Proximal Corpus Research Articles

PARTIAL UNILATERAL PENILE THROMBOSIS: MAGNETIC RESONANCE IMAGING AND MANAGEMENT

A 44-year-old man presented with severe pain and swelling of the left proximal corpus cavernosum 3 days in duration. He reported an extended bicycle ride of approximately 80 miles the day before the onset of symptoms. Penile trauma or abnormalities with urination or erection were not reported. Complete blood count, electrolytes, coagulation profile and hemoglobin electrophoresis revealed no signs of infection or hematological disease. On physical examination a firm, painful mass was palpated in the left proximal corpus cavemo-

Beta-Hexosaminidase immunolocalization and alpha- and beta-subunit gene expression in the rat testis and epididymis.

beta-hexosaminidase is an essential lysosomal enzyme whose absence in man results in a group of disorders, the G(M2) gangliosidoses. beta-hexosaminidase activity is many times higher in the epididymis than in other tissues, is present in sperm, and is postulated to be required for mammalian fertilization. To better understand which cells are responsible for beta-hexosaminidase expression and how it is regulated in the male reproductive system, we quantitated the mRNA expression of the alpha- and beta-subunits of beta-hexosaminidase and carried out immunocytochemical localization studies of the enzyme in the rat testis and epididymis. beta-hexosaminidase alpha-subunit mRNA was abundant and differentially expressed in the adult rat testis and epididymis, at 13- and 2-fold brain levels, respectively. In contrast, beta-subunit mRNA levels in the testis and epididymis were 0.3- and 5-fold brain levels. During testis development from 7-91 postnatal days of age, testis levels of alpha-subunit mRNA increased 10-fold and coincided with the appearance of spermatocytes and spermatids in the epithelium; in contrast, beta-subunit mRNA was expressed at low levels throughout tests development. In isolated male germ cells, beta-hexosaminidase alpha-subunit expression was most abundant in haploid round spermatids, whereas the beta-subunit mRNA was not detected in germ cells. Within the epididymis both alpha- and beta-subunit mRNA concentrations were highest in the corpus, with 1.5-fold and 9-fold initial segment values, respectively. Light microscopic immunocytochemistry revealed that beta-hexosaminidase was localized to Sertoli cells and interstitial macrophages in the testis. In the epididymis, beta-hexosaminidase staining was most intense in narrow cells in the initial segment, principal cells in the caput and proximal corpus, and clear cells throughout the duct. Electron microscopic immunocytochemistry revealed that beta-hexosaminidase was predominantly present in lysosomes in Sertoli and epididymal cells. The cellular and regional specificity of beta-hexosaminidase immunolocalization suggest an important role for the enzyme in testicular and epididymal functions.

Treatment of Partial Priapism With an Intracavernous Injection of Etilefrine

To the Editor. —Partial priapism affects the proximal penis and is rare. Only 7 such cases have been reported,1and all have been treated surgically. Etilefrine, a sympathomimetic drug available in much of Europe but not the United States, has been used as an intracavernous injection in the treatment of classic priapism.2,3This is the first report of successful treatment of partial priapism by an intracavernous injection of the vasoactive drug etilefrine. Report of a Case. —A 29-year-old man presented with a perineal mass causing discomfort. The symptoms began 4 days prior to admission and were associated with impotence. No trauma or other unusual event was reported. He gave no history of similar episodes and denied taking drugs known to cause priapism.2 Physical examination revealed a painless perineal mass of elastic consistency involving the penoscrotal junction and extending along the right proximal corpus cavernosum. The distal penis

Posttesticular development of spermatozoa of the tammar wallaby (Macropus eugenii).

