StudentShare
Contact Us
Sign In / Sign Up for FREE
Search
Go to advanced search...
Free

Steroidogenesis Has a Common Pathway but Hormonal Steroids Are Secreted in a Specific Manner - Essay Example

Cite this document
Summary
From the paper "Steroidogenesis Has a Common Pathway but Hormonal Steroids Are Secreted in a Specific Manner", it is clear that steroidogenesis is the synthesis of steroidal hormones from cholesterol. Cholesterol is a sterol derived from the steroid nucleus. …
Download full paper File format: .doc, available for editing
GRAB THE BEST PAPER98% of users find it useful
Steroidogenesis Has a Common Pathway but Hormonal Steroids Are Secreted in a Specific Manner
Read Text Preview

Extract of sample "Steroidogenesis Has a Common Pathway but Hormonal Steroids Are Secreted in a Specific Manner"

Steroidogenesis takes place in endocrine glands like the adrenal and gonads.P450side chain-linked cleaving enzyme gets involved in the interconversion of cholesterol to Carbon18, Carbon19, and Carbon21 and this is the committed step of Steroidogenesis (John 1994, p.33).

            HMG-CoA or the mevalonate pathway generates isopentenyl pyrophosphate and dimethylallyl pyrophosphate which serve as precursors for steroidal hormones biosynthesis. Isopenteyl pyrophosphate and dimethylallyl pyrophosphate become joined forming geranyl pyrophosphate that becomes lanosterol (Mary 2011, p.55). Lanosterol undergoes Steroidogenesis transformation to form other steroids. All steroid hormones in humans follow this pathway, but not all steroids are hormones (John 1994, p.77).

            Steroid hormones are crucial for the proper functioning of the body. They get synthesized from cholesterol which is also a component of the cell membrane thus the hormone is able to enter the cell and bind to its receptor. Steroid hormones get classified as androgens, estrogens, progestins, mineral corticoids, and glucocorticoids. Both estrogens and androgens get generated by the gonads and affect sexual development. Progestins mediate the menstrual cycle and pregnancy. Excretion of water and salts by the kidney get regulated by mineral corticoids while lipid carbohydrate and protein metabolism become affected by glucocorticoids. Steroid hormones become synthesized when they are needed. The brain releases a signal when the body wants a certain protein synthesized or needs a certain process done (John 1994, p.78). These signals get transmitted via the intermediary hormones in other words through trophic hormones. Once released, they act on the central nervous system and the peripheral target tissues (Richardb2010, p.67).

One can regulate the amount of steroid hormone secretion by regulating the amount of cholesterol produced because cholesterol is the precursor for these hormones. The adrenal cortex has three main tissue regions: the zona glomerulosa, zona fasciculate, and zona reticular area. These zones are histological and enzymatically distinct and the exact steroid hormone secreted depends on the enzymes present (Reginald 2010, p.34). Adrenocorticotropin (ACTH) hormone regulates hormones produced at the zona reticularis and zona fasciculata (Donald 2010, p.56). The hypothalamus releases ACTH into the bloodstream then it becomes carried to the adrenal glands where it binds to ACTH receptors on the cell membrane activating adenylate cyclase with the production of cAMP (second messenger). This leads to the ultimate secretion of cortisol. When the body needs to accumulate more sodium, angiotensinogen gets released from the liver and it becomes angiotensin( i) and later angiotensin (ii) that bind to the cell membrane receptors which get coupled to the phospholipase c of the zona glomerulosa (John 1994, p.32). This leads to the secretion of aldosterone; a mineral corticoid. Aldosterone leads to sodium retention by facilitating gene expression of messenger RNA for sodium-potassium ATPase which is responsible for the reaccumulation of sodium and potassium.

Gonadol steroid hormones become secreted by the testis and ovaries. The important hormones in this category are estradiol and testosterone. Luteinizing hormone stimulates testosterone production in men by binding to Leydig cells. Androgen binding protein transports testosterone Sertoli cells which convert it to dihydrotestosterone which is more potent. Androgen binding protein production gets increased by Follicle-stimulating hormone (FSH). Luteinizing hormone in females binds to ovary thecal cells stimulating the secretion of testosterone and androstenedione. Aromatase complex converts the latter two hormones into estrogen (John 1994, p.88).

            All steroidal hormones share a common biosynthesis pathway that involves cleavage of a six-carbon group from the precursor (cholesterol) by p450 side chain linked cleaving enzyme as the rate-limiting step. They all use cholesterol as their precursor however, they get secreted in a strongly cell-specific manner. The adrenal cortex has three zones with cells that are histologically distinct and each zone produces a different type of steroidal hormone. Each zone has different receptors on the cell membrane that anchor specific tropic hormones (John 1994, p.68).

Read More
Cite this document
  • APA
  • MLA
  • CHICAGO
(“Steriodogenesis has a common pathway but hormonal steriods are Essay”, n.d.)
Steriodogenesis has a common pathway but hormonal steriods are Essay. Retrieved from https://studentshare.org/biology/1449981-steriodogenesis-has-a-common-pathway-but-hormonal
(Steriodogenesis Has a Common Pathway But Hormonal Steriods Are Essay)
Steriodogenesis Has a Common Pathway But Hormonal Steriods Are Essay. https://studentshare.org/biology/1449981-steriodogenesis-has-a-common-pathway-but-hormonal.
“Steriodogenesis Has a Common Pathway But Hormonal Steriods Are Essay”, n.d. https://studentshare.org/biology/1449981-steriodogenesis-has-a-common-pathway-but-hormonal.
  • Cited: 0 times

CHECK THESE SAMPLES OF Steroidogenesis Has a Common Pathway but Hormonal Steroids Are Secreted in a Specific Manner

Biosynthesis of Peptide and Steroid Hormones

The peptide hormones are secreted from the cell of origin through exocytosis while, steroid hormones simply diffuse across the cell membrane.... Hormones are also classified on the basis of their chemical structures into steroids, peptides and amines.... Hormones are also classified on the basis of their chemical structures into steroids, peptides and amines.... At this stage, the cleavage of certain substrates of prohormone convertases occurs however, a major portion of post translational processing occurs in the trans-Golgi network or in the secretory pathway....
3 Pages (750 words) Essay

All Peptide Hormones After Cell Function by Phosphorylation, While Steroid Act by Altering Gene Expression

In order to recognize and decode a specific signal, the receiver requires prior information for that signal which has to be either obtained or is genetically fixed.... endocrine signaling involves the secretion of specific hormonal signals in the bloodstream which are then distributed to other parts of the body.... The first messenger molecule cannot pass through the target cell membrane but instead is bound by specific receptors.... The input signals allow conformational changes in the structure altering the specific protein functions and cellular activity....
5 Pages (1250 words) Essay

Risk and Benefit of Steroids

For instance, steroids such as androgens, estrogens, progestogens, anabolic, and catabolic have a specific function in the body.... These steroids are the basic units of several hormones, body constituents, and drugs.... Both natural and synthetic steroids are used to treat several disorders and play a critical role in the normal functioning of the body (Clear Lead Inc.... In general, steroid refers to a group of naturally occurring or synthetic fat-soluble organic compounds that has a structure based on a steroid nucleus - a hydrogenated cyclopentanoperhydrophenanthrene ring system (Figure 1)....
10 Pages (2500 words) Research Proposal

Safe Way of Anabolic Steroids Use

These artificial steroids are offshoot of testosterone (the male sex hormone).... The recent development of anabolic steroids is an amazing advancement.... It is incredible; the way anabolic steroids boost performance and increase stamina.... Since, these steroids try to be like male sex hormone that is why they are used for all the same purposes which are handled by testosterone in a male body. ... he core of anabolic steroids touches two overlapping effects; anabolic and androgenic....
8 Pages (2000 words) Essay

The effect of nitric oxide and cGMP on follecogenises

vulation disturbances are a common cause of subfertility in women (Snick et al.... hormonal balance governing the ovarian cycle is a critical factor in female fertility.... Several factors including stressful lifestyles, extremes in body weight, diet, certain hormonal diseases (e.... pituitary gland tumours) and endocrine disrupting chemicals, such as PCBs and some pesticides can impact a womans hormonal balance and, thereby, the ovulatory pattern (Farr et al....
40 Pages (10000 words) Essay

Effects of Steroids on Calcium-Activated Potassium Channels

The paper "Effects of steroids on Calcium-Activated Potassium Channels" states that the cod has different LH and FSH secreting cells and thus is an ideal model organism for these studies.... The effect of steroids on the secretion of the two hormones is dependent on the composition of CAPCs subtypes.... Apart from regulating gametogenesis, these hormones also control steroidogenesis, a process that produces sex steroids involved in moderating gametogenesis (Schulz and Goos, 1999)....
11 Pages (2750 words) Essay

Hormonal Secretion Peculiarities

Complex in the sense that their way of functioning needs a deep study to classify under specific nomenclature.... Synthesis, secretion, transport, binding to specific receptors and elimination are the steps involved in hormonal regulation.... They are - one hormone – many functions; one hormone - specific function and one function – many hormones.... For example, ACTH secreted by the anterior pituitary, although it circulates freely in the body, only acts on the adrenal glands because only the adrenal cortex has receptors to ACTH....
7 Pages (1750 words) Essay

Sex Hormone-Binding Globulin Gene

In these species, the SHBG homolog widely referred to as the androgen binding protein (ABP) is produced and secreted by Sertoli cells.... This gene encodes an amino-terminally truncated SHBG isoform which accumulates in the acrosome of sperm and subsequently binds to steroids in the same way as plasma SHBG.... As a result of its high affinity and selective nature towards sex steroids, the concentration of SHBG in human blood is the major determining factor of the number of free androgens and estrogens in target cells....
18 Pages (4500 words) Essay
sponsored ads
We use cookies to create the best experience for you. Keep on browsing if you are OK with that, or find out how to manage cookies.
Contact Us