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Enterochromaffin Cells of the Small Intestine
Vol. 53, No.5
GA STROF.NTEROLOGY
Copyrigh t© IDG7 by T he Williams & Wilkins Co .
J>riult'd 'in U.S.A .
ENTEROCHROMAFFIN CELLS OF THE SMALL INTESTINE AMADon GONZALEZ-A NGULO,
M.D.,
ELENA YABun, AND
Lurs
LANDA,
M..D.
Sections of Elect1·on Microscopy and Gastroente1·ology, Hospital Geneml del Centro Medico Nacional, Ins tit1tto Mexicano del Seg?l.ro Social, Jl!lexico City, Mexico
It has repeatedly been stated that enterochromaffin (argentaffin) (Kulchitzky) cells of the small intestine are disposed in a solitary fashion between the other cells of the crypt of Lieberklihn, having a triangular shape without contiguity with the crypt lumen. 1 • ~ In a review on electron microscopy of the small intestine which appeared in 1965, Trier and Rubin stated that these cells do not reach the intestin al lumen and have no mi crovilli. 3 It is our purpose to point out that argentaffin cells of the sm all intestine do r each the intestinal lumen as seen with the electron microscope. As far back as 1942, in Maximow and Bloom's Textbook of Histology, it is stated that, from the argentaffin cell, a constricted continuation extends toward the lumen. These cells were illustrated in a drawing. 4 Rubin et al. in 1966 d escribed argentaffin cells extending to t h e crypt lumen ; however, the illustrations of su ch cells in cluded no electronmicrogra phs.5 While examining several biopsies of various disease processes affecting the small and large intestines, we have observed in the small intestine of a case of pellagra (where no a lterations were seen in the crypt) several granular cells which were columnar in s h ape and had distinct and orderly microvilli of the type characteristic of intestinal cells. A close examination of t hese cells revealed numerous electron dense granules measuring from 0.2 to 0.3 p. in largest diameter. The granules w ere almost exclusively located beneath the nucleus, between this and the basal plasma
membrane, a nd , only occasionally, these were seen between the nucleus a nd the lateral plasma membranes (fig. 1). Higher magnification of the granules of several cells disclosed a central osmiophilic core surrounded by a clear halo bounded by an osmiop hilic agranular thin m embrane (fig. 2). This picture is characteristic of argentaffin cell granules as described elsewhere.6 The apical half of these cells disclosed few organelles. The mitochondria were small and round, and the ergastoplasm was r epresented by free ribosomes. The in tern a l membrane system w as poorly developed . Occasionally seen were multivesicular bodies such as the one illustrated in figure 3. The lateral plasma membranes pursued a straight course similar to that seen in undifferentiated crypt cells. The junctiona l complex appeared the same. Unlike undifferentiated crypt cells, the fil aments originating in the cores of the microvilli did not seem to penetrate in to the apical cytoplasm (fig. 3). As a result of these observations we believe that the argentaffin cell of the small intestin e, like the rest of t he heterogeneous cell population of the crypt, is in fact a columnar cell which also h as microvilli. In the stomach, argentaffin cells with clear cu t microvilli have been observed reaching the gastric lumen.U-8 In the small in testine the scar ce number of these clements, the plane of section, and the concentration of their granules at their base as rea dily seen with the light microscope exp la in the widespread assumption Received F ebruary 14, 1967. Accepted June 16, that these cells are triangular with their 1967. apex toward, but not reaching, the lumen Address requ es ts for reprints to : Dr. Amador of the in testin e. It is likely t hat these cells GonziUez-Angulo, Hospital General de l Centro may have the same origin as the rest of Medico Nacional, Institu to Mexicano del Seguro Social, Cuauhtemoc 330, Mexico 7, D .F., M exico . the mucosa l cell population. 745
Fw. 1. Electromicrograph of enterochromaffin cell of an intestinal crypt. Note the dense population of osmiophilic round to oval granules (arrows) characteristic of these cells. The apical cytoplasm reaches the crypt lumen and shows microvilli (MV). (X 9724) Verona! acetatebuffered osmium fixation. Uranyl acetate and lead citrate staining. Philips EM-200.