Tammar wallaby spermatozoa undergo maturation during transit through the epididymis. This maturation differs from that seen in eutherian mammals because in addition to biochemical and functional maturation there are also major changes in morphology, in particular formation of the condensed acrosome and reorientation of the sperm head and tail. Of spermatozoa released from the testes, 83% had a large immature acrosome. By the time spermatozoa reached the proximal cauda epididymis 100% of sperm had condensed acrosomes. Similarly 86% of testicular spermatozoa had immature thumb tack or T shape head-tail orientation while only 2% retained this immature morphology in the corpus epididymis. This maturation is very similar to that reported for the common brush tail possum, Trichosurus vulpecula. However, morphological maturation occurred earlier in epididymal transit in the tammar wallaby. By the time spermatozoa had reached the proximal cauda epididymis no spermatozoa had an immature acrosome and thumbtack orientation. Associated with acrosomal maturation was an increase in acrosomal thiols and the formation of disulphides which presumably account for the unusual stability of the wallaby sperm acrosome. The development of motility and progressive motility of tammar wallaby spermatozoa is similar to that of other marsupials and eutherian mammals. Spermatozoa are immotile in the testes and the percentage of motile spermatozoa and the strength of their motility increases during epididymal transit. During passage through the caput and corpus epididymis, spermatozoa first became weakly motile in the proximal caput and then increasingly progressively motile through the corpus epididymis. Tammar wallaby spermatozoa collected from the proximal cauda epididymis had motility not different from ejaculated spermatozoa. Ultrastructural studies indicated that acrosomal condensation involved a complex infolding of the immature acrosome. At spermiation the acrosome of tammar wallaby spermatozoa was a relatively large flat or concave disc which projected laterally and anteriorly beyond the limits of the nucleus. During transit of the epididymal caput and proximal corpus the lateral projections folded inwards to form a cup like structure the sides of which eventually met and fused. The cavity produced by this fusion was lost as the acrosome condensed to its mature form as a small button-like structure contained within the depression on the anterior end of the nucleus. During this process the dorsal surface of the immature acrosome and its outer acrosomal membrane and overlying plasma membrane were engulfed into the acrosomal matrix. This means that the dorsal surface of the acrosomal region of the testicular tammar wallaby sperm head is a transient structure. The dorsal acrosomal surface of the mature spermatozoon appears ultrastructurally to be the relocated ventral surface of the acrosomal projections which previously extended out beyond the acrosomal depression on the dorsal surface of the nucleus of the immature spermatozoon.

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

Inasmuch as caput epididymal and even testicular spermatozoa are now being used to generate pregnancies by direct injection into the oocyte, differences in the chromatin of spermatozoa from proximal and distal locations in the epididymis were studied. Acridine Orange staining was used to investigate chromatin structure in human spermatozoa which had left the testis and were undergoing maturation in the epididymis. Measurement of green and red fluorescence intensities of human spermatozoa by flow cytometry demonstrated a decrease in binding of Acridine Orange to DNA as the spermatozoa traversed the epididymis. Using spermatozoa from the cauda epididymis as the standard, the percentages of spermatozoa from the efferent duct, proximal corpus epididymis, midcorpus epididymis, distal corpus epididymis, proximal cauda epididymis and distal cauda epididymis that had matured with regard to chromatin condensation were 28 +/- 5, 39 +/- 3, 49 +/- 5, 64 +/- 5, 69 +/- 6 and 74 +/- 4% respectively. It may be concluded that eggs fertilized by ejaculated spermatozoa receive a more highly condensed form of chromatin than that received by eggs inseminated with proximal epididymal or testicular spermatozoa.

Surface localization of P34H an epididymal protein, during maturation, capacitation, and acrosome reaction of human spermatozoa.

