Age-related changes in the hamster epididymis

Photoperiod-regulated mitophagy in the germ cells of Brandt's voles (Lasiopodomys brandtii)

Photoperiod is a pivotal factor in affecting testicular function and spermatogenesis in seasonal-breeding animals. Mitophagy is essential for spermatogenesis, but its association with seasonal photoperiods has not been studied extensively. To explore this, we exposed male Brandt's voles (Lasiopodomys brandtii) to long-photoperiod (LP, 16 h/day) and short-photoperiod (SP, 8 h/day) conditions from their embryonic stages. Our results indicated that testis weight, volume, and relative testes weight were all significantly increased in LP compared to SP. Additionally, blood testosterone levels were markedly higher in LP than SP. Histological examination revealed that seminiferous diameter and epithelium thickness were greater in LP, with an increased abundance of germ cell types and cell numbers compared to SP. RT-qPCR analysis showed that mitophagy-promoting genes, such as Pink1, Prkn, Tomm7, Mnf2, Lc3, Optn, Gabarap, and Nbr1 were all upregulated in LP. Fluorescence in situ hybridization indicated that Pink1 expression was present in spermatogonia in SP, while in LP, Pink1 expression extended to almost all germ cell types with significantly higher mean optical density. Prkn expression was found in all germ cell types in both LP and SP, with a significantly higher mean optical density of 10-week-old LP males. Transmission electron microscopy showed normal mitochondrial morphology with clear membranes in SP, while the LP group had reduced cristae in mitochondria and damaged mitochondria undergoing autophagy. This study suggests that mitophagy may be involved in the photoperiodic spermatogenesis in Brandt's voles, providing insights into the role of photoperiod in seasonal reproduction in wild animals.

Contribution of impaired autophagy, mitochondrial dysfunction and abnormal lipolysis to epididymal aging in mice

With the increase of the aged population in modern society, research on aging and aging-related diseases has attracted increasing attention. Unlike women, men experience changes gradually in the reproductive system during aging. The epididymis is an important organ for sperm maturation and storage, but less study has been conducted to investigate cellular senescence in aging epididymis and the corresponding influences on sperm. This study aims to explore cellular and molecular mechanisms underlying aging changes in epididymal tissues. Cellular senescence in the epididymis of 18-month-old C57BL/6 J mice was evaluated with SA (senescence-associated)-β-galactosidase staining and molecular markers such as P21 and Lamin B, compared to the 2-month-old young group. Western blot analysis and immunofluorescence staining were performed to examine the proteins expressions involved in AMPKα/SIRT1 pathway, autophagy/mitophagy, mitochondrial dynamics and lipolysis. The results showed that in old mice AMPKα/ SIRT1 pathway was downregulated with increased acetylation in the epididymal tissues. Reduced expressions of autophagy related genes and PINK1/PARK2 were detected as well as increased P62 protein level and decreased colocalization of LC3 and LAMP2, which indicated deficient autophagy and mitophagy occurred in aging epididymal tissues. Significant decreased expressions of MFN1, MFN2, p-DRP1(Ser637) and FIS1 showed an imbalance in mitochondrial dynamics in aging epididymal tissues. Additionally, intracellular lipid droplets accumulation occurred in epididymal epithelial cells in old mice, with reduced expressions of the lipolysis enzymes ATGL, HSL and Ascl4. Lipophagy impairment was further detected by minimal colocalization of lipid droplets with either LC3 or LAMP2 in the epididymal ductal epithelial cells of old mice. Our study provides new insights into the molecular mechanisms of impaired autophagy, imbalanced mitochondrial dynamics and disrupted lipolysis, which together contribute to senescent changes and may be detrimental to the epididymal function during aging.

Age-Dependent Variations in Functional Quality and Proteomic Characteristics of Canine (Canis lupus familiaris) Epididymal Spermatozoa

Increased male age is associated with a significant reduction in semen quality. Little is known about the sperm proteome changes resulting from the aging process. This study aimed to investigate the relationship between the functional quality and proteome of epididymal spermatozoa of dogs that were differing in age. The study was conducted on 30 male dogs that were divided into three age groups. G1—12 to 41 months old, G2—42 to 77 months old, and G3—78 to 132 months old. The sperm samples were assessed using a computer-assisted semen analysis (CASA). The epididymal sperm proteins were analyzed using gel electrophoresis (SDS-PAGE), nano-liquid chromatography coupled to quadrupole time of flight mass spectrometry (NanoUPLC-Q-TOF/MS) and bioinformatic tools. The sperm quality parameters were significantly lower in older dogs. NanoUPLC-Q-TOF/MS identification resulted in 865 proteins that were found in the G1, 472 in G2, and 435 in G3. There were seven proteins that were present in all three age groups, and four of them (ACTB, CE10, NPC2, CRISP2) showed significant changes among the studied groups. Age-dependent variations were detected in the sperm proteome composition and were related to important metabolite pathways, which might suggest that several proteins are implicated in sperm maturation and could be potential aging biomarkers.

Age-Related Decline of Male Fertility: Mitochondrial Dysfunction and the Antioxidant Interventions

Mitochondria are structurally and functionally unique organelles in male gametes. Apparently, as the only organelles remaining in mature sperm, mitochondria not only produce adeno-sine triphosphate (ATP) through oxidative phosphorylation (OXPHOS) to support sperm mobility, but also play key roles in regulating reactive oxidation species (ROS) signaling, calcium homeostasis, steroid hormone biosynthesis, and apoptosis. Mitochondrial dysfunction is often associated with the aging process. Age-dependent alterations of the epididymis can cause alterations in sperm mitochondrial functioning. The resultant cellular defects in sperm have been implicated in male infertility. Among these, oxidative stress (OS) due to the overproduction of ROS in mitochondria may represent one of the major causes of these disorders. Excessive ROS can trigger DNA damage, disturb calcium homeostasis, impair OXPHOS, disrupt the integrity of the sperm lipid membrane, and induce apoptosis. Given these facts, scavenging ROS by antioxidants hold great potential in terms of finding promising therapeutic strategies to treat male infertility. Here, we summarize the progress made in understanding mitochondrial dysfunction, aging, and male infertility. The clinical potential of antioxidant interventions was also discussed.

Effects of aging and oviductal hormones on testes, epididymides, and sperm of hamster

Purpose

Aging is a major cause of decreased fertility. Using hamster, we examined the effects of aging on testes, epididymides, and sperm. Additionally, we examined whether progesterone (P4), melatonin (Mel) and 5-hydroxytryptamine (5-HT) mitigated effects of aging on sperm.

Methods

Young (10-16 weeks), Adult (5-7 months), Aged (13-15 months), and Old (19-22 months) hamsters were used. Weights of bodies, testes, and epididymides were measured. Testes and epididymides were studied by histological microscopy. Sera were obtained to determine testosterone concentrations. Sperm were analyzed by video-microscopy.

Results

By aging, body weights increased but weights of testes and epididymides decreased. Most hamsters were normozoospermia, although several old hamsters were azoospermia. In testes and epididymides, desquamation and structures resembling residual bodies (SRRBs) were observed. Although desquamation was not always related to aging, SRRBs occurred by aging. Testosterone concentrations were not changed in normozoospermic hamsters, but it was significantly reduced in old azoospermic hamster. Aging significantly reduced sperm ability to exhibit hyperactivation. Additionally, aging significantly increased the straight-line velocity (VSL). P4, Mel, and 5-HT lessened the reduction in sperm hyperactivation and the increasing of VSL.

Conclusion

Aging reduces qualities of testes, epididymides, and sperm, and P4, Mel, and 5-HT recover reduced quality of sperm.

