Andrology: Changes in chromatin condensation of human spermatozoa during epididymal transit as determined by flow cytometry

Inasmuch as caput epididymal and even testicular spermatozoaare now being used to generate pregnancies by direct injectioninto the oocyte, differences in the chromatin of spermatozoafrom proximal and distal locations in the epidldymis were studied.Acridine Orange staining was used to investigate chromatin structurein human spermatozoa which had left the testis and were undergoingmaturation in the epididymis. Measurement of green and red fluorescenceIntensities of human spermatozoa by flow cytometry demonstrateda decrease in binding of Acridine Orange to DNA as the spermatozoatraversed the epididymis. Using spermatozoa from the cauda epididymisas the standard, the percentages of spermatozoa from the efferentduct, proximal corpus epididymis, midcorpus epididymis, distalcorpus epididymis, proximal cauda epidldymis and distal caudaepididymis that had matured with regard to chromatin condensationwere 28 ± 5, 39 ± 3, 49 ± 5, 64 ±5, 69 ± 6 and 74 ± 4% respectively. It may beconcluded that eggs fertilized by ejaculated spermatozoa receivea more highly condensed form of chromatin than that receivedby eggs Inseminated with proximal epididymal or testicular spermatozoa.     

ILA 147 immunoreactivity of the bull spermatozoa membrane during epididymal maturation

A cytochemical quantitative study was carried out to detect immunostaining of bull spermatozoa during epididymal maturation using an ILA 147 monoclonal antibody and a standard immunoperoxidase method. This antibody recognizes a bovine panleukocyte determinant. Microdensitometric measurements were made on spermatozoa collected from different sites of the male genital tract (caput, corpus and cauda epididymidis and ductus deferens). On the basis of ILA 147 staining, at least 5 subpopulations of sperm cells from each site of the genital tract were found. These subpopulations showed: 1) immunostaining in the acrosome domain and in the cytoplasmic droplet in a proximal position; 2) immunostaining in the acrosome domain and in the distal cytoplasmic droplet; 3) immunostaining in the acrosomal region and lack of a cytoplasmic droplet; 4) immunostaining only in the cytoplasmic droplet; 5) lack of a cytoplasmic droplet and absence of staining of the head. The possible relationship between the presence of ILA 147 on the sperm head and the maturation process was evaluated, and we suggest that the most significant changes in ILA 147 expression occur in the corpus epididymidis. The absence of immunocytochemical staining in some spermatozoa may be related to plasma membrane damage due to spontaneous peroxidative damage of lipids.     

Changes in lipids and membrane anisotropy in human spermatozoa during epididymal maturation

Previously it was demonstrated that immature and immotile human spermatozoa from the caput epididymides developed a good progressive motility after in-vitro stimulation with phosphatidylcholine (PC). In order to define the role of PC and membrane anisotropy in epididymal maturation and to determine the exact lipid composition of human spermatozoa during epididymal maturation, spermatozoa from seven epididymides from patients who underwent orchiectomy because of prostatic cancer were investigated. Lipids were determined by high- performance thin-layer chromatography and gas chromatography. Membrane anisotropy was measured by fluorescence polarization. The ratio between PC and phosphatidylserine (PS) plus phosphatidyl ethanolamine (PE) plus sphingomyelin (SM) was significantly higher in spermatozoa from the cauda compared to those from the caput and corpus. This was due to an increase of PC and a decrease of the concentration of PS plus PE plus SM. With regard to fatty acids, those with saturated chains predominated in caput spermatozoa while the highest concentration of unsaturated long-chain fatty acids was in cauda spermatozoa. A lower membrane anisotropy of cauda spermatozoa compared with caput or corpus spermatozoa was found. In conclusion, during epididymal maturation human spermatozoa integrate lipids, particularly PC, which is strongly associated with the induction of progressive motility. A change in the pattern of fatty acids and a decrease in the cholesterol/phospholipid molar ratio cause a decrease in membrane anisotropy in cauda spermatozoa.      