During epididymal transit, spermatozoa acquire new surface antigens that are involved in the acquisition of their fertilizing ability. We have previously described a 34-kDa (P34H) human epididymal sperm protein that shows antigenic and functional homologies with the hamster P26h. P34H is localized on the acrosomal cap of human spermatozoa and has been proposed to be involved in the interaction with the zona pellucida. The aim of this study was to document the expression of P34H on the sperm surface during transit along the male and female genital tracts. Immunohistochemical techniques were performed on human testes and epididymides by means of an antiserum specific for P34H. No labelling was detected on those spermatozoa found within the seminiferous tubules or in the vasa efferentia. P34H first appeared in the caput epididymidis and was restricted to the acrosomal cap. Signal intensity then increased considerably from the proximal corpus to the cauda region of the epididymis. After ejaculation, the same pattern of P34H distribution was observed, but the intensity was much lower than that characterizing the cauda epididymal spermatozoa. Strong labeling was restored after incubation in B2 medium and was maximal after 5 h of capacitation. After acrosomal exocytosis induced by a Ca2+ ionophore, the percentage of P34H-labeled spermatozoa decreased proportionally to the number of acrosome-reacted spermatozoa as determined by Pisum sativum-fluorescein isothiocyanate (FITC) labeling. P34H appeared to be strongly anchored to the sperm plasma membrane during epididymal transit as indicated by the requirement for detergent to extract this surface antigen from ejaculated spermatozoa. This confirms the importance of P34H binding to the sperm plasma membrane during epididymal maturation. We have previously proposed that P34H is involved in sperm-zone pellucida interaction. The appearance and accumulation of P34H on the sperm plasma membrane during epididymal maturation, followed by its inaccessibility associated with ejaculation, its unmasking during capacitation, and finally its elimination after the acrosome reaction, are in agreement with te proposed function of this sperm antigen.

Maturation of sperm motility in the epididymis of the common marmoset (Callithrix jacchus) and the cynomolgus monkey (Macaca fascicularis).

The acquisition by spermatozoa of the capacity for movement upon liberation from the epididymal duct into buffer is one of the obvious changes associated with sperm maturation and, hence, studies of sperm kinematics might provide good indices for sperm maturation. Profiles of development in the movement pattern of spermatozoa taken from six regions of the epididymis were established in marmoset and cynomolgus monkeys using computer-assisted sperm analysis. Motion of spermatozoa from initial regions was sluggish and irregular, then developed in the more distal region into erratic movement effected by an increase in the vigour of flagellation as reflected by curvilinear velocity. The tendency of immature spermatozoa to display circular motion was more common in the marmoset than in the cynomolgus monkey. In the marmoset the most drastic changes in percentage motility and kinematic parameters of spermatozoa occurred between the distal caput and the proximal corpus; maximal values for these parameters were found around the distal corpus epididymis. For the cynomolgus spermatozoa the sharpest gain in percentage motility was also achieved between the caput and proximal corpus epididymis, but with full kinematic development in the proximal cauda epididymis. These maturational changes were not synchronous among spermatozoa from the same site as they moved along the epididymis, as reflected in the heterogeneity of each sample in the kinematic properties of individual spermatozoa, especially those from the proximal corpus epididymis. The maturational profiles in the monkeys are comparable to the situation in the human, for which they may provide a useful model.

Molecular cloning and characterization of EPI-1, the major protein in chimpanzee (Pan troglodytes) cauda epididymal fluid.

A 27-kDa glycoprotein comprises approximately 20% of the total protein in chimpanzee (Pan troglodytes) cauda epididymal fluid. Polyclonal antibodies generated against this glycoprotein react with 27- and 25-kDa components in chimpanzee cauda epididymal fluid and in human, gorilla, chimpanzee, and monkey seminal fluid. According to microsequencing, the 27- and 25-kDa components (chimpanzee EPI-1) are identical to the cloned putative human epididymal protein HE1. Screening of a chimpanzee epididymal cDNA library enabled isolation of a cDNA clone of chimpanzee EPI-1. On the cDNA level, chimpanzee EPI-1 and human HE1 are 99% identical. Northern analysis localized chimpanzee EPI-1 mRNA to the distal caput epididymidis. With EPI-1 primers, polymerase chain reaction of reverse-transcribed rhesus monkey (Macaca mulatta) epididymal RNA enabled isolation of a rhesus monkey EPI-1 cDNA clone. The derived amino acid sequence of rhesus monkey EPI-1 is identical to chimpanzee EPI-1 and to human HE1. Northern analysis localized rhesus monkey EPI-1 mRNA to the distal caput and the proximal corpus epididymidis. Northern analysis also showed that chimpanzee EPI-1 and rhesus monkey EPI-1 gene products are expressed specifically in the epididymis and not in any other tissue examined.

