Cytologic study of normal canine testis

Evaluation of Stallion Testicular Cell Types by Flow Cytometry

Flow cytometry procedures can be used for evaluation of both spermatogenic efficiency and diagnose disorders of stallion spermatogenesis. Aims of this study were to compare two testicular sample acquisition techniques (needle aspirate-N and tissue wedge-T) and results when using flow cytometry and histology procedures. Testicular cell types were stained with acridine orange, and nine regions (R2 to R10) were identified and enumerated following acquisition by either N or T. Testes were also grouped and analyzed by size and sexual maturity (Small [immature] compared with Large [mature]) and used to determine if flow cytometry procedures could be used to detect differences. For both N and T, percentages of 2n cell types were greater in the Small than Large testes, whereas percentages of 1n cell types in N were greater in the Large than Small testes (P < .05). Testicular cell types in N regions were correlated to similar T regions (r between 0.51 and 0.99; P < .05) in both groups. Flow cytometry and histology scores were correlated in both groups (r between -0.95 and 0.93, P < .05). There were small differences in number of testicular cell types from N and T. With both sample acquisition methods, there was discrimination between the Small and Large testes, therefore, evaluation of testicular cell types using flow cytometry procedures might have clinical applications. Results with comparison of flow cytometry to histology procedures indicate that flow cytometry can be applied clinically to identify changes in testicular cell types of stallions using a needle aspirate.

Cytological description of testicular cell populations in sexually mature cats with normal spermatogenesis

In cats, assessment of the testicular function is mainly based on sperm evaluation. Whatever the technique used, the volume of collected sperm is often small, which may lead to technical difficulties to achieve the semen evaluation in routine practice. Fine-needle aspiration (FNA) biopsy of the testicular parenchyma is one of the other methods used to assess testicular function. The aim of this study was to explore the relevance of FNA in the assessment of testicular cells in sexually mature cats. Eighteen cats over one year of age were recruited among animals presented for surgical neutering. Semen was collected by electroejaculation before it was evaluated. FNA biopsies of the testicles were taken using a 21-gauge needle. After castration, histological analysis of the testes was performed. Semen evaluation and histological analysis showed no anomalies, which confirmed normal spermatogenesis in all the cats and allowed a proper interpretation of the cytological findings. The cells identified through cytological examination were spermatogonia (1.99 ± 0.17%), primary spermatocytes (10.49 ± 0.74%), round spermatids (34.80 ± 1.57%), elongated spermatids (23.59 ± 2.02%), spermatozoa (21.56 ± 1.86%), Sertoli cells (7.53 ± 1.23%) and Leydig cells (0.04 ± 0.03%). However, spermatocytes II were not identified. This is due to the low proportions of these cells, related to their very short lifespan. Likewise, the very low number of Leydig cells observed is probably due to the damage caused during the aspiration stage. This study showed that fine-needle aspiration is an efficient method to describe cytologically normal testicular populations, a cornerstone for future research aimed to study abnormal spermatogenesis and to correlate it to cytological proportion of germ cells.

Age-related changes in interstitial fibrosis and germ cell degeneration of the canine testis

Fifty-five healthy medium-sized dogs were divided into four groups; young (1-3 years old, n = 14), adult (>3 to 6 years old, n = 12), old (>6 to 9 years old, n = 14) and senile (>9 years old, n = 15). After routine orchiectomy, testes were collected, and the degree of white streak areas on cut surfaces was subjectively assessed. Later, testicular tissue sections were stained with haematoxylin and eosin and Masson's trichrome for evaluation of germ cell degeneration and the proportion of interstitial connective tissue, respectively. Semiquantitative severity scoring of germ cell degeneration and quantitative analysis of spermatogenic cells for spermatic index (SI) and Sertoli cell index (SEI) was performed. The score of white streak on cut surface area of the testes increased with age, being higher (p < 0.05) in senile dogs than other age groups; no difference was found between adult and old dogs. The proportion of testicular interstitial fibrosis was highest (p < 0.05) in senile dogs. Positive correlations between age and white streak area (rho = 0.77, p < 0.01) as well as age and interstitial fibrosis (rho = 0.63, p < 0.01) were observed. The severity of germ cell degeneration gradually increased with age and differed among age groups (p < 0.05). Age positively correlated with atrophy of seminiferous tubules (rho = 0.93, p < 0.01). The SI was lower (p < 0.05) in senile dogs compared to other age groups, and SI was not different among young, adult and old dogs. Conversely, SEI was significantly higher in senile dogs compared to young, adult and old dogs. A negative correlation between age and SI (rho = -0.69) and a positive correlation between age and SEI (rho = 0.68) were significant (p < 0.01). In conclusion, influence of age on testicular interstitial fibrosis and germ cell degeneration/depletion were pronounced in dogs over 9 years old.

Influence of season and climatic variables on testicular cytology, semen quality and melatonin concentrations in crossbred bucks reared under subtropical climate

Seasonality in reproduction and effects of climatic variables on testicular cytology and semen quality in bucks reared under subtropical climatic conditions were not well understood. In the present study, using testicular cytology, semen evaluation and melatonin concentrations assessed over a period of 1 year, we report that bucks reared under subtropical climatic conditions did not show seasonality in reproduction. Climatic variables including temperature, relative humidity, temperature-humidity index (THI), sunshine hours and day length were recorded daily during the whole period of experimentation (one complete year). Ejaculates were collected from crossbred (Alpine X Beetal) males (n = 6) biweekly using artificial vagina, and semen quality (volume, mass activity, sperm concentration, motility, viability, membrane integrity and protamine deficiency) was assessed. To understand the seasonal influence at testicular level, using fine needle aspiration biopsy method, testicular cells were aspirated and different types of cells and testicular cytology indices were quantified. Blood was collected biweekly for estimation of melatonin concentrations. Mass activity was higher (P < 0.05) during rainy season while individual sperm motility and sperm concentration were higher (P < 0.05) during rainy and autumn seasons as compared to other seasons. Sperm functional parameters did not show any differences during different seasons. Sertoli cell count, spermatogenic cell count and testicular indices did not differ among the seasons. Melatonin concentrations also did not differ significantly among the four seasons studied. Among the climatic parameters, THI had significant (P < 0.05) influence on sperm quality. The proportion of Sertoli cell in the testicular cytology had a significant and positive relationship with RH, THI and day length. It was concluded that seasonal variations are less evident in terms of spermatogenesis and semen quality in Alpine X Beetal crossbred bucks reared under subtropical climatic conditions.

Testicular cytology by fine needle aspiration in domestic cats

In cases where semen collection in tom-cats is not possible, FNA of testes is the alternative to evaluate sperm production. Although this technique for the diagnosis of fertility problems has been well discussed in other mammals (men, dogs, stallions), data for domestic cats are limited. Therefore, the aim of this study was to verify the reliability of FNA using needles of small diameters (22G and 29G) in testes of domestic cats of different ages to assess the spermatogenesis status and to present description of germ cells and Sertoli cells for cytological examinations. Thirty-four mixed breed cats aged between four months and two years presented for neutering to a Veterinary Hospital were used in this study. Under general anesthesia, testicular measures and FNA were followed by orchiectomy and imprints of the parenchyma of testes and epididymides. Cats were assigned into 3 groups: (G1) 10 cats aged less than 6 months, (G2) 14 cats aged between 6 months and one year and (G3) 10 cats aged more than one year. Cats weighted between 1.5 and 6.0 kg. The mean testicular volume (TV cm³) was 0.55 (G1), 1.18 (G2) and 2.66 (G3). Hemorrhages in the needle path were observed in more than 70% of testes. Few samples (4/68) were excluded due to blood contamination. All germ cells and Sertoli cells were identified and quantified in imprint and FNA smears. Incomplete spermatogenesis was observed in cats aged less than 6 months using both techniques (FNA and imprint); therefore, testicular FNA should not be recommended for cats at this age. Complete spermatogenesis was found in 64% of cats aged from 6 months up to one year and in all cats aged more than one year. There were no differences of Sertoli cell Index (SEI) and Spermatic Index (SI) between FNA and imprints of cats older than 6 months. In conclusion, FNA using needles of small diameter in the testes of domestic cats is viable, reliable and can be used as a tool for the analysis of the spermatogenesis status of cats older than 6 months, mainly in cases in which semen collection is not possible.

Morphometric evaluation of seminiferous tubule and proportionate numerical analysis of Sertoli and spermatogenic cells indicate differences between crossbred and purebred bulls

Aim:

The present study compared the testicular cytology and histology between crossbred (Holstein–Friesian [HF] × Tharparkar) and purebred (HF and Tharparkar) bulls to find out differences if any.

Materials and Methods:

Four peripubertal bulls from each breed were utilized for the study. Through percutaneous needle aspiration biopsy, Sertoli and spermatogenic cells were extracted, and morphometry was studied. For histological studies, testicular tissues obtained through unilateral castration were utilized. Sertoli cells specific GATA4 antibody was used to study the population of Sertoli cells in the seminiferous tubule through immunofluorescence.

Results:

The testicular weight, volume, and scrotal circumference differed significantly among the breeds. The diameter and area of the seminiferous tubule was high in HF, followed by Karan Fries (KF), and Tharparkar bulls. However, the degree of compactness, based on qualitative evaluation, was high in Tharparkar followed by KF and HF bulls. The intensity of Leydig cells was higher in Tharparkar bulls followed by KF and HF. The proportion of Sertoli cells was higher (p<0.05) in HF and Tharparkar bulls compared to KF bulls.

Conclusion:

It may be concluded that variations exist in testicular components of the breeds studied and the proportion of Sertoli cells in relation to spermatogenic cells was significantly lower in crossbred bulls compared to purebred bulls.

Variation of spermatogenic and Sertoli cell number detected by fine needle aspiration cytology (FNAC) in Iberian red deer during and out of the breeding season

The aim of the present study was to evaluate spermatogenesis in Iberian red deer, a short-day seasonal breeder, using the fine needle aspiration cytology (FNAC) technique. Reports on spermatogenesis in deer are limited and here, for the first time, FNAC has been used to evaluate changes in such physiological process during and out of the breeding season. Testes were collected from 51 stags from November 2010 to February 2011. The Sertoli index and spermatic index were significantly higher during the breeding season than out of the breeding season (P = 0.0477 and P = 0.0125, respectively). A similar pattern was described by histological analysis, in which both Sertoli cell number per tubular cross-section and Johnsen score decreased significantly from the breeding season to the non-breeding season (P = 0.0131 and P = 0.0010, respectively). Data provided by FNAC were correlated with histology: the Sertoli index was positively correlated with Sertoli cell number per tubular cross-section (P = 0.0015), whereas the spermatic index was correlated with the Johnsen score (P = 0.0497). The results of the present study indicate that FNAC is a reliable technique to evaluate spermatogenesis in Iberian red deer and suggest that Sertoli cell number is not stable in these species, reaching highest values during the breeding season.

Testicular cell indices and peripheral blood testosterone concentrations in relation to age and semen quality in crossbred (holstein friesian×tharparkar) bulls

Present study analyzed the changes in peripheral blood testosterone concentrations and testicular cytogram in relation to age and semen quality in crossbred males. Three different age groups of crossbred males viz. bull calves (6 months, n = 5), young bulls (15 months, n = 5) and adult bulls (4 to 6 years, n = 8) were utilized for the study. Testicular fine needle aspiration cytology technique was used to quantify testicular cytology and their indices. Peripheral blood testosterone concentrations were measured using enzyme-linked immunosorbent assay method. Semen samples collected from adult bulls were microscopically evaluated for quality parameters. Mean peripheral blood testosterone concentrations in bull calves, young bulls and adult bulls were 2.28±0.09 ng/mL, 1.42±0.22 ng/mL and 5.66±1.08 ng/mL respectively, and that in adult bulls were significantly different (p<0.01) from young bulls and bull calves. There was no significant difference between the proportion of different testicular cells in bull calves and young bulls. Between young and adult bulls, significant differences (p<0.01) were observed in the proportion of spermatocytes, spermatozoa, and sperm: Sertoli cell ratio. The proportions of Sertoli cells showed a significant difference (p<0.01) between the three age groups. The number of primary spermatocytes had a positive correlation with peripheral blood testosterone concentrations in bull calves (r = 0.719, p<0.01). Number of Sertoli cells per 100 germ cells was negatively correlated with blood testosterone concentration in young bulls (r = −0.713, p<0.01). Among different semen parameters in adult bulls, ejaculate volume (r = 0.790, p<0.05) had positive relationship, and sperm motility had significant negative correlation (r = −0.711, p<0.05) with testosterone concentrations. The number of Sertoli cells and Sertoli cell index had a positive correlation with various semen quality parameters (p<0.001). Results of the present study conclude that number of Sertoli cells and Sertoli cell index are good indicators of semen quality, but peripheral blood testosterone concentrations may not have a direct relationship with various seminal attributes in crossbred bulls.

Testicular cytology of alpaca: comparison between impressed and smeared slides

Testicular fine needle aspiration (TFNA) has proven to be a simple and minimally invasive procedure, which allows assessments of cytological parameters of seminiferous epithelium/tubules more accurately in a short time. Though this technique does not cause negative effects on sperm quality or any damage to testicular tissue, its use is very limited in male animal infertility diagnostics. Report on the use of this technique in South American Camelids (SAC) is very limited. Therefore, the aim of this study was to evaluate the efficacy of TFNA for identification of different testicular cells and cell indices, and their correlation with that of impression cytology. A total of 98 slides were prepared from testes of six adult alpaca males, collected immediately after slaughter. Aspiration samples were performed by inserting a fine butterfly needle (21 G) connected to a 50 ml syringe into a testicle and multiple plane aspirations were carried out to obtain the materials destined to the smear. Three different imprints on slides were taken from each testicle. All slides were air-dried, stained with modified May--Grünwald--Giemsa (MGG) stain and then examined under light microscope with 1000× magnifications. Spermatogenic cells such as, spermatogonia (Sg), primary spermatocytes, secondary spermatocytes, early spermatids (ab), late spermatids (cd) and spermatozoa, and Sertoli cells were counted. The spermatozoa percentage was expressed as spermatic index (SI) and the number of Sertoli cells, counted apart, was expressed as sertoli cell index (SEI). There was not any significant difference between the spermatogenic cell parameters obtained from the two types of slides, but SEI were significantly different in two types of smears. The results of the study provide support for the use of TFNA as a useful minimally invasive modality to identify different spermatogenetic cell classes in alpaca. Moreover, the possibility to standardize this method might provide a greater impulse to the clinical diagnostics of SAC male infertility.