Re: pituitary ("basophils" + 2 questions + thoughts)
|From:||"J. A. Kiernan" <firstname.lastname@example.org>|
On 19 Apr 2001, Peggy Wenk wrote a _superb_ essay on anterior
pituitary cell-types. If stars were awarded for Histonet
contributions, this one would deserve 5 gold stars out of 5!
A point possibly worth adding is that "basophil" may not be
a very good name. The reason can be seen in this excerpt:
> So if you want to differentiate acidophils from basophils, use a
> combination, such as a trichrome stain (Masson or Mallory or Montreal used
> to be favorites for these) or MSB (eg. aniline blue - brilliant crystal
All the dyes used in these trichrome methods are acid dyes; not a
basic one among the lot of them, and yet the traditional naming
system was derived from stains of this type and developed to a
fine art by Romeis in the early 1940s. (He recognized many more
cell-types than there are hormones.) The pituitary "basophils"
stain blue (with aniline blue), as does collagen. In the 1960s
and 1970s many workers in this field (especially in France) called
the cells "cyanophils" (meaning cells that stain blue). Did this
chromatically correct term ever gain general acceptance?
With the advent of more rationally derived staining methods for
glycoproteins in the late 1950s (such as oxidation-alcian
blue-PAS-orange G, and others) it became possible to identify
stainable cell-types for about 4 of the 6 classical adenohypophysial
hormones in the chromophil cells. The chromophobe problem (resting
or chucking out hormone as soon as it's been made?) was largely
resolved by EM studies in the 1960s. Antibodies to the hormones and
appropriate immunocytochemistry became available in the 1970s,
making it easy to see which cells contained which hormones. Methods
using dyes still make pretty sections, but immunostaining provides
easily understood and functionally significant information.
Is there still a place for a term such as "acidophil adenoma"
for an STH-secreting tumour that causes acromegaly and
bitemporal hemianopia? Surely the surgical or post mortem
material from a hormone-secreting pituitary tumour is always
examined immunohistochemically in these times, so why bother
with trichromes or the histochemical methods of the 1950s?
The tumour can be given a meaningful name such as
"somatotrophocytoma" or "growthormonoma." Cushing attributed
his now eponymous syndrome to a basophil adenoma. How much more
elegant to call it a "corticotrophocytoma," with the informal
alternative of "acthoma."
Probably these simple suggestions are old-hat. I stopped
keeping up with pituitary literature when Bibliographia
Neuroendocrinologica died for lack of American taxpayers'
money. But that's another story.
John A. Kiernan
Department of Anatomy & Cell Biology
The University of Western Ontario
London, Canada N6A 5C1
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