Cloning of complementary DNA encoding a 135-kilodalton protein secreted from porcine corpus epididymis and its identification as an epididymis-specific alpha-mannosidase.

In the preceding study (Okamura et al., 1992; Biol Reprod 47:1040-1052) we suggested that a 135-kDa protein secreted by porcine epididymis is involved in the sperm maturation. In this work, we have isolated the cDNA clone coding the 135-kDa protein in an effort to investigate its structure and function. The 135-kDa protein was purified from porcine cauda epididymal fluid. Three oligonucleotide probes were synthesized according to the amino acid sequences of N-termini of the native protein and trypsin-digested peptides. A cDNA clone hybridizing with these three probes was isolated from the cDNA library derived from the porcine proximal corpus epididymis. It encodes a novel protein with 1,006 amino acid residues in an open reading frame. Its overall amino acid sequence was significantly homologous (25.7%) to the alpha-mannosidase precursor of Dictiostelium discoideum (P34098). The 135-kDa protein could digest both p-nitro-phenyl-alpha-D-mannoside and high mannose oligo saccharide (Man8-GlcNAc2), strongly suggesting that it is an alpha-mannosidase homologue. The expression of this protein was specific to porcine and was localized to the very narrow parts of epididymis: the border of the caput and corpus epididymis. This protein may serve as a good marker for the functional differentiation in porcine epididymis. A possible role of this protein in the species-specific sperm-egg interaction is discussed.

Electrical slow wave activity of the cat stomach: its frequency gradient and the effect of indomethacin

The present study was performed to establish the intrinsic frequency of the slow waves in different regions of the cat stomach, to define the propagation velocity of the slow wave along the stomach, and to determine whether endogenous prostaglandins can affect the slow wave frequency. In 20 cats, electrical activity was recorded from the anterior wall of the intact stomach in vivo and in vitro, and in vitro after cutting the stomach into 16 pieces to isolate each pair of electrodes. In vivo, slow waves (4.1 +/- 0.5 cpm) were seen only from mid corpus to pylorus, the apparent propagation velocity decreasing towards the antrum. In vitro: (a) after cutting, the slow wave frequency increased, to a maximum in 1 h (12 +/- 1.8 cpm; range 10.2-17.3), with the highest frequency always in the mid or orad corpus, usually on the greater curvature (GC), (b) with indomethacin (10(-5) M) the increase in slow wave frequency was prevented or reversed, and there was a frequency gradient with the highest frequency (4.4 +/- 1.2 cpm) uniformly located in the most proximal active site on the GC, and (c) slow waves on the GC were more stable, regular and continuous than on the lesser curvature (LC), the difference being most evident in the corpus. The results suggest that the cat stomach behaves as a system of electrically coupled oscillators of different frequencies. The dominant oscillator of highest frequency is situated in the proximal corpus of the GC, with the remainder of the distal stomach entrained at this frequency. All gastric slow wave oscillators can be driven to higher frequencies by endogenous prostaglandins. The decreasing velocity of slow wave propagation distally suggests that oscillator properties and/or coupling among oscillators differs in the cat.

Sequential penile ultrasound monitoring of patients treated with chronic intracavernous prostaglandin e 1

