Due to the enhanced antibiotic resistance observed
in various farm animal species, administration of
antibiotics to control and/or manage microbial diseases
may impose certain hazards (
Ciprofloxacin (CPFX) is a second-generation
fluoroquinolone broad-spectrum antibiotic used to treat a number of gram-positive and -negative bacteria
that cause infections of the bones and joints, and
respiratory and urinary tracts. It mainly acts through
inhibition of a type II topoisomerase, DNA gyrase,
which is necessary to unwind replicated prokaryotic
DNA. CPFX is routinely administered by urologists
and fertility specialists in order to control male
reproductive infections. Its side effects occur most
frequently in the gastrointestinal tract and central
nervous system. Allergic and cardiovascular reactions
are additional adverse effects observed during
treatment with CPFX (
Leydig and Sertoli cells play key roles in spermatogenesis
and cell lineage metabolism. These cells
are considered to be important cells for intratesticular
endocrine function (
In this experimental study, we used 24 mature 8-week-old male NMRI mice that weighed 28.00 ± 3 g. The animals were purchased from the Animal Resources Center of the Faculty of Veterinary Medicine, Urmia University, Iran and were acclimatized in an environmentally controlled room (22+2°C, 30- 60% relative humidity, 12/12 hours dark-light cycle). Food and water were given ad libitum. In this study all experiments conducted on the animals were in accordance with the Urmia University guidance of the Ethical Committee for Research on Laboratory Animals. Following a one week acclimation period, we divided the animals into three groups (n=8), control- sham and two test groups. The test subgroups received either a high or low dose of CPFX.
CPFX(Fluka17850, USA) was suspended in 0.5%
carboxymethylcellulose (CMC) and administered
by gavage once daily for 45 consecutive days. Mice
in the test groups received either 206 mg/kg(low
dose) or 412 mg/kg(high dose) CPFX. The 206 mg/
kg dose for mice is comparable to the human daily
therapeutic dose, following correction for interspecies
differences with a dose-scaling factor (
After 45 days the animals were euthanized by a special CO2 device and one-half of the testes specimens were dissected out and fixed in 10% formalin fixative for histological investigations and subsequently embedded in paraffin. Sections (5-6 µm) were stained with periodic acid Schiff (PAS) staining for intracytoplasmic carbohydrates. We evaluated the numbers of Leydig cells per mm2 of interstitial connective tissue and Sertoli cells per ST. The slides were analyzed under light microscope at × 400 and ×1000 magnifications.
In order to perform histochemical analyses, the frozen section was used for freshly dissected samples. The Sudan-Black B (SB) staining was performed to evaluate the rate of lipid foci supplement in GE for test and control-sham animals and to identify the Leydig cells cytoplasmic biosteroid supplement. ALP staining was conducted to demonstrate the ratio of this enzyme. We used lipase staining to detect the lipase enzyme ratio in GE. All specimens were evaluated at ×400 and ×1000 magnifications.
Blood samples from corresponding animals were collected by decapitation. Following centrifugation at 3000 g for 5 minutes, sampleswere assessedfor serum levels of LH, FSH and testosterone. We used the enzyme-linked immunosorbent method to evaluate plasma levels of FSH, LH and testosterone.
We analyzed the study data with SPSS software version 16 (SPSS, Inc., IL, USA). All results are presented as mean ± SD. Differences between quantitative histological and hematological data were analyzed with one-way ANOVA, followed by the Tukey test.We considered p<0.05 as significant. Correlation between lipid-positive Sertoli cells with dissociated GE in STs and the correlation between the number of Leydig cells/mm2 of the connective tissue with the number of Sertoli cells/ST were analyzed on an Indigo-2 O2 work station (Silicon Graphics, Mountain View, CA) using Matlab (Math Works, Inc., Natick, MA).
Light microscopic analyses showed that the spermatogonia
and spermatocyte cells from low and high dose
CPFX animals had low cytoplasmic carbohydrate ratios
compared to control-sham animals (
Cross-section from testes. A. Control group. Note the germinal epithelium (GE) integrity and normal PAS reaction. .B. Low dose group with light germinal cell dissociation and moderated PAS reaction present in seminiferous tubules (STs). C. High dose group with germinal cell dissociation and faint PAS-stained germinal lineage associated with remarkable edema in interstitial connective tissue. Higher magnification from interstitial connective tissue, note faint PAS-stained Leydig cells in D. and dense PAS-stained cells in E. (arrows). PAS staining, contrasted with Hematoxilineherrise, (A and B: ×400; C: ×600). Scale bars are 1.9 µm.
