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| Lars
Choritz |
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Home
Institution
Freie Universität Berlin (Charité Universitätsmedizin Berlin)
Host
Institution(s)
Department of Ophthalmology and Visual Science, Yale University, New Haven
Mentor: Miguel Coca-Prados, Ph.D.
E-Mail:
LarsChoritz@hotmail.com
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Research
Topic
see Abstract |
Personal
Reactions to the U.S. Experience
This hasn't been my first visit to the US and I think it's safe to say that
it won't be my last one, either. So far it has been a tremendously rewarding
experience for me. I met a bunch of great people, both at the lab and outside
of it, learned lots about the US in general, about research in the US, about
scientific and medical English, and, best of all, about myself. And I simply
had fun. What more is there to say? |
Greatest
Difficulties Encountered
As mentioned I've spent quite some time in the US before, so I didn't run
into any real problems this time. I found a place to stay over the internet,
and my roommate turned out to be great. I had no problems with any of the
bureaucratic issues, ran into no difficulties with the language, didn't
experience any form of culture shock or similar hassles. So far it's going
almost too well. I'm still waiting for something to go terribly wrong...
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Most
humorous incident
There are many to choose from, most of them hard to relate because of their
situational nature and because they often require intimate knowledge of
the people involved. Definitely very memorable were my first attempt at
skiing, the alienation of a dog from it's owner (a friend I visited over
Christmas), dressing up for Halloween, and countless conversations with
my colleagues at the lab. There is hardly a day that goes by without laughter.
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Helpful
Hints for Future Students
- Start
your paper work early on.
- Bicycles
are really cheap over here, but be careful on the roads. People are
not used to bicycles being a part of traffic...
- Even
if you don't want to drive a car, most states offer a "non-drivers"
license. It's the best means of identification, doesn't cost much, fits
into any wallet, and saves you the trouble of taking your passport along
all the time...
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Abstract
on Research Topic
The
Role of Natriuretic Peptides in Regulating Aqueous Humor Formation in Glaucoma
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Author:
Lars Choritz
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Institution:
Department of Ophthalmology and Visual Science, Yale University, New Haven,
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| CT
Note: Because of possible interferences with ongoing experiments and
submitted results, this abstract does not reflect one special project and
should give a more overall idea of the work done by my host laboratory.
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Purpose:
To establish the mechanisms by which natriuretic peptides decrease aqueous
humor production and to further characterise the ciliary epithelium in different
species and thereby to identify potential drug targets for the treatment
of primary open-angle glaucoma. |
Materials
and Methods:
Cattle, rat and mouse eyes are dissected and pieces of the ciliary body
are extracted. The intact tissue is mounted into a chamber on the table
of a microscope and incubated with fluorescent dyes for either protons (BCECF),
chloride ions (MQAE) or calcium ions (Fluo-3). After incubation the dye
is excited with light at specific wavelengths and emits light of a different
wavelength, which is detected by a camera. The intensity of the emitted
light correlates to the concentration of the target ion which allows to
monitor changes in intracellular ion concentrations after stimulation or
inhibition of specific receptors. |
Results:
The rate of pH-recovery after acidification of the non-pigmented epithelial
(NPE) cells is significantly inhibited by the different natriuretic peptides
in a dose-dependent manner. Similar results can be obtained using cGMP analogues.
Inhibitors of NP-receptors as well as gap junction blockers attenuate the
effect. Inhibition of other transporters, that are know to influence the
Na+/H+-Exchanger (NHE), have no effect on the recovery rates. Chloride measurements
have not yet yielded conclusive results. |
Conclusion:
Natriuretic peptides (NP's) as well as specific NHE inhibitors decrease
intraocular pressure. Our research indicates that the NP's may achieve this
through inhibition of NHE in NPE cells of the ciliary epithelium. Whether
(and which) other membrane-bound transporters are involved in this process
remains to be determined. The above mentioned results open up the possibility
of regulating other proteins through changes in intracellular pH as well
as cell volume and concentration of cGMP. |