Age-Related Changes in the Testicular Morphophysiology of the Cane Rat (Thryonomys swinderianus)

This study evaluated age-related changes in the testicular morphophysiology of the cane rat (Thryonomys swinderianus) using histological, histochemical, and sex hormonal profile approaches. Twenty (20) pathogen-free male cane rats were used for the investigation. Cane rats were divided into four groups: prepubertal (≤4 months), pubertal (>4 ≤12 months), adult (>12 ≤30 months), and aged (>30 months) of 5 rats each. Blood was collected from the different cane rat groups and processed for sex serum hormonal levels. Testes were also excised and processed routinely for variations in histology, histochemistry (using Masson's trichrome [MT] and Periodic acid-Schiff [PAS]), and histomorphometric evaluations using GIMP2 software. Testosterone concentrations were significantly elevated (P < 0.05) in the prepubertal to adult, while there were no significant differences (P > 0.05) in this hormone between adult and aged. The concentrations of follicle-stimulating hormone (FSH) decreased significantly (P < 0.05) for prepubertal, pubertal, and adult, respectively. There were no significant differences (P > 0.05) between adult and aged for FSH and luteinizing hormone. Histologically, there were scanty interstitial cells, lack of patent lumen, and incomplete spermatogenetic cell series in prepubertal compared to other age groups. Testicular capsular (MT and PAS) staining intensity increased with age advancement, while in the parenchyma, remarkably high intensity was displayed by the pubertal compared to others. Seminiferous tubular and luminal diameters (LD) significantly (P < 0.05) increased with advancing age whereas epithelial height (EH) was markedly increased in pubertal relative to other groups. In conclusion, these sets of data have shown that reproductive activity is directly related to age and is at maximum in adult cane rat.

The process of testicular regression also impacts the physiology of the epididymis of the bat Molossus molossus, although with a delay in epididymal response due to sperm storage

Responsible for post-testicular maturation, concentration, protection and sperm storage, the epididymis is an organ that can be easily subdivided into three segments: caput, corpus and cauda. Each epididymal region displays different morphology and functions within the sperm maturation process. Despite the great importance of this organ, studies on its morphology and hormonal control in bats remain scarce. Thus, the aim of this study was to morphologically analyze the epididymis of the bat Molossus molossus (Chiroptera: Molossidae), in order to evaluate its morphological and morphometric variations, as well as some aspects of its hormonal control during the annual reproductive cycle. For this purpose, 60 sexually adult males were used in this study, comprising five specimens collected monthly for one year to form 12 sample groups. The epididymis was subjected to morphological, morphometric and immunohistochemical analyses. The results demonstrated that the processes of total testicular regression and posterior recrudescence suffered by M. molossus also impacts the physiology of the epididymis, however, a delay in the epididymal response is seen due to the storage of sperm. Similar to other mammals, the epididymis of M. molossus has a large predominance of principal and basal cells. The epididymal seasonal variations appear to be directly correlated to rainfall and photoperiod, but not to temperature. Meanwhile, epididymal physiology appears to be regulated, at least partially, by the expression of the androgen receptor in epithelial cells, which has agonist effects on cell proliferation.

Descrição e variação sazonal na histomorfometria epididimária de Dermanura cinerea (Chiroptera: Phyllostomidae) em um fragmento de Mata Atlântica no Nordeste do Brasil

RESUMO Esse estudo objetivou avaliar sazonalmente a histomorfometria do epidídimo de Dermanura cinerea (Gervais, 1856) em um fragmento de Mata Atlântica no nordeste do Brasil. Foram utilizados 18 espécimes machos adultos capturados por redes de neblina. As coletas ocorreram mensalmente ao longo de dezoito meses, durante duas noites consecutivas e os dados meteorológicos foram fornecidos pelo Instituto Nacional de Meteorologia. Depois de eutanasiados, os espécimes tiveram os epidídimos coletados e esses órgãos foram fixados e processados. As lâminas histológicas foram coradas por Hematoxilina - Eosina e analisadas em microscopia óptica. Os parâmetros morfométricos analisados foram as áreas do túbulo, do lúmen e do epitélio das regiões do segmento inicial, cabeça, corpo e cauda do epidídimo. Os dados histomorfométricos obtidos foram submetidos às análises no teste U de Mann-Whitney. Os resultados revelaram que D. cinerea apresentou espermatozoides em todas as regiões do epidídimo, exceto no segmento inicial. As maiores médias das áreas tubular, do lúmen e do epitélio nas quatro regiões, foram constatadas durante os meses secos. Portanto, D cinerea apresentou maior sensibilidade na região da cauda do epidídimo, ao longo dos meses com baixos índices pluviométricos. Isso indica que as condições ambientais apresentam considerável influência sobre a morfofisiologia epidídimária dessa espécie, sobretudo, em relação ao armazenamento de espermatozoides na cauda desse órgão, em área de Mata atlântica do nordeste brasileiro.