N ovembeT 1967
EN 1'EIWCH1WMA FFIN CEL LS
Fw. 2. Dense osmiop hilic granules, presumably sr'ereto ry in na ture , of an enterochmmnffin cell of the intestina l crypt. The granules show an elcr:tron den se co re surmnnded by a clear halo (arrows ) (X 42,840) . Veron a! :wctat
747
748
GONZALEZ-ANGULO ET AL.
Vol. 53, No. 5
REFERENCES 1. Ham, A. W. 1965. Histology, Eel. 5, p. 694-695.
J . B. Lippincott Company, Philadelphia. 2. Rubin, W., L. L. Ross, G. H. Jeffries, and M. H. Sleisenger. 1966. Intestinal heterotopia . A fine structural study. Lab. Invest. 15: 1024-1049. 3. Trier, J. S., and C. E. Rubin. 1965. Electron
microscopy of the small int estine. A review. Gastroenterology 49: 574-603. 4. Maximow, A. A., and vV. Bloom. 1942. A textbook of histology, Ed. 4, W. B. Saunders Co., Philadelphia and London, .409 p. 5. Rubin, W., L. L. Ross, M. H. Sleisenger, and E. Weser. 1966. An electron microscopic study of adult celiac disease. Lab. Invest. 15: 1720-1747. 6. Fawcett, D. W. 1966. An atlas of fine structure, pp. 274-275. vV. B. Saunders Company, Phil-
adelphia. 7. Luse, S. A., and P. E. Lacy. 1960. Electron
microscopy of a malignant argentaffin tumor. Cancer 13: 334-346. 8. Ito, S., and R. J. Winchester. 1963. The fine structure of the gastric mucosa in the bat. J. Cell. Biol.16: 541-578.
Fro. 3. Apical half of enterochromaffin cell shown in figure 1. Note that the junctional complex in lateral plasma membranes (arrows); a multivesicular body (mb), a centriole (c), and ribosomes ( r ) are readily seen. X 32,500. Verona! acetate-buffered osmium fixation. Uranyl acetate and lead citrate staining. Philips EM-200.
GA STROF.NTEROLOGY
Copyrigh t© IDG7 by T he Williams & Wilkins Co .
J>riult'd 'in U.S.A .
ENTEROCHROMAFFIN CELLS OF THE SMALL INTESTINE AMADon GONZALEZ-A NGULO,
M.D.,
ELENA YABun, AND
Lurs
LANDA,
M..D.
Sections of Elect1·on Microscopy and Gastroente1·ology, Hospital Geneml del Centro Medico Nacional, Ins tit1tto Mexicano del Seg?l.ro Social, Jl!lexico City, Mexico
It has repeatedly been stated that enterochromaffin (argentaffin) (Kulchitzky) cells of the small intestine are disposed in a solitary fashion between the other cells of the crypt of Lieberklihn, having a triangular shape without contiguity with the crypt lumen. 1 • ~ In a review on electron microscopy of the small intestine which appeared in 1965, Trier and Rubin stated that these cells do not reach the intestin al lumen and have no mi crovilli. 3 It is our purpose to point out that argentaffin cells of the sm all intestine do r each the intestinal lumen as seen with the electron microscope. As far back as 1942, in Maximow and Bloom's Textbook of Histology, it is stated that, from the argentaffin cell, a constricted continuation extends toward the lumen. These cells were illustrated in a drawing. 4 Rubin et al. in 1966 d escribed argentaffin cells extending to t h e crypt lumen ; however, the illustrations of su ch cells in cluded no electronmicrogra phs.5 While examining several biopsies of various disease processes affecting the small and large intestines, we have observed in the small intestine of a case of pellagra (where no a lterations were seen in the crypt) several granular cells which were columnar in s h ape and had distinct and orderly microvilli of the type characteristic of intestinal cells. A close examination of t hese cells revealed numerous electron dense granules measuring from 0.2 to 0.3 p. in largest diameter. The granules w ere almost exclusively located beneath the nucleus, between this and the basal plasma
membrane, a nd , only occasionally, these were seen between the nucleus a nd the lateral plasma membranes (fig. 1). Higher magnification of the granules of several cells disclosed a central osmiophilic core surrounded by a clear halo bounded by an osmiop hilic agranular thin m embrane (fig. 2). This picture is characteristic of argentaffin cell granules as described elsewhere.6 The apical half of these cells disclosed few organelles. The mitochondria were small and round, and the ergastoplasm was r epresented by free ribosomes. The in tern a l membrane system w as poorly developed . Occasionally seen were multivesicular bodies such as the one illustrated in figure 3. The lateral plasma membranes pursued a straight course similar to that seen in undifferentiated crypt cells. The junctiona l complex appeared the same. Unlike undifferentiated crypt cells, the fil aments originating in the cores of the microvilli did not seem to penetrate in to the apical cytoplasm (fig. 3). As a result of these observations we believe that the argentaffin cell of the small intestin e, like the rest of t he heterogeneous cell population of the crypt, is in fact a columnar cell which also h as microvilli. In the stomach, argentaffin cells with clear cu t microvilli have been observed reaching the gastric lumen.U-8 In the small in testine the scar ce number of these clements, the plane of section, and the concentration of their granules at their base as rea dily seen with the light microscope exp la in the widespread assumption Received F ebruary 14, 1967. Accepted June 16, that these cells are triangular with their 1967. apex toward, but not reaching, the lumen Address requ es ts for reprints to : Dr. Amador of the in testin e. It is likely t hat these cells GonziUez-Angulo, Hospital General de l Centro may have the same origin as the rest of Medico Nacional, Institu to Mexicano del Seguro Social, Cuauhtemoc 330, Mexico 7, D .F., M exico . the mucosa l cell population. 745
Fw. 1. Electromicrograph of enterochromaffin cell of an intestinal crypt. Note the dense population of osmiophilic round to oval granules (arrows) characteristic of these cells. The apical cytoplasm reaches the crypt lumen and shows microvilli (MV). (X 9724) Verona! acetatebuffered osmium fixation. Uranyl acetate and lead citrate staining. Philips EM-200.
N ovembeT 1967
EN 1'EIWCH1WMA FFIN CEL LS
Fw. 2. Dense osmiop hilic granules, presumably sr'ereto ry in na ture , of an enterochmmnffin cell of the intestina l crypt. The granules show an elcr:tron den se co re surmnnded by a clear halo (arrows ) (X 42,840) . Veron a! :wctat
747
748
GONZALEZ-ANGULO ET AL.
Vol. 53, No. 5
REFERENCES 1. Ham, A. W. 1965. Histology, Eel. 5, p. 694-695.
J . B. Lippincott Company, Philadelphia. 2. Rubin, W., L. L. Ross, G. H. Jeffries, and M. H. Sleisenger. 1966. Intestinal heterotopia . A fine structural study. Lab. Invest. 15: 1024-1049. 3. Trier, J. S., and C. E. Rubin. 1965. Electron
microscopy of the small int estine. A review. Gastroenterology 49: 574-603. 4. Maximow, A. A., and vV. Bloom. 1942. A textbook of histology, Ed. 4, W. B. Saunders Co., Philadelphia and London, .409 p. 5. Rubin, W., L. L. Ross, M. H. Sleisenger, and E. Weser. 1966. An electron microscopic study of adult celiac disease. Lab. Invest. 15: 1720-1747. 6. Fawcett, D. W. 1966. An atlas of fine structure, pp. 274-275. vV. B. Saunders Company, Phil-
adelphia. 7. Luse, S. A., and P. E. Lacy. 1960. Electron
microscopy of a malignant argentaffin tumor. Cancer 13: 334-346. 8. Ito, S., and R. J. Winchester. 1963. The fine structure of the gastric mucosa in the bat. J. Cell. Biol.16: 541-578.
Fro. 3. Apical half of enterochromaffin cell shown in figure 1. Note that the junctional complex in lateral plasma membranes (arrows); a multivesicular body (mb), a centriole (c), and ribosomes ( r ) are readily seen. X 32,500. Verona! acetate-buffered osmium fixation. Uranyl acetate and lead citrate staining. Philips EM-200.