In CPFX mice the majority of Leydig cells exhibited
a dense PAS reaction; rarely, these cells showed
faint PAS-stained cytoplasms. In CPFX-treated
mice there were decreased numbers of Leydig cells/
mm2 of connective tissue. In contrast ,in the control
animals there were significantly higher numbers of
Leydig cells which were manifested with a faint cytoplasmic
carbohydrate ratio (
Mean number of total Leydig cells (Total.L.Cells) and PAS-positive Leydig cells (PAS.P.Cells) per mm2 of interstitial connective tissue.
* and #;Significant differences (p<0.05) between test and control-sham groups. There are no remarkable differences(p>0.05) between low and high dose ciprofloxacin (CPFX) groups. All data are presented in mean ± SD.
Comparing the number of PAS-positive cells
between control-sham and test groups revealed
significantly (p<0.05) lower numbers of spermatogonia
and spermatocyte cells/ST which are exhibited
a PAS reaction in CPFX-treated animals
Histochemical observations demonstrated
that in contrast to the test groups, the first
three layers of the GE in control-sham animals
manifested with a faint reaction against SB
staining; the upper layers had lipidophilic features.
In the CPFX groups the spermatogenesis
cell lineage showed remarkably higher
numbers of cells with SB-positive cytoplasms
Test groups showed significantly (p<0.05) higher
numbers of lipid-positive spermatogonia and
spermatocyte cells per ST (
A. Average of total spermatogonia (T.SP.C) and total PAS-positive spermatogonia (T.P.P.SP.C) cells. B. Total spermatocyte (T.S.C) and total PAS-positive spermatocyte cells (T.P.S.C) per seminiferous tubule.
* and #;Significant differences (p<0.05) between test and control-sham groups. There are no significant differences (p>0.05) between low and high dose ciprofloxacin (CPFX) groups. All data are presented in mean ± SD .
Cross-section from testes. A. Control group.Note the first three layers of the germinal epithelium (GE) with a negative reaction to lipidophilic staining (arrow); the last layers have faint Sudan black-B(SB)-stained cytoplasm (arrow head). Leydig cells (blue arrow) show dense lipid-positive cytoplasm which is indicative of normal biosteroid function. B. Low dose ciprofloxacin (CPFX)group.Leydig cells (blue arrow) show dark lipid-positive cytoplasms. Faint SB-positive stained dissociated GE shown by white arrow. C. High dose CPFX group.Note the Leydig cells that have faint SB reaction in the cytoplasm (head arrow) that is associated with remarkable edema in the interstitial connective tissue. The first three layers of germinal lineage lipid-positive reaction sites (arrow). SB staining contrasted with nuclear fast red (A: ×400, B: ×600 and C: ×400). Scale bars are 1.9µm.
A. Average of total spermatogonia (T.SP.C) and total lipid-positive spermatogonia (T.L.P.SP.C) cells. B. Total spermatocyte (T.S.C) and total lipid-positive spermatocyte cells (T.L.P.S.C) per seminiferous tubule.
* and #;Significant differences (p<0.05) between test and control-sham groups. There are no remarkable differences (p>0.05) between low and high dose ciprofloxacin (CPFX) groups. All data are presented in mean ± SD.
Mean numbers of total Leydig cells (Total.L.Cells) and lipid-positive Leydig cells (lipidophilic cells) per mm2 of interstitial connective tissue.
* and #; Significant differences (p<0.05) between test and control-sham groups. There are no significant differences (p>0.05) between low and high dose ciprofloxacin (CPFX) groups. All data are presented in mean ± SD.
A. Correlation between number of Leydig cells in one mm2 of interstitial connective tissue with Sertoli cells per tubule. B. Correlation between lipid-positive Sertoli cells per tubule with germinal epithelium (GE) dissociation. There is a positive correla- .tion between the number of Leydig and Sertoli cells, Sertoli cell intra-cytoplasmic lipid accumulation and GE dissociation
In comparison to control-sham animals, CPFX-treated
animals showed remarkably lower numbers of SB-positive
Leydig cells/mm2 of interstitial tissue (
In both low and high dose CPFX-treated animals, higher numbers of Sertoli cells/ST showed lipid-positive reactions. Sertoli cells in controlsham animals showed a negative reaction against lipid staining. Correlation between the number of Leydig cells/mm2 of connective tissue with the number of Sertoli cells/ST and correlation between lipid-positive Sertoli cells with dissociated GE in STsare presented in figures 7A and B.
We observed cytoplasmic lipase in spermatogenesis
cells series in the control group. Animals in the test
groups had high lipase-stained sites in the cytoplasms
of the spermatogenesis cells series (
Light microscopic analyses showed significantly increased ALP-positive cells/STin CPFX animals. This impairment was mainly observed in disrupted GE.