The Exacerbation of Aging and Oxidative Stress in the Epididymis of Sod1 Null Mice

There is growing evidence that the quality of spermatozoa decreases with age and that children of older fathers have a higher incidence of birth defects and genetic mutations. The free radical theory of aging proposes that changes with aging are due to the accumulation of damage induced by exposure to excess reactive oxygen species. We showed previously that absence of the superoxide dismutase 1 (Sod1) antioxidant gene results in impaired mechanisms of repairing DNA damage in the testis in young Sod1^−/− mice. In this study, we examined the effects of aging and the Sod^−/− mutation on mice epididymal histology and the expression of markers of oxidative damage. We found that both oxidative nucleic acid damage (via 8-hydroxyguanosine) and lipid peroxidation (via 4-hydroxynonenal) increased with age and in Sod1^−/− mice. These findings indicate that lack of SOD1 results in an exacerbation of the oxidative damage accumulation-related aging phenotype.

Effects of Estrogen Treatment on Aging in the Rat Epididymis

Previous studies from our laboratory demonstrated that estrogen signaling in the testis contributes to maintaining spermatogenesis in adult rats, and that estrogen treatment attenuated the age-associated decline in sperm production. The purpose of this study was to determine if epididymal function is also altered with age, and what effects estrogen treatment may have on the epididymis during aging. We compared untreated rats at 3 and 15 months of age to 18-month-old vehicle-treated and estrogen treated rats. In all four groups, tubule and lumen diameter of the cauda was significantly larger than more proximal regions of the epididymis. In the 3-, 15-, and 18-month-old treated animals, the epithelial cell height of the cauda was significantly shorter than that of more proximal regions. The caput cell height was shorter at 18 months compared to 3 months but this was not seen in estrogen treated animals. Thus, estrogen appears able to prevent some age related changes in epididymal morphology. Sperm transit time through the distal cauda was significantly delayed with aging. Estrogen treatment prevented this delay, indicating that sperm transit through the epididymis is an estrogen regulated function. Differences in estradiol and testosterone concentrations were observed between 3- and 15-month-old animals, but no further differences were noted between treated or untreated animals at 18 months. Interestingly, expression of androgen receptor and estrogen receptor alpha were similar between ages and treatments. Collectively, these results suggest epididymal morphology and function are affected by aging and estrogen treatment. Anat Rec, 302:1447-1457, 2019. © 2018 Wiley Periodicals, Inc.

Atrazine affects the morphophysiology, tissue homeostasis and aromatase expression in the efferent ductules of adult rats with mild alterations in the ventral prostate

The widely used herbicide atrazine is a potent endocrine disruptor known to cause increased aromatase expression and transient increase in testicular weight followed by remarkable testis atrophy. However, whether the effects of atrazine on the testes are primary or secondary to dysfunctions in other components of male reproductive tract remains unknown. Given the high sensitivity of the efferent ductules to estrogen imbalance and the similarity to alterations previously described for other disruptors of these ductules function, and the testicular alterations observed after atrazine exposure, we hypothesized that the efferent ductules could be a target for atrazine. Herein we characterized the efferent ductules and the ventral prostate of adult Wistar rats treated with 200 mg/kg/day of atrazine for 7, 15, and 40 days. Additionally, we evaluated if the effects of atrazine in these organs could be reduced after discontinuation of the treatment. Atrazine exposure resulted in mild effects on the ventral prostate, but remarkable alterations on the efferent ductules, including luminal dilation, reduced epithelial height, and disruption of the epithelial homeostasis, which coincides with increased aromatase expression. Together with our previous data, these results suggest that at least part of the testicular effects of atrazine may be secondary to the alterations in the efferent ductules.

Potential confounding factors in measurement of specific cell-free seminal mRNAs and microRNAs derived from human reproductive organs

Cell-free seminal RNA (cfs-RNA) is mixed transcripts derived from male reproductive organs, and is potential biomarker for the research and diagnosis of male reproductive-related diseases. However, some clinical factors, including age, asymptomatic Ureaplasma urealyticum (UU) infection, scrotal heat stress, abstinence period, and the storage condition of semen samples, may interfere with sperm parameters and the measurement of seminal biomarkers. Accordingly, this study was designed to evaluate the effect of above clinical factors on the measurement of cfs-RNA, aiming to lay a foundation for its research use and potential clinical application. Semen samples were collected according to the selected clinical factors. Cell-free seminal plasma was obtained by centrifugation and total RNA was extracted with TRIzol LS. Selective male reproductive organ-specific cfs-mRNAs and cfs-miRNAs were quantified by quantitative real-time PCR. The concentration and total amount of cfs-mRNAs and cfs-miRNAs in one ejaculate were calculated and compared. ACTB, DDX4 (testis-specific), WFDC9 (epididymis-specific), and miR-514a-3p (testis-specific) significantly increased after scrotal heat stress. SEMG1 (seminal vesicle-specific) showed declining tendency with the prolonged abstinence period. Age, asymptomatic UU infection, and the storage condition showed no significant impact on the measurement of cfs-RNA. These results indicate that scrotal heat stress significantly interfere with the selected cfs-RNA derived from the testis and epididymis, and abstinence period may affect the yield of cfs-mRNA from seminal vesicle, while other clinical factors has no significant impact on the measurement. Thus, heat exposure and abstinence period should be considered for the cfs-RNA measurement in its research or clinical application.

Cellular changes in the hamster testicular interstitium with ageing and after exposure to short photoperiod

The aim of this study was to evaluate the cellular changes that occur in the hamster testicular interstitium in two very different physiological situations involving testicular involution: ageing and exposure to a short photoperiod. The animals were divided into an ‘age group’ with three subgroups – young, adult and old animals – and a ‘regressed group’ with animals subjected to a short photoperiod. The testicular interstitium was characterised by light and electron microscopy. Interstitial cells were studied histochemically with regard to their proliferation, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick end labelling (TUNEL+) and testosterone synthetic activity. We identified two types of Leydig cell: Type A cells showed a normal morphology, while Type B cells appeared necrotic. With ageing, pericyte proliferation decreased but there was no variation in the index of TUNEL-positive Leydig cells. In the regressed group, pericyte proliferation was greater and TUNEL-positive cells were not observed in the interstitium. The testicular interstitium suffered few ultrastructural changes during ageing and necrotic Leydig cells were observed. In contrast, an ultrastructural involution of Leydig cells with no necrosis was observed in the regressed group. In conclusion, the testicular interstitium of Mesocricetus auratus showed different cellular changes in the two groups (age and regressed), probably due to the irreversible nature of ageing and the reversible character of changes induced by short photoperiod.

Oxidative stress in testis of animals during aging with and without reproductive activity

The free radical theory of aging postulates that an imbalance between reactive oxygen species (ROS) and reactive nitrogen species (RNS) and antioxidant defenses is important in senescence. To address this issue and gain insight into the aging process, we have evaluated the antioxidant defenses and have assessed oxidative damage in testis tissues in aging male rats. In order to relate aging and reproduction, animals with and without reproductive activity were studied. In reproductive animals the results showed a progressive increase in antioxidant enzyme activity until 12 months of age followed by an abrupt fall at 24 months. In non-reproductive animals, antioxidant activity was stable through 12 months of age, but again, fell abruptly at 24 months of age. In addition, increased aconitase activity and increased testosterone levels were found among reproductively active animals. The data demonstrate the existence of metabolic differences in testis of reproductively experienced animals and reproductively naïve animals.

