GI Hormones: Gastrin

Hi everyone, so this is my first post in the series of GI hormones!

There are 2 families of GI hormones -

1. Gastrin family (Gastrin , CCK)

2. Secretin family (Secretin, glucagon, VIP, GIP)

Others - Motilin, Peptide YY, Substance P, Ghrelin, Guanylin

In this post, I'll be talking about one of the members of the gastrin family, gastrin itself! :D


⛔⛔GASTRIN⛔⛔

I. Produced by: 

■ G cells - enteroendocrine cells located in antral gastric mucosa.

II. Physiology of secretion:     

■ Acts via CCK-B receptor

■ Progastrin is cleaved to form 3 different residues :G 14, 17,34.

■ Sulfated and carboxylated forms also exist.

■ Amidated form is more stable.

■ G17 is principal form w.r.t. GI actions.

■ G34 has longer t1/2 than others.

■ Inactivated in SI, kidneys

III. Functions: 

■ Stimulates Gastric acid and Pepsin secretion

■ Trophic action - stimulates growth of mucosa of Gut.

IV. Regulation:

A. Factors that increase secretion of gastrin: 

■ Luminal:

- Amino Acids (Aromatic) in stomach 

- Distension

Because the job of this hormone is to bring about protein breakdown via pepsin and increase pH of the stomach, Hence it is released in response to protein and other contents entering the stomach. Tells the stomach it's time to do its job!

■ Neural:

- Vagal discharge as it secretes GRP at the postganglionic fibres.

Both sympathetic and parasympathetic fibres in gut are stimulatory (dual ANS stimulation).. What can we do about it?

■ Bloodborne:

- Epinephrine

- Ca2+

Calcium is a universal stimulant of motility and exocytosis from glands; epinephrine = dual ans stimultion.

Factors that decrease secretion of gastrin:

■ Luminal:

- Acid

- Somatostatin

Acid tells the G cell to shut up. There's enough acidity. No need for stomach to yap.

Somatostatin keeps all other hormones in check!

■ Bloodborne:

- Secretin family (Secretin, VIP, GIP, glucagon) (archnemesis)

Applied aspects of Gastrin:
■ Normal S. Gastrin levels = upto 100pg/ml
■ Hypergastrinemia:
- Pathological Increase (eg. Gastrin secreting tumor)
- Compensatory Increase (eg. Pernicious Anemia i.e. Type A Gastritis; due to destruction of    acid secreting cells compensation with increased  gastrin.)
■ Hypogastrinemia:
- Antral loss eg. Antrectomy, Achlorhydria.
- H pylori associated ulcers/gastritis may show hypogastrinemia, but association is not very clearly established. 

My next post will be on Zollinger Ellison Syndrome.  Excited? :D I know I am 😎

Hope you guys like it. 

~ A. P. Burkholderia

Strongyloides Stercaralis Notes And Mnemonics

Hey everyone!
These are microbiology  notes made by me =) Hope it helps you ☺

"Inception"- a real thing!

Hello!

Remember the movie, "Inception" starring Leonardo DiCaprio??? Loved it.. right? :D
OK. Let me recall it for you.. Leo's character interferes with other's dreams to implant new ideas in their minds. It was a trippy plot premise. But, not entirely a Sci-Fi!!!

So, now what if I say we could do 'inception' without the subject being aware of what is being learned... "Yes, it is possible in reality now", the scientists say.

Normal AST, ALT and ALP values mnemonic

Continuing the normal values mnemonic posts :D

Today's post is on liver enzymes!

Normal SGOT, SGPT and ALP values!

Immunization schedule notes and chart

Hello!
So in these notes, I write about type of vaccine, strain used for vaccine prepration, diluent, content, dose, route, site of vaccination,strength,  protective efficacy, protective duration, contraindications, complications, age limit and storage of vaccines and special points used in the Indian immunization schedule.

It's a nice summary for those studying pediatrics, preventive and social medicine, pharmacology, microbiology and medicine. 

Stay Awesome ☺

Step 2 CK: Interventions that lower mortality in STEMI and ACS

Hello!

For Step 2 CK, remembering things that lower mortality is essential. Here's a mnemonic for interventions that lower mortality in STEMI (ST elevation MI), NSTEMI (Non ST elevation MI) and UA (Unstable angina).