Control-sham animals showed remarkably faint
reactions against ALP staining in different cell
Significantly (p<0.05) higher numbers of Leydig
cells/mm2 of the test animals testicleshad ALPpositive
Cross-section from the testes. A. Control group. Note the faint lipase reaction in the spermiogenesis cell lineage. B. Low dose ciprofloxacin (CPFX) group and C. High dose CPFX group. Note lipase-positive areas in spermatogonia and spermatocyte cells. Lipase staining (A, B and C: ×400). Scale bars are 2.3µm.
Cross-section from testes. A. Control group.Note normal seminiferous tubules (STs) with negative ALP reactivated sites in germinal epithelium (GE) and normal interstitial connective tissue (Int). B. Low dose ciprofloxacin (CPFX) group with faint edema in the interstitial connective tissue (Int) and faint ALP-stained upper layers of the GE (arrows) in seminiferous tubules (STs). C. High dosed CPFX group, not dense ALP sites in preleptotene spermatogonia cells (arrow head) and spermatocyte type one cells (arrows) associated with remarkable edema in the interstitial connective tissue (Int). ALP staining contrasted with nuclear fast red (A and B: ×600, C: ×100 and D: ×500). Scale bars are 2.9µm.
Mean average of ALP-positive Leydig cells per mm2 of interstitial connective tissue.Stars indicate significant (p<0.05) differences between marked groups with controlsham group. All data are presented as mean ± SD.
Test groups showed significantly (p<0.05) higher
numbers of ALP-positive spermatogonia and
spermatocyte cells per ST (
Hematological analyses revealed that the testosterone
level decreased in CPFX-treated mice,
which was statistically significant (p<0.05) between
different groups. The serum levels of FSH
and LH in high dose-treated animals decreased
Effects of ciprofloxacin (CPFX) on serum levels of testosterone, FSH and LH
|Groups||Testosterone(ng/ml)||FSH (Iu/L)||LH (Iu/L)|
|5.42 ± 0.23a||0.69 ± 0.09a||0.76 ± 0.11a|
|4.58 ± 0.18b||0.77 ± 0.15a||0.76 ± 0.10a|
|4.2 ± 0.10c||0.53 ± 0.09b||0.60 ± 0.11b|
Data are presented as mean ±SD. Different letters in each column indicate that data are significantly different (p<0.05).
A. Average of total spermatogonia (T.SP.C) and total ALP-positive spermatogonia (T.P.P.SP.C) cells. B. Total spermatocyte (T.S.C) and total ALP-positive spermatocyte cells (T.P.S.C) per one seminiferous tubule.
* and #; Significant differences (p<0.05) between test and control-sham groups. There are no significant differences (p>0.05) between low and high dose ciprofloxacin (CPFX) groups. All data are presented in mean ±SD.
Although the therapeutic and prophylactic effects
of CPFX on different gram-positive and -negative
bacteria has been well documented, various studies
reported that even short term administration
of CPFX promoted male reproductive toxicity (
Our findings showed that long term administration of CPFX resulted in remarkable alterations in intracellular biochemical supplements. The intracytoplasmic carbohydrate ratio decreased in spermatogenesis cell lineage and simultaneously the lipid foci supplement and lipase enzyme increased in the cytoplasm of these cells. An increase in ALP level was mainly manifested in degenerated GE. Significant changes also occurred in serum levels of testosterone, LH and FSH.
Previous studies have shown that glucose transporters
are the main ways to transfer glucose to the
STs; carbohydrates are the major sources of energy
for hyper-mitotic cells (
In the present study, both spermatogonia cells
and spermatocytes had PAS-negative reactions in
CPFX-treated animals. Thus, following CPFX administration,
there was decreased glucose transport
and/or metabolism in spermatocytogenesis and the
spermatogenesis cell lineage which resulted in a
switch in their energy source from glucose to lipids.
As a result, cytoplasmic lipid foci increased
in the cytoplasms of these cells, particularly in the
first three layers. Simultaneously, due to insufficient
energy, these cells were unable to synthesize
essential proteins and therefore they underwent
apoptosis and disruption (
The increase of lipase enzyme synthesis in
CPFX-treated groups revealed that the metabolic
pathway of the cell lineage in the first three layers
of the GE was altered by using the lipid sources
from different biological activities. The number
of Sertoli cells with SB-positive cytoplasm increased
in CPFX-treated groups which showed the
effects of CPFX in lipid accumulation in Sertoli
cells. Lipid supplement in Sertoli cells varies with
different conditions. Forinstance during phagocytosis
of residual bodies or damaged cells, the
intracytoplasmic ratio of lipids increases in their
According to previous reports, constant levels
of FSH and LH are essential for initiating and
supporting the spermatogenesis process (
Following CPFX administration the spermatogonia, spermatocyte and Sertoli cells in STs switch their energy source from glucose to lipids. Thus, inadequate energy supplement leads to cellular degeneration. Impairment of Leydig cells in testosterone synthesis negatively impacts this pathological process by affecting Sertoli cells.