Effects of Photoperiod on Epididymal and Sperm Morphology in a Wild Rodent, the Viscacha (Lagostomus maximus maximus)

The viscacha (Lagostomus maximus maximus) is a seasonal South American wild rodent. The adult males exhibit an annual reproductive cycle with periods of maximum and minimum gonadal activity. Four segments have been identified in the epididymis of this species: initial, caput, corpus, and cauda. The main objective of this work was to relate the seasonal morphological changes observed in the epididymal duct with the data from epididymal sperm during periods of activity and gonadal regression using light and scanning electron microscopy (SEM). Under light and electron microscopy, epididymal corpus and cauda showed marked seasonal variations in structural parameters and in the distribution of different cellular populations of epithelium. Initial and caput segments showed mild morphological variations between the two periods. Changes in epididymal sperm morphology were observed in the periods analyzed and an increased number of abnormal gametes were found during the regression period. During this period, anomalies were found mainly in the head, midpiece, and neck, while in the activity period, defects were found only in the head. Our results confirm that the morphological characteristics of the epididymal segments, as well as sperm morphology, undergo significant changes during the reproductive cycle of Lagostomus.

Proliferation and apoptosis in aged and photoregressed mammalian seminiferous epithelium, with particular attention to rodents and humans

Imbalances in the proliferation and apoptosis processes are involved in numerous epithelial alterations. In the seminiferous epithelium, normal spermatogenesis is regulated by spermatogonia proliferation and germ cell apoptosis, and both processes are involved in diverse pathological alterations of the seminiferous epithelium. Other physiological phenomena including aging and short photoperiod, in which apoptosis and proliferation seem to play important roles, cause testicular changes. Aging is accompanied by diminished proliferation and increased apoptosis, the latter occurring in specific states of the seminiferous cycle and considered the cause of epithelium involution. However, there is no clear evidence concerning whether proliferation decreases in the spermatogonia themselves or is due to an alteration in the cell microenvironment that surrounds them. As regards the factors that regulate the process, the data are scant, but it is considered that the diminution of c-kit expression in the spermatagonia, together with the diminution in antiapoptotic factors (Bcl-x(L))) of the intrinsic molecular pathway of apoptosis play a part in epithelial regression. A short photoperiod, especially in rodents, produces a gradual involution of the seminiferous epithelium, which is related with increased apoptosis during the regression phase and a diminution of apoptosis during recrudescence. Proliferative activity varies, especially during the total regression phase, when it usually increases in the undifferentiated spermatogonia. In other species showing seasonal reproduction, however, decreased proliferation is considered the main factor in the regression of the seminiferous epithelium. Little is known about how both phenomena are regulated, although data in rodents suggest that both the intrinsic and extrinsic pathways of apoptosis contribute to the increase in this process. In conclusion, regression of the seminiferous epithelium in physiological situations, as in many pathological situations, is a result of alterations in equilibrium between the proliferation and apoptosis of germinal cell types. However, both physiological phenomena showed important differences as regard proliferation/apoptosis and their regulation pathways, probably as a result of their irreversible or reversible character.

Secondary sexual characters and sperm traits in coho salmon Oncorhynchus kisutch

A study was undertaken to examine secondary sexual characters (spawning colouration and overall body size) in relation to sperm metrics in one alternative reproductive tactic of coho salmon Oncorhynchus kisutch: large hooknose males that spawn in dominance-based hierarchies. Males with less intense red spawning colouration had higher sperm velocities than males with darker red spawning colouration. There was no relationship between male body size and sperm metrics. These results suggest that within an alternative reproductive tactic, variation in sperm competition intensity may select for a trade-off between investment in sexual colouration and sperm quality.

