase
17α-hydroxylase is converted to androstenedone by 17,20 lyase
Androstenedone is converted to testosterone by 17β-HSD
Testosterone is converted to oestrogens by aromatase
,
Control of the human menstrual cycle
o In first half of cycle follicles make steroids (oestrogen)
o In second half of cycle, corpus luteum makes steroids (progesterone)
o The receptive state is the period in the menstrual cycle where implantation can
occur
o Oestrogen stimulates the endometrium to develop
o
Thecal cells and granulosa cells work together to produce oestradiol
o Thecal cells are found outside the follicle
o Granulosa cells found on the inside of the follicle
o Need combination of enzymes from both cells to make oestradiol
Granulosa perform the most aromatisation
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller alexgpegg. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.53. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67163 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now