Objectives Clinical outcome studies of prostaglandin E 1 (PGE 1) have shown a markedly decreased rate of palpable fibrosis and plaque formation. In this prospective study we investigate the potential of this agent to produce subclinical fibrotic changes. Methods Real-time high-resolution ultrasound scanning of the corpora was performed using a 7.5 to 10 MHz linear array transducer in 80 men on initiation of treatment with self-administered PGE 1 and at quarterly intervals during the course of follow-up (3 to 28 months). The dorsal portion of the penile shaft was scanned in the transverse and sagittal planes from base to glans for a side by side comparison of the cavernosal tissue, evaluating local abnormalities of tissue echogenicity. Results Palpable lesions were not detected in any men on quarterly follow-up examination. Thirteen (16.5%) men developed new echogenic foci not present on pretreatment scanning at the following locations: proximal corpus cavernosum, subcutaneous tissues, and corpus spongiosum. These changes were observed both as single and multiple lesions ranging in size from 1 to 10 mm. The presence of these findings was independent of the etiology of impotence, dose frequency, and duration of intracavernous therapy. Conclusions The significance of these subclinical changes is unknown but their low incidence should be recognized when considering long-term intracavernous therapy.

Detection of 25-kDa Anti-Agglutinin in Epididymal Plasma and Spermatozoa Collected from Various Regions of Boar Epididymis.

Distribution of the 25-kDa epididymal anti-agglutinin for spermatozoa was examined by the Western blotting technique in fluid collected from boar rete testes and epididymides. Fluid was collected from the rete testes and various regions of the epididymis, and then plasma and sperm extracts were prepared. Antiserum was raised against the anti-agglutinin, and specific antibody was purified from it. In the plasma, a reaction between the anti-agglutinin and purified antibody was first observed in the proximal corpus epididymidis and became stronger in the more distal regions. In extracts from washed spermatozoa using the original sample buffer, anti-agglutinin was detected between the proximal corpus and the distal cauda and more strongly in the distal corpus. A thorough washing of spermatozoa on a discontinuous Percoll gradient brought about only minor changes in the detection pattern of anti-agglutinin. However, in samples extracted from washed spermatozoa using a modified sample buffer containing twofold detergent and twofold 2-mercaptoethanol, a stronger reaction was observed between the anti-agglutinin and purified antibody in the distal cauda than in the distal corpus. These results indicate that free or loosely sperm-bound anti-agglutinin increases in the corpus and cauda epididymides. It is also suggested that solubility of the anti-agglutinin associated with spermatozoa in the original sample buffer decreases in the cauda epididymidis.

Electron microscopic immunolocalization of the 18 and 29 kilodalton secretory proteins in the mouse epididymis: evidence for differential uptake by clear cells.

In previous studies we reported the synthesis, secretion, and immunolocalization at the light microscopic level of two mouse epididymal proteins, MEP 7 and MEP 10 [Rankin et al. (1992b), Biol. Reprod., 46:747-766]. MEP 7 is the mouse homologue of the rat metalloproteins, AEG/D and E, and MEP 10 is the mouse homologue of the rat retinoic acid binding proteins, B and C. We now describe the immunolocalization of MEP 7 and MEP 10 in the mouse epididymis at the electron microscopic level. MEP 7 was localized in the Golgi apparatus, in small electron-lucent secretory vesicles, and on microvilli of the principal cells from the distal caput epididymidis to the cauda. The luminal contents were also immunoreactive in these regions of the epididymis. Although some gold particles were associated with the sperm surface, there was no selective concentration of these particles. In addition, MEP 7 was localized in large (600 nm) supranuclear endocytic vesicles and in infranuclear lysosomes. MEP 10 immunoreactivity was also seen on the microvilli of the principal cells of the distal caput and corpus and the luminal contents from the distal caput to the cauda epididymidis. There was no association of gold particles with the sperm surface. In contrast to MEP 7, there was no detectable MEP 10 immunoreactivity on the organelles of the principal cells involved in protein secretion or endocytosis. Clear cells also demonstrated immunoreactivity to MEP 7 and MEP 10. However, the intensity of immunolabeling, and the number of clear cells labeled, was greater with MEP 10 than MEP 7. In the case of MEP 7, the gold particles were located on the large supranuclear endocytic vesicles and on some infranuclear lysosomes, from the proximal corpus to the middle cauda, while in the case of MEP 10, gold particles were predominantly present in infranuclear lysosomes from the distal caput to the middle cauda. These results suggest that the principal cells are involved in both the secretion and endocytosis of MEP 7. The MEP 10 and MEP 7 proteins present in the lumen of the mouse epididymis are endocytosed from the lumen and degraded in the clear cells. However, the process of endocytosis by the clear cells of these two proteins appears to be different.

