A Paper I READ

A paper I read(7)
CAROTID: WHAT ELSE DOES IT SENSE?

It is ,of course, the peripheral chemoreceptor most sensitive to hypoxia! It can also sense changes in pCO2 and pH. But evidence is accumulating to prove that it can sense blood glucose too! The frequency of action potentials in the afferent nerve from carotid body is suppressed by glucose administration. Hypoglycaemia indicud by insulin in carotid denervated rats is not restored in the way it is in normal rats.
Hypoxia stimulates typeI cells of carotid body to secrete neurotransmitters which bind to neurones closeby within the carotidbody and excite them. Glucose seems act in a similar manner. Culture of type I cells isolated from rat carotid body were used in this experiment. Cultures were supplemented with neurons from rat petrosal ganglion( Zhang et al J.Physiol 578:735-750, 2007). Perfusion of low glucose solutions led to excitation of neurons which could be inhibited by appropriate blockers of neurotransmitters. Moreover effects of hypoxia and hypoglycaemia seem to be additive. Slices of carotid body when superfused with low glucose solutions, secreted in creased amounts of neurotransmitters.

Yes Sir,

Logically speaking, sensing 'Glucose levels' by the carotid body makes sense.

We can understand that O2 has to be sampled by the oxygen regulating -mechanism of the body, before it is utilized by many cells (so the sampling may not give us a wrong data).

This same logic applies to Glucose as well.

It will always be effective if it is close to the heart or in a large blood vessel. Because that is the sample of blood which is going to get pumped to all organs in the body.

Good thinking! Thanks.

My dear sir, its ameging information..
I have one another doubt sir some scientists believe that stimulus for peripheral chemoreceptors are increase PCO2, decrease Po2 and decrease pH. But as the glomus cells are only take dissolve o2 thats why in anaemia chemoreceptors are not stimulated.Thatswhy recent concept omit this Po2..

dear sir ,
i read ur article reg the biceps exercise ,really it intresting, i would like to add up more reg this, we therapist in neuro rehabilitation programme use a technique called IRRIADATION TECHNIQUE - that is we strongly activate the particular muscle of un affected side(ask the pt to contract the muscle strongly and therapist resist it) by repeted training we can see the initiation of same muscle on the hemiplegic side. the comman explanation given is overflow of impulse fron higher centre

very interesting article sir.

Thanks a lot! JPR