Reduced endogenous estrogen delays epididymal development but has no effect on efferent duct morphology in boars

The study presented herein was designed to test the hypothesis that reduced endogenous estrogen in the boar alters efferent duct morphology, epididymal morphology, and steroid receptor expression. Twenty-eight littermate pairs of boars were treated with Letrozole, an aromatase inhibitor, or with vehicle from 1 week of age until castration at 2 through 8 months. Efferent ducts and epididymides were examined for morphological development and steroid receptor expression. Efferent duct morphology was not different between control and Letrozole-treated animals at any examined age. Androgen receptor (AR), estrogen receptor α (ERα), and β (ERβ) were expressed in the epithelial cells of the efferent ducts at all ages; expression was similar in control and treated animals. Morphological development of the caput and corpus was delayed in Letrozole-treated animals, but this delay was transient since morphology was similar between control and treated animals at 8 months. The cauda did not show a delay in development, but was more developed in treated animals at 2 months. AR, ERα, and ERβ were expressed in all three epididymal regions; no difference was observed between control and treated animals. In summary, estrogen appears to be important for development of the epididymis; however, the cauda may be regulated differently than the caput and corpus. Results for the efferent ducts suggest that the normally high endogenous estrogens are not required for regulation of fluid reabsorption in the boar. It also suggests that any ER activation required for maintenance of efferent duct morphology and function is normal in Letrozole-treated boars.

Association between age and epididymal and accessory sex gland function and their relation to sperm motility

Increased male age has been associated with significant reduction in pregnancy rates. This study investigated the association between age, the function of epididymal and accessory sex glands, and their relation to sperm motility. Ejaculates from 498 men assessed for infertility were analysed according to WHO [1999] guidelines. Seminal markers of epididymal (neutral alpha-glucosidase (NAG)), prostatic (prostate-specific antigen (PSA) and zinc), and seminal vesicle function (fructose) were measured. Four groups according to age were defined: G(21-30) (21-30 years), G(31-40) (31-40 years), G(41-50) (41-50 years), and G(>50) (51-66 years). Percentage progressive motility was significantly lower in G(>50) compared with G(21-30). NAG, PSA, zinc, and fructose were significantly lower in G(>50) compared with G(21-30). In a multiple regression analysis model, NAG and PSA showed positive significant association with percentage progressive motility. The opposite trend was found regarding zinc. No association between fructose and percentage progressive motility was shown. In this cross-sectional study, declined sperm motility observed in men over 50 years of age might be due to age-dependent changes in epididymal and accessory sex gland function.

Epididymis of viscacha (Lagostomus maximus maximus): morphological changes during the annual reproductive cycle

Little is known about morphological changes in the epididymis in relation to the natural photoperiod or their influence on sperm maturation. The viscacha is a seasonal rodent living in the Southern Hemisphere. The adult males exhibit an annual reproductive cycle with periods of maximum gonadal activity and gonadal regression. In this work, we studied seasonal variations in the morphology and cellular population of the epididymis during both periods, and we compared these results with those recorded at the testicular level. Epididymides were removed and studied by light microscopy. Measurements of luminal diameter, epithelial height, thickness of the lamina propria, and relative cellular distribution were performed. Analysis of variance (ANOVA) or nonparametric ANOVA was used to compare the results. Striking quantitative and qualitative changes were observed. Epididymides in periods of gonadal regression showed a significant decrease in luminal diameter and epithelial height in cauda, while the thickness of the lamina propria increased. In the epididymal corpus, the number of clear cells increased, and the cytoplasm of principal cells showed numerous giant vacuoles. During the active period, the number of halo cells increased and the cytoplasm of these cells was filled with dense bodies. In conclusion, the epididymis of the viscacha exhibits important seasonal morphological changes throughout annual reproductive cycle. The epididymal corpus and cauda segments appeared to be the segments most sensitive to seasonal cyclical variations of the external environment. We therefore postulate that the epididymal morphology of the viscacha probably could be regulated by the natural photoperiod.