Ultrastructure and motility of spermatozoa in the male reproductive tract of perameloid marsupials.

The number, distribution, maturation, motility and ultrastructure of spermatozoa from both northern (Isoodon macrourus) and southern (Isoodon obesulus) brown bandicoots were examined. One epididymidis per animal was fixed for light microscopy and transmission electron microscopy, and the contralateral side was used for the determination of sperm number, distribution and motility. Sperm form was similar between the two species. Approximately 56 x 10(6) testicular sperm and 100 x 10(6) epididymal sperm per side were present in I. macrourus, about 60% of which were in the caudal region. Initiation of sperm nuclear rotation and loss of the cytoplasmic droplet was first observed in distal caput or proximal corpus segments along with slow progressive motility. In these sperm, dislocation and anterior movement of the sperm neck from the implantation fossa and the modification of the distal margins of the sperm acrosome were evident. Motility of cauda epididymidal spermatozoa was rapid and coordinated, movement was restricted to one plane, and lateral head displacement was marked. As media viscosity increased, sperm velocity decreased, as did the amplitude of the tail beat, its frequency, and lateral head displacement but, in viscous mineral oil and mixtures of media and prostatic exudate, extremely rapid sinusoidal motility occurred. This study has detailed unusual morphological changes in bandicoot sperm during epididymal maturation and has shown that, although bandicoot sperm differ morphologically from those of the dasyurids, particularly in relation to head-tail orientation and tail ultrastructure, they exhibit similar motility.

Regional variation of specific gene expression in the dog epididymis as revealed by in‐situ transcript hybridization

In-situ transcript hybridization was used to characterize the regional distribution of three marker gene transcripts which are expressed abundantly in the canine epididymis. The gene products CE1, CE4 and CE5, which are the canine equivalents of the human homologues HE1, HE4 and HE5, are shown to be expressed in a tissue-specific and regionally characteristic pattern in the epididymal epithelium. CE1 mRNA was expressed very weakly in the efferent ducts but was expressed at a high level throughout the caput and corpus regions of the epididymis, decreasing somewhat in the distal cauda region. CE4 mRNA was not detectable in the efferent ducts and was only expressed moderately in the remainder of the epididymis, with greatest levels in the caput and proximal cauda regions, and decreasing in the distal cauda. CE5 mRNA showed the most marked regional variation in levels with little or no mRNA detectable in the caput and proximal corpus regions, but increasing dramatically in the distal corpus and cauda. In the transition region of the central corpus, the CE5 mRNA appeared to be expressed intermittently, giving a mottled signal appearance over the epididymal epithelium. The patterns of mRNA distribution for the three marker genes in the dog epididymis were, therefore, essentially similar to those for the equivalent human homologues, providing further support for the suitability of the dog epididymis as a model for the human.

Development of sperm motility patterns in the murine epididymis

The maturation of sperm motility in the epididymis of the mouse was assessed using a computer-assisted sperm analysis system. Spermatozoa were immotile in the most proximal regions of the epididymis but developed motility rapidly in the proximal caput epididymis; the percentage motility remained high thereafter. In the caput, flagellar beat was erratic with little progression, but in the proximal corpus region circular movement patterns were reflected in reduced linearity (LIN) and straightness (STR) of the sperm tracks, although velocities were little changed and wobble (WOB) increased. In the mid-corpus region, however, all velocities, LIN, STR and WOB, increased markedly. In more distal regions there was little change in these parameters. Distribution curves of the kinematic parameters of spermatozoa obtained from each region indicated that the most heterogeneous population was that from the mid-corpus epididymis; the most homogeneous was that from the mid-cauda region. Individual sperm tracks revealed slowly progressing spermatozoa in the distal caput, transforming to motion in small circles, interