IJune 1995

Asiatic Herpctological ResearchVol.

6, pp.

111-113

A Study on the Comparative Cytology of Some Endocrine Glands inRana plancyi between Hibernation and Post-hibernation
JlQlNG
Department of Biology, Xuzhou Teachers College, Xuzhou, Jiangsu, 221009 China
Abstract:-This paper studies the ultrastructure of the pituitary gland cell and the adrenal cortex cell in Ranabetweenhibernation and post-hibernation. The results show that the two kinds of cells mentioned above
plancyi
are much less inactive during hibernation than during post-hibernation.

The significance of those results is also

discussed.

Key words: Amphibia, Anura, Rana plancyi, pituitary gland, adrenal cortex, comparative cytology.

Introduction

standard method, and the specimens were
examined with a Hitachi 600-A-II electron

Hibernation is an adaptive strategy offrogs for keeping out of the cold during thewinter. Studying the hibernation biology offrogs is beneficial to protecting the frogs andmicroscope.

Results

making use of frog resource. No paper
related to the comparative cytology of theendocrine glands in frogs has been reported
in China for many years. This paper reports
the results of studying the comparativecytology of the pituitary gland cell and theadrenal cortex cell in Rana plancyi between
hibernation and post-hibernation by using atransmission electron microscope.

Methods

Pituitary gland cell

The pituitary gland cell of the hibernationgroup has plenty of glycogen particulates (PI.
1:1) but few rough endoplasmic reticulum andmitochondrium (PI. 1:2), while the pituitary
gland cell of the post-hibernation group has
plenty of rough endoplasmic reticulum andGolgi bodies but no glycogen particulates(PI. 1:3). The pituitary gland cell of the posthibernation group also has plenty of secretory(PI. 1:4), and some secretory
granules can sometimes be seen moving toblood capillary (PI. 1:5).

granulesAccordingto

theregular pattern ofhibernation in the locality, many specimensof Rana plancyi were collected from a little
river in

October 1992,

inAdrenal cortex cellthe suburbs of

Xuzhou City, put into a box, and then laidoutdoors

duringthewinter.

Somespecimens, which represent the hibernationgroup, were fetched from the box and usedfor the experiment on January 8, 1993.

Some specimens

representing the posthibernation group were collected from thesame little river mentioned above and wereused to do the experiment on May 17, 1993.
Four specimens were collected from thetwo groups, regardless of their sex. The
specimens were killed and dissected so that

According to the result of the examinationof the semi-thin sections, the adrenal cortex
in the adrenal gland was defined.
The
adrenal cortex cell has tubular cristate
mitochondrium as its marking. The adrenal
cortex cell has plenty of lipid drops, somesmooth endoplasmic reticulum and few

mitochondrium

1:6,(PI.
7)
duringhibernation, but has plenty of mitochondrium(PI. 1:8), few lipid drops and plenty of
expanded smooth endoplasmic reticulum (PI.
1:9).

the pituitary gland and the adrenal gland wereobtained.

The two glands were fixed with

Discussion

4% glutraldehyde and embedded in Epon812. Ultra-thin sections were doubly stained

The pituitary gland is the most importantwith uranyl acetate and lead citrate by theendocrine gland in the frog and plays an© 1995 by Asiatic Herpetological Research|Vol. 6, p. 112

Asiatic Herpetological Research

June 1995

Plate I
1.

Pituitary gland cell showing glycogen particulates during hibernation (arrows).

X 12 000

2. Pituitary gland cell showing mitochondrium(Mt), rough endoplasmic reticulum (RER), Golgi bodies (GB)and secretory granules (SG) during hibernation. X 15 000

3. Pituitary gland cell showing Mt,RER and GB during post-hibernation. X 20 000

SG during post-hibernation. X 17 000
5. Pituitary gland cell showing SG near the blood capillary (BC) during post-hibernation. X 20

4. Pituitary gland cell showing

6. Adrenal cortex cell showing lipid drops (LD) and000

Mt during hibernation. X 20 000

7. Adrenal cortex cell showing smooth endoplasmic reticulum (SER) during hibernation.

X 20 000

Mt during post-hibernation. X 20 000
9. Adrenal cortex cell showing expanded SER and LD during post-hibernation. X 20 000
8. Adrenal cortex cell showing

O

Mt

GB-?6

SGMt"

GB»*

RER.--£*£$& •-..._•>•.

fe••

N

•^SGp.

IJune 1995

Vol. 6, p. 113

Asiatic Herpetological Research

important role in its hibernation. It cansecrete, releasing hormone which canregulate the activity of the other endocrine
glands. The studies on frog cytology havenot concerned the pituitary gland for manyyears. Previous work (Daguy, 1963; SaintGirons, 1975) has showed that the pituitary
gland in some reptiles increase in activity
several weeks before the end of hibernation.
This investigation shows that the pituitary
gland cell is inactive during hibernation, but
It alsoduring post-hibernation.
theofthatthebehavior
pituitarysuggested
gland in frogs is similar to the same gland in
reptiles during hibernation and post-activehibernation.

Theadrenal cortex can secrete
glucocorticoid and mineralocorticoid. The
two kinds of hormones can regulate
glucometabolism and mineralometabolism.
These two kinds of hormones are bothsynthesized in the smooth endoplasmic
reticulum, so that the number of smooth
endoplasmic reticulum can indicate thesecreting level of the two kinds of hormones.
Previous work (Robertson et al., 1959; Chanet al., 1971) have shown that the adrenal
cortex is inactive during the winter and active
This investigation also
in the summer.
shows that the adrenal cortex cell is active
during post-hibernation and inactive duringhibernation. According to this investigation,
considered that the activity of the adrenal

it ismay begin from the end of hibernation.

Acknowledgments
The author is deeply indebted toProfessor Shou-chang Zou for having
supplied the materials and for his helpfuladvice throughout the research. The author
also wishes to thank Professor She-chaoChen for his excellent technical assistance.
Literature Cited

CHAN, S. W. C. AND J. G. PHILIPS.
Seasonal

variations

inproduction

in

1971.

vitroofcorticosteroids by frog (Rana rugulosa) adrenal.
Journal of Endocrinology 5:1-17.

DAGUY, R.

1963. Biologie de la latence hibernalechez Vipera aspis. Vie Milieu 1963 14:311-443.

ROBERTSON, O. H. AND B. C. WEXLER.

1959.

organs and tissues ofHistological changes
migration and spawning Pacific salmon (Genusin theOncorhynchus). Endocrinology 66:222-239.

SAINT GIRONS, H.

1975. Le cycle annuel desglandes endocrines chez les serpents des regions
temperas. Bulletin Zoology of France 100:654-655.