生技英文論文報告
Tissue and Cell
Serous goblet cells: The protein secreting cells in the oral
cavity of a catfish, Rita rita (Hamilton, 1822) (Bagridae,
Siluriformes)
指導老師：褚俊傑
組員：4A1H0002 林侑靜
4A1H0006 謝宜玲
4A1H0037 林芷彤
出處：Tissue and Cell
46 (2014) 9– 14
標題：
Serous goblet cells:
The protein secreting cells in the oral cavity of a
catfish, Rita rita
(Hamilton, 1822) (Bagridae, Siluriformes)
作者：
Madhu Yashpal , Ajay Kumar Mittal
Journal: Tissue And Cell
Impact Factor:1.095
Introduction
 Mucus, in the oral cavity of fish, is predominantly secreted
by the mucous goblet cells.
 Mucous goblet cells involved in diverse roles :
1.trapping of food particles
2.formation of food bolus
3.solubilization of food materials
4.Facilitation of mastication
5.initial digestion of starches and lipids
6.lubrication and protection of epithelial surfaces
7.cleansing the oral cavity
8.antimicrobial activity
Introduction
 In teleost , the secretions elaborated by the cells, which
are mainly characterized by the presence of distinct
eosinophilic granules occupying large parts of the
cytoplasm also contribute to the surface mucus.
 These ‘granular’ cells, involved in proteinaceous rather
than mucoid secretions, were first described and
designated as “serous goblet cells” by Whitear .
Materials and methods
1. Fish samples
2. Histology and histochemistry
3. Examination and assessment of stained
sections
4. Measurements
Fish samples
 Samples Live specimens of R. rita (mean ± S.D., standard
length, Ls,105 ± 6 mm; n = 10), irrespective of their sex
were collected from river Ganges, Varanasi, Uttar
Pradesh, India.
 Maintained in a laboratory aquarium with a layer of sand
at the bottom for 24–48 h at 25 ± 2◦C.
 The fish were regularly fed with minced goat liver and
sacrificed by exposure to ice cold water for an extended
period of time (∼5 min) following Mittal and Whitear .
 After the sacrifice, pieces of the roof and floor of
the oral cavity were excised, rinsed in
physiological saline and fixed in aqueous
1. Bouin’s fluid (18–22h)
2. Zenker’s fluid (24 h)
3. Helly’s fluid (24 h)
for histological studies and in
10%Neutral Formalin (24 h) for protein
histochemistry.
Histology and histochemistry
 Intact sheets of the epithelium covering the roof and the floor of the
oral cavity were separated by dissecting the fixed pieces of tissue
under a Nikon stereoscopic SMZ-1B microscope (Nikon, Nippon
Kogaku K.K., Tokyo, Japan) to remove the bones.
 The tissues were dehydrated through an ascending series of ethanol
concentrations, cleared in cedar wood oil and embedded in paraffin
wax (58–60◦C; Merck Specialties Private Limited, Mumbai, India).
 Sections were cut at a thickness of 6μm using a Leica semimotorized rotary microtome.
 The sections were mounted on ethanol-cleaned glass slides
with-out any adhesive and were dried in an oven at 40◦C.
 Sections were deparaffinized in xylene and were hydrated
through a descending ethanol series.
 For histological studies, the paraffin sections of aqueous
Bouin’sfluid, Zenker’s fluid and Helly’s fluid fixed tissues were
stained with
1. Ehrlich’s hematoxylin and eosin (H/E)
2. Papinicolaou’s stain
3. Verhoeff’s elastin stain
4. Mallory’s triple stain
5. Altmann’s Acid Fuchsin
6. Regaud’s iron hematoxylin
7. Heidenhain’s iron hematoxylin
 Sections of the 10% Neutral Formalin fixed tissues were
subjected to a series of histochemical methods (Table 1)
Examination and assessment of stained
sections
 Tissues were examined using a Leitz ‘Laborlux S’
microscope equipped with a digital camera system for
automatic microphotography and to record the results on a
Vintron Pentium IV computer.
 The histochemical methods used in this study were
performed on tissue sections from several samples of the
fish species and the results obtained from each method
were consistently reproducible.
 Evaluation of staining intensities was based on subjective
estimates by all authors after examination of several
tissue sections.
Measurements
 Samples of 10 randomly selected sites in cross sections of
each tissue were analyzed for the estimation.
 Data thus obtained from ten specimens (n = 10 fish)
irrespective of their sex were pooled and the results were
expressed as mean ± S.D.
 Statistical analyses of data were conducted using SPSS
(ver.16.0) software.
 All the data was subjected to one way analysis of variance
(ANOVA) supplemented with Student–Neuman–Keuls (SNK)
post hoc test.
Results
 In R. rita, in addition to the mucous goblet cells and the
club cells, the SGCs constitute the secretory components
of the oral epithelium (Fig. 1a), which show striking
differences in their density and dimensions (p < 0.05;
Tables 2 and 3).
 However, no significant differences in the area of the
secretory cells were observed in the floor of the oral cavity.
 The dorsal side of the velum showed statistical
significance when the perimeter, diameter and
major axis were analyzed, while other regions such
as ventral side of the velum and tongue showed no
significant difference compared to the lower jaw of
the floor of the oral cavity (Table 3).
表２
表３
(a) General structure of the oral epithelium constituted of the mucous goblet cells (arrows), the SGCs
(barred arrows), the club cells (asterisks), the lymphocytes and the eosinophilic granular cells
(arrowheads).
