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A cytochemical study of aminopeptidase activity in the rabbit epididymis
Life Sciences Vol . 6, pp . 1749-1751, 1967 . Printed in Great Britain .
Pergamon Press Ltd .
A CYTOCHEMICAL STUDY OF AMINOPEPTIDASE ACTIVITY IN THE RABBIT EPIDIDYMIS Birgitta Hellatröm and Lennart Nicander Department of Anatomy and Histology, Royal Veterinary College Stockholm 50, Sweden
(Received 22 May 1967)
A very high aminopeptidase activity has been histochemically demonstrated (1) in the epididymal head of many different mammals including rabbits . However, no information was given of the distribution of this activi ty between the efferent ductulea and the epididymal duct, or regarding the cytological localization of the activity . To receive information of these topics, aminopeptidase activity was studied in pieces from different parts of the rabbit epididymas, in fresh tissue and after fixation for one hour in 4% glutaraldehyde in phosphate buffer, pH 7 . 4 at 4 ° C . Sections were cut in a cryostate at 5 to 10 microns and enzyme activity was studied with L-alanyl4-methoxy-2-naphtylamide as a substrate (6) . The incubation time varied from 10 to 3~ minutes . Control material from the kidney cortex and the mucosa of the small intestine was studied simultaneously, as the luminar surfaces of ` ' these strongly absorbing epithelia are well known to show a very high aminopeptidase activity . Activity was never observed in any region of the epididymal duct . A marked activity was observed along the luminar surface of the non-ciliated cells of the efferent ductulea, very probably in their'microvillous border (Fig . 1) . The ciliated cells appeared to be negative . The control sections
1749
1750
AMINOPEPTIDASE ACTIVITY
FIG .
Vol . 6, No . 16
1
Portion of an efferent ductule of the rabbit fixed in glutaraldehyde . Aminopeptidase activity can be seen in the microvillous border of the nonciliated cells whereas the ciliated cells (arrows) appear to be negative . showed a very high activity in the brush border of the proximal kidney tubules and the striated border of the surface epithelium of the small intestine . Thorsteinseon (7), who found some di- and tripeptidase activity in the homogenized rabbit epididymis, mentioned the possibility that some activity was present in the epididymal plasma but ascribed most of the activity to the sperm cells . The present demonstration of aminopeptidase activity in the micro~illous border of the non-ciliated cells of the efferent ductules is in accordance with the relationship of these cells to the proximal tubule cells of the embryonic mesonephros and with the modern view, recently given support by physiological (2) and ultra structural (3, 4, 5) studies, that the efferent ductules have a marked resorptive function .
References 1.
L . ARVY, C . R . Acad . Sci .
254, 4202 (1962) .
2.
B . CRABO and B . GUSTAFSSON,
3
A . -F . HOLSTEIN, Z . Zeltforsch . 64, 767 (1964) .
J . Repr . Fert . ~ 337 (1964) .
Vol . 6, No . 16 4.
A. J
AMINOPEPTIDASE ACTIVITY
1751
LADMAN and W . C . Young, J. Biophys . Biochem. Cytol. 4, 219
(i958) . 5.
J. MARTAN, Z . HRUBAN and A. SLESERS, J. Morph. 121, 81 (1967) .
6.
B . MONIS, H. WASSERKRUG and A. M. SELIGMAN, J. Hietochem.
7.
Cytochem . ~ 503 (1965) .
T, THORSTEINSSON, Am . J Physiol. 1~ 341 (1958) .
Pergamon Press Ltd .
A CYTOCHEMICAL STUDY OF AMINOPEPTIDASE ACTIVITY IN THE RABBIT EPIDIDYMIS Birgitta Hellatröm and Lennart Nicander Department of Anatomy and Histology, Royal Veterinary College Stockholm 50, Sweden
(Received 22 May 1967)
A very high aminopeptidase activity has been histochemically demonstrated (1) in the epididymal head of many different mammals including rabbits . However, no information was given of the distribution of this activi ty between the efferent ductulea and the epididymal duct, or regarding the cytological localization of the activity . To receive information of these topics, aminopeptidase activity was studied in pieces from different parts of the rabbit epididymas, in fresh tissue and after fixation for one hour in 4% glutaraldehyde in phosphate buffer, pH 7 . 4 at 4 ° C . Sections were cut in a cryostate at 5 to 10 microns and enzyme activity was studied with L-alanyl4-methoxy-2-naphtylamide as a substrate (6) . The incubation time varied from 10 to 3~ minutes . Control material from the kidney cortex and the mucosa of the small intestine was studied simultaneously, as the luminar surfaces of ` ' these strongly absorbing epithelia are well known to show a very high aminopeptidase activity . Activity was never observed in any region of the epididymal duct . A marked activity was observed along the luminar surface of the non-ciliated cells of the efferent ductulea, very probably in their'microvillous border (Fig . 1) . The ciliated cells appeared to be negative . The control sections
1749
1750
AMINOPEPTIDASE ACTIVITY
FIG .
Vol . 6, No . 16
1
Portion of an efferent ductule of the rabbit fixed in glutaraldehyde . Aminopeptidase activity can be seen in the microvillous border of the nonciliated cells whereas the ciliated cells (arrows) appear to be negative . showed a very high activity in the brush border of the proximal kidney tubules and the striated border of the surface epithelium of the small intestine . Thorsteinseon (7), who found some di- and tripeptidase activity in the homogenized rabbit epididymis, mentioned the possibility that some activity was present in the epididymal plasma but ascribed most of the activity to the sperm cells . The present demonstration of aminopeptidase activity in the micro~illous border of the non-ciliated cells of the efferent ductules is in accordance with the relationship of these cells to the proximal tubule cells of the embryonic mesonephros and with the modern view, recently given support by physiological (2) and ultra structural (3, 4, 5) studies, that the efferent ductules have a marked resorptive function .
References 1.
L . ARVY, C . R . Acad . Sci .
254, 4202 (1962) .
2.
B . CRABO and B . GUSTAFSSON,
3
A . -F . HOLSTEIN, Z . Zeltforsch . 64, 767 (1964) .
J . Repr . Fert . ~ 337 (1964) .
Vol . 6, No . 16 4.
A. J
AMINOPEPTIDASE ACTIVITY
1751
LADMAN and W . C . Young, J. Biophys . Biochem. Cytol. 4, 219
(i958) . 5.
J. MARTAN, Z . HRUBAN and A. SLESERS, J. Morph. 121, 81 (1967) .
6.
B . MONIS, H. WASSERKRUG and A. M. SELIGMAN, J. Hietochem.
7.
Cytochem . ~ 503 (1965) .
T, THORSTEINSSON, Am . J Physiol. 1~ 341 (1958) .