Among all the classes of my undergrad in Chemistry and Pharmaceutical Technology (…yes, I know, I used the fancy misleading translation of post 5), we were all sort of terrified attending a series of modules as the professor had the fame to be very tough and severe. Of course my opinion has changed as time went by (it sounds so childish to me now) and I do thank for having met such a kind of tough professors during my studies. Most likely some former students of mine would say the same thing about me and my courses of nutritional biochemistry…in any case, I sometimes recall images from those classes as he was one of the first guys who tried to make us understand that Research is not a kind of magic with spells and formulas – but it consists of a robust and reliable series of approaches that have to be reproducible in every part of the world according to the description we provide (and this is also known as the empiric experimentation and mathematical demonstration by Leonardo da Vinci, precursor of the most widely spread scientific approach generated by Galileo Galilei – Am I being parochial here?! Am I, am I ?!?)
So, how do I obtain those numbers that make me cheer (or be sorrow for most of the time)?!
Please, let me introduce you two (of the) main methods I have acquired so far, that have an important role in building up my pile of work…
From the initial pages of this blog you might recall that islets from pancreas release insulin in response to change in blood glucose. This phenomenon is called “secretion”.
To study secretion we use the islets outside of the pancreas and we put them in a different environment (thus we will say in vitro). To convince the islets to secrete insulin we accommodate them into a test tube and provide them with a solution of glucose during a defined amount of time – generally 30 minutes or one hour. Because this particular way does not involve any change of conditions during the time of performance, the technique is called static insulin secretion (static because it is a simple on/off situation).
If you think a little bit more about how our body works, well, it is everything but static!
So, you might realise that a static secretion is maybe the most convenient way to study insulin secretion, but sometimes it is not the most appropriate.
Here, at the Diabetes Research Group at King’s College London I have learnt how to design and perform experiments aimed at determining the response of islets to variable glucose concentration during time, a situation termed dynamic insulin secretion.
It represents the most fascinating part of my research; and although it is notably considered to be technically challenging and more demanding than static, believe me or not it creates addiction!
(if you don’t believe me please go and ask one of my crazy Spanish colleague that I keep fighting with to use the apparatus!!!)
But how does this (intriguing ?!?) method work?
It is still an in vitro technique, (thus outside of the body!): in an artificial way we are able to recreate the most suitable environment for the islets of Langerhans to “perform their magic” outside of a living organism, as they were into the organism itself.
The perifusion apparatus (as we friendly call it) consists of a series of independent chambers connected to various buffer reservoirs. Islets are loaded into the chambers where they continuously (remember it is dynamic!) receive a physiological buffer supplementation. This continuous supplementation enables the timed kinetics of insulin secretion to be determined in response to a potential stimulus.
If the static is an on/off situation, the dynamic secretion technique can determine whether an effect is acute (= short termed in action) or sustained for the duration of the treatment, and whether it is reversible or not.
So we profile islets’ capability to secrete insulin and we evaluate what stimuli, compounds, conditions can make the islets of Langerhans perform better or worse. It might sound banal but this is an important piece of work as it can help us understand the processes that take place in the complex mechanism of the pancreatic response to glucose.
If you remember the concept of antennae-signals expressed in one of the initial posts, this “profiling technique” coupled with the addition of a series of signaling molecules, allows us to understand the role of the antenna whose response we are trying to understand.
[And if I have raised a little bit of curiosity in you, well, shoot me an email and I will be more than happy to physically walk you through our facilities and experiments!]