The coiled tail of the round-headed spermatozoa appears during epididymal passage in GOPC-deficient mice

Male mice deleting the gene encoding GOPC (Golgi-associated PDZ- and coiled-coil motif-containing protein) are infertile, showing globozoospermia with a coiled tail (Yao et al., 2002). We confirmed how and where tail anomalies were produced in spermatids and epididymal spermatozoa by light and electron microscopy. During spermiogenesis, tail formation occurred normally, but a defect was found at the posterior ring. Thereafter, remarkable sperm tail deformations were induced during epididymal passage. In the proximal caput epidiymidis, the tails remained normal and straight, but most of them coiled around the nucleus in the cauda epididymidis. Coiling is presumed to occur with the migration of the cytoplasmic droplet by the absence of the posterior ring. The connecting piece of the coiled tail was often dislocated or separated from the implantation fossa. Many mitochondria were separated from the outer dense fibers (ODFs) and formed a stratified mitochondrial sheath. Due to this, the distal part of the midpiece became bared of the mitochondrial sheath. The bared ODFs were often bent and disorganized. Tail deformities are attributed to weak or incomplete adhesion between the following structures: 1) plasma membrane and nuclear envelope at the posterior ring, 2) connecting piece and implantation fossa, and 3) mitochondria and ODFs. These defects result in a coiled tail, tail dislocation from the implantation fossa, and the stratified mitochondrial sheath accompanying bared ODFs in the midpiece, respectively. Thus the posterior ring is significant in preventing coiled tail formation. The GOPC-deficient spermatozoa provide a valuable model not only for head but also for tail anomalies.     

Viability of postmortal epididymal mouse spermatozoa during long-term hypothermic storage and cryopreservation

The study examined the effect of long-term hypothermic (4°C) storage of mouse carcasses on motility, cell membrane damage, in vitro survival and capacitation of epididymal spermatozoa before and after cryopreservation. It was shown that the number of spermatozoa with rectilinear forward motion decreased with increasing storage time. There were no significant changes in the total sperm motility and integrity of their plasmalemma. Pronounced effects of hypothermia and long-term storage of the mouse carcasses on cryocapacitation of spermatozoa during cryoconservation were demonstrated.     

Nuclear zinc in human epididymal and ejaculated spermatozoa

Sperm nuclear zinc content (expressed as zinc/phosphorus and zinc/sulphur ratios) was determined with X-ray microanalysis in individual, air-dried, epididymal spermatozoa from elderly men, and in ejaculated spermatozoa from healthy donors. Ejaculated sperm nuclei contained (also after treatment with sodium dodecyl sulphate) more zinc than epididymal spermatozoa. The results indicate that the human spermatozoon accumulates zinc from the prostatic fluid upon ejaculation.     

Change in intramembranous particle distribution in epididymal spermatozoa of the boar

Membranes of boar spermatozoa from different regions of the epididymis and after ejaculation were studied by the freeze-fracture replica technique. The ordered pattern of the intramembranous particles of spermatozoan plasma membranes was different in the five arbitrary zones of the epididymis and in the semen. A distinctive ordered pattern was absent in zone 1, which is the proximal segment of the epididymis. In zone 2, paired parallel rows of the particles were present in the plasma membrane over the acrosomal region. This parallel arrangement was not present in zone 3 spermatozoa. Anterior to the posterior ring, cords formed by packed particles were apparent in zone 2 spermatozoa and reached their maximum prominence in zone 3, and persisted in zones 4 and 5 and in the semen. The plasma membrane over the marginal ridge of the acrosome had a hexagonal array of particles only in zones 4 and 5 spermatozoa. A similar pattern appeared on the post-acrosomal region of spermatozoa in zone 5 and in the semen. The plasma membrane of the middle piece had a rectilinear arrangement of the particles in zone 2 spermatozoa in which the migration of the cytoplasmic droplet was complete. Rudiments of the rectilinear arrangement persisted in spermatozoa in zones 4 and 5 and in the semen. These changes are discussed in relation to sperm maturation in the epididymis. The acrosomal membrane had a hexagonal arrangement of particles in the equatorial segment. The marginal ridge of the outer acrosonal membrane had parallel rows of intramembranous particles. The organization of the acrosomal membrane particles did not change during the epididymal passage of boar spermatozoa.     

Microphotometric study of glucose-6-phosphate dehydrogenase activity in epididymal spermatozoa during spontaneous lipid peroxidation

Mammalian spermatozoa are highly sensitive to lipid peroxidation and the glutathione peroxidase/reductase system provides an effective defense against oxidative damage to different degree in different species. Rabbit spermatozoa rely on superoxide dismutase as the primary enzymatic defense against lipid peroxidation and contain only low detectable endogenous glutathione reductase activity while in mouse spermatozoa the glutathione system is the major protective enzyme against cell damage by autoxidation. We describe a cytochemical quantitative assay for glucose-6-phosphate dehydrogenase activity in rabbit and mouse spermatozoa undergoing spontaneous lipid peroxidation during in vitro incubation. Microdensitometric measurements were made by a Vickers M85 a scanning microdensitometer at lambda 585 nm wavelength. Our findings suggest that in mouse spermatozoa, the enhanced glutathione reductase and peroxidase activities induced by the spontaneous lipid peroxidation increases NADPH production from the pentose phosphate shunt, while in rabbit spermatozoa, NADPH production is much lower.     

Morphological changes in the pancreas during the development of experimental diabetes

Summary Repeated administration of small doses of alloxan (5 mg 100 g of body weight) caused diabetes to develop gradually in albino rats. A direct relationship could then be observed between the degree of disturbance of the carbohydrate metabolism and the extent of the morphological changes in the pancreas: as the blood sugar concentration in the islets of Langerhans rose, the death rate of the beta-cells also rose, and new gamma-cells were formed which developed from the plasmodium. Most of the medium sized and small islets were found in diabetic rats. Changes were found in the acinous cells of the peri-insular zones, indicating their possible transformation into islets.(Presented by Active Member AMN SSSR S. V. Anichkov) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 54, No. 12, pp. 103–105, December, 1962     

Morphological changes in human myocardium during permanent pacing

Summary We have reviewed 74 cases of patients with permanent pacing, using different types of pacing leads in order to determine what morphological changes are produced by this therapy. Macroscopic examination of the heart was performed and slides at the implantation site reviewed when available.Severe chronic inflammation, scarring and a myocardial response were the prominent findings. From a strictly morphological aspect, the initial trauma at implantation time, the chronic foreign body reaction and myocardial response to chronic trauma, are both much less significant in endovenous than in epimyocardial pacing.     

Morphological changes in nerve cells during normal aging

During normal aging, widespread loss of nerve cells does not occur. Neuronal loss is limited to restricted regions of the nervous system and is slight (probably no more than 10%). The commonest age-related structural changes undergone by nerve cells are as follows: dendrites decrease in number and length and many dendritic spines are lost; axons decrease in number and their myelin sheaths may become less compact and undergo segmental demyelination followed by remyelination; and significant loss of synapses occurs. These changes probably make a significant contribution to the behavioral impairment and cognitive decline that often accompany normal aging.     

Morphological changes in the kidneys during nonspecific ulcerative colitis]

Light microscopy, immunohistochemical examinations and electron microscopy of kidney biopsies showed the different localization of immune complexes in the glomeruli (subepithelial, intramembraneous, subendothelial, and mesangial immune complexes) and various forms of materialization of their harmful effect (induction of immune inflammation or immunosuppression) to be determined by the involvement in phagocytosis and reparation reactions of either podocytes or mesangial and endothelial cells and also hematogenous elements. Therefore, podocyte, mesangioendothelial and podocyte-mesangioendothelial ways of morphogenesis of immunocoplex glomerulonephritis may be distinguished. Each of them is associated with the development of certain clinico-morphological forms of immunocomplex glomerulonephritis which should be considered as distinct entities.     

Morphological observations on the mesodermal cells in the 8 day opossum embryo

Cells of the mesodermal layer of the 8 day opossum were examined by scanning and transmission electron microscopy after removal of the ectoderm. The mesodermal layer is formed by a multilayered network of large somewhat flattened, stellate-shaped cells, whose broad surfaces usually lie parallel to the external surface of the embryo. The mesodermal cells show numerous cytoplasmic processes which often appear as long delicate threads that may branch. The processes may course for considerable distances and establish contact with adjacent mesodermal cells. Contact points between processes, processes and cells, and between adjacent cell bodies showed junctional complexes. Most of the junctional complexes appeared morphologically similar to the nexus (communicating) type. Occasional desmosome-like junctions also were observed. Extracellular fibers were not observed.