(b) Same as (a) in higher magnification showing SGCs (barred arrows) and mucous goblet cells (arrows) in
the epithelium.
(c) Mallory’s triple stain method, showing SGCs (stained deep red) and mucous goblet cells (stained light
blue) in the outer layer of the epithelium covering upper jaw.
(d) Papanicolaou’s stain method, displaying SGCs (stained deep orange red) and blue the mucous goblet
cells (stained blue) in the outer layer of the oral epithelium.
(e) Altman’s acid fucshin stain method, showing SGCs (stained red) and the mucous goblet cells (stained
pink) in the outer layer of the oral epithelium.
(f) Verhoeff’s elastin staining method, showing SGCs (stained black) and the mucous goblet cells (arrows)
in the epithelium.
(g) Regaud’s iron hematoxylin staining method, showing SGCs (stained black) and the mucous goblet cells
(stained brown).
(h) Heidenhain’s iron hematoxylin staining method, showing SGCs (stained black) and the mucous goblet cells
(arrows).
(i) Mercury-bromophenol blue method, demonstrating the protein nature of the SGCs stained deep blue
with purple tinge. Reaction is feeble in the mucous goblet cells.
(j) Acid solochrome Cyanine-R method, displaying positive reactions for basic proteins in the SGCs.
(k) Same as (j) in higher magnification showing SGCs stained deep orange-red (acid solochrome
cyanine-R).
(l) DMAB-nitrite method, indicating the presence of tryptophan and 3-indole derivatives in deep blue
stained SGCs.
(m) Performic acid Schiff’s Reaction method, showing the presence of cystine bound disulphide (—SS)
groupsin pink stained SGCs.
Histochemistry
 Strong blue with purple tinge reaction with the mercurybromophenol blue (method 1; Fig. 1i) for general proteins
and vivid orange red reaction with the acid solochrome
cyanine-R for basic proteins (method 2; Fig. 1j and k) →
the granular content of SGCs are highly proteinaceous in
nature.
 The granules stain intense blue with the DMAB-nitrite
(method 3), which is abolished with prior iodination
(method 4) → the presence of tryptophan and 3-indole
derivativesin high concentrations (Fig. 1l).
 Strong orange reaction with Mil-lon (method 5) that is abolished by
prior iodination (method 6) → the presence of high amounts of
tyrosine in these cells.
 Moderate pink reaction with ninhydrin-schiff (method 7) that is
abolished by prior deamination (method 8) → the presence of lysine
(— NH2 ) groups in moderate concentrations.
 A strong purplish red reaction with DDD (method 9), which is not
obliterated with prior N-ethyl maleimide block or iodine oxidation
(methods 10 and 11) → the reaction is non-specific and is not due to
the presence of cysteine bound sulphydryl(—SH) groups.
 Positive reactions with performic acid-alcian blue
(method 12) and performic acid-Schiff (method 14;Fig.
1m), which are abolished with prior thioglycollate
reduction (method 13 and 15) → these cells contain
cystine bound disulphide (—SS) groups.
 The SGCs remain unstained with Sakaguchi reaction
(method 16) → the absence of arginine.
Discussion
 The SGCs, with strong eosinophilic granular contents,
are primarily involved in the elaboration of proteinaceous
secretions, form one of important constituents of the
secretory elements in the epithelium at different regions
of the oral cavity of R. rita.
 Further, Petrie-Hanson and Peterman (2005) pointed out
that these cells could be found in high numbers in fish
gill and gut tissues.
 The high proteinaceous content secreted by SGCs at the
surface of the oral epithelium of R. rita may have
defensive roles and acts synergistically with mucus
glycoproteins to inhibit the adherence and proliferation of
microorganisms.
 In R. rita, the tryptophan-rich secretions of SGCs may
assist in different physiological stages of digestion.

The present study also revealed that the proteinaceous
secretions of SGCs are rich in various amino acids like
tyrosine, lysine, cystine and may indicate the presence
of enzymatic pre-cursors such as pepsinogen or digestive
enzymes.

In addition to their role as substrates for protein synthesis,
these amino acids may also play a vital role in
neurotransmission, osmoregulation, stress response and
antioxidative defense .
 Since R. rita preferably dwells in muddy and dirty water it is
conceivable that the proteinaceous secretion of SGCs
provides a protective barrier to the epithelium against various
pathogens and infections, abrasions during manipulation of
food items in the oral cavity.
 It is worth mentioning that the amphibians are evolved from
freshwater fish and during the course of evolution, the SGCs
in fishes may be considered as a significant representative of
an ancient specialized line in the alimentary canal.
Conclusion
 We conclude that the SGCs, in the oral cavity of R. rita,
may possibly be involved in the secretion of a broad
spectrum of proteins, similar to those found in mammalian
saliva.
 The secretions of SGCs in harmony with those of mucous
goblet cells orchestrate various functions of mucus such as
handling, maneuvering and driving of food items toward
the esophagus, maintaining taste sensitivity and protection
of the oral epithelium.
 In addition, the SGCs may also be considered as the
primary defensive cell of the oral epithelium of R. rita.
 The results of the present study could function as the
initial step to elucidate the precise roles of secretions of
SGCs in the oral cavity of fish.
 Further, such exploration of proteome of SGCs not only
add knowledge to the oral physiology in fish.
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