Nutritional Secondary Hyperparathyroidism in the Horse

(10 Lxpcrimental Nutritional Sccondary ~lypcrparathyroidism in the I lorse , . .
irregular flakes, often pushed toward the periphery. Clear irregular
areas were left in the cytoplasm after such coalescence of the basophilic
material. At this stage the juxtanuclear bodies were much more
frequent in the intermediate cells than in the light chief cells. Two,
three, or even more bodies could be present in the cytoplasm. Some-
times they were actually located next to the nucleus, but their distribu-
tion was quite haphazard. They were often located next to the cell
membrane. In cells more definitely of the water-clear types, the baso-
philic material was further pressed together and appeared to be glued
to the cell membrane. It gave a false impression of a very thick cell
membrane. With the cytoplasm otherwise empty the very frequent
juxtanuclear body or bodies stood out well (Fig. 26).
Table XX (for analysis see Appendix, Table IV) shows that the
nuclear surface of the light chief cells varied significantly in the NStl
horses. As there were no significant differences in the cytoplasm to
nuclear ratios, it can therefore be concluded that the degree of hyper-
trophy of the parathyroids varied in the NSH horses.
Epithelial fat was not demonstrated in the parathyroids of NSH
horses or of the control.
The diagnosis to be applied to the changes in the parathyroid
glands of NSH horses requires some analysis. As shown in Table XIX,
the glands were grossly enlarged. There were no differences in the
relative amounts of interstitial tissue including embryologic rudiments.
/,/,q. 27. I’arathyroid, coiitrol. Jmgc area of interstitial fat. hlostly light chief cells;
area of dark chief cell (in front of arrovrr). El & E, x 80.
/;(’. 24. I’arathyroid, NSIH 2. Interstitial fat spaces rcplaccd by parcmcliynia
consisting mainly of light chief cells ; areas of watcr-clcar cells (arrows). Abund;uit
capillary network. 1-1 h E, x 80.
1;i.r. 25. l’arathyroid, NSIH 1. I.ight chief cells in upper left third of picture;
otherwise water-clear cells. Coalcsccncc of cytoplasmic RNA with flakes in
cytoplasm (long arrow) or glued to the cell mcmhranc (short arrolv). 1-1 & E, oil
itnmcrsion, Y 720.
f(q. 26. I’arathyroid, NSI-1 2. Nurncrous justanuclcar bodies \\.it11 haphazard
distribution: at short thin arrow nest to the nucleus; at incdiuni short thin arro\\.
in the middle of the cytoplasm; at long thin arro\y at thc cell membrane. At
straighi thick arrow intcrmcdiatc stage Ixtwccn light chief acid \i,:itcr-clc:ii- cell :
at curved arro\r water-clear ccll. Crcsylccht violet, x 450.
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