Gastrointestinal Stromal Tumors Mnemonic

Hi everyone !
So here is a post about a few important points on GIST I figured can be remembered in an easier way if you love the letter "C" ! G does look like a C :D

Uses of somatostatin and bromocriptine notes & mnemonics

Hey everyone!
These are pharmacology notes made by me =)

Olympics 2016 and the Zika

Hey Awesomites!!!

You all know the Olympics and Paralympics are on their way in August and September. Excited, aren't you? Woohhooooo! :D

Its taking place in Rio de Janeiro, Brazil this year. So if any of you or your known really plan to travel to Brazil for the Olympics and the Paralympics... You have to know about the current situation of Zika virus out there. Brazil, along with many surrounding countries of America, are experiencing an Outbreak of Zika Virus.

Forensic toxicology notes part - 3

These are my toxicology notes. Hope it helps you!

Forensic toxicology notes part - 2

These are my toxicology notes. Hope it helps you.☺

Instructions for new authors: How to post through blogger app

If you wanna be an independent author at Medicowesome, here's what you need to do:

Email me at medicowesome@gmail.com asking that you want to write for Medicowesome. I'll say yaay! Of course, yes! :D

Make a blogger account (blogger.com) using your Gmail account.

Send me your gmail address. I will send you an author invitation, you must accept it within 24 hours.

Forensic Toxicology notes part - 1

These are my toxicology notes. Hope  it helps you! 

Alkaptonuria notes and mnemonic

Today, Hari sent me his notes on Alkaptonuria.

Alkaptorr makes him think of helicopter! And he imagines a black ox sitting in it!

Alkaptonuria mnemonic

Diuretics and antidiuretics notes

Diuretics and anti-diurectics notes by Shubham. Isn't he plain awesome for sending his notes to us?

Treatment of acne mnemonic

Hello!

Here's a short post on acne.

Antimicrobials for treatment of acne mnemonic: ABCDE
Azelaic acid
Benzoyl peroxide
Clindamycin
Dapsone
Erythromycin

GnRH agonists, GnRH antagonists, uses and mnemonic

Hey guys!

Here are a few more notes by the one and only, Shubham Patidar! This time on dopamine, prolactin and GnRH :D

Potter Sequence

A sequence is where a single initial aberration leads to a series of anomalies in the body. The best example of a sequence is 'Potter Sequence'.

Conditions like renal agenesis, maternal hypertension lead to oligohydramnios. The amniotic fluid plays a role in the lung development in the second half of pregnancy & so, there is a higher incidence of pulmonary hypoplasia in such foetuses which is the main cause of their death.

Oligohydramnios leads to direct pressure of the uterine wall on the developing foetus leading to flattened nose, recessed chin & low set ears. This is Potter sequence- sequence here because the initial aberration- oligohydramnios leads to & explains all the changes occurring later.

Happy Sunday!

Metronidazole notes and mnemonic

These amazing notes on Metronidazole were written by Shubham Patidar!

Biotin deficiency mnemonic

Hello!

Here's an interesting case of vitamin deficiency you should read.

Biotin deficiency is rare. Nice to know for exams though. Soooo.. I made a mnemonic. Biotin reminds me of the comic character, Tin Tin!

Biotin mnemonic

Study group discussion: A case of vitamin deficiency

Here's a vignette that I found on USMLE forums:

A 20-year-old male patient is admitted to the hospital 6 months ago following a motorcycle accident resulting in a severe closed head injury. The man has experienced recurrent fungal skin infections resistant to treatment for 1 month and severe vomiting over the last 2 days. Review of the patient's records shows he was well before the injury. He now suffers severe permanent cognitive impairment and requires continuous high-dose phenytoin therapy to manage chronic debilitating tonic-clonic seizures. The patient is resting comfortably in no apparent distress. He is unable to converse coherently. Vital signs are normal. Physical exam is striking for nearly total alopecia. A periorofacial erythematous macular rash is present along with severe seborrheic dermatitis and several truncal ringlike lesions consistent with tinea corpus infection.

Select the most likely vitamin deficiency.

Answer Choices:

A. Vitamin A deficiency

B. Vitamin B12 deficiency

C. Vitamin C deficiency

D. Vitamin D deficiency

E. Vitamin E deficiency

F. Thiamine deficiency

G. Pyridoxine deficiency

H. Folate deficiency

I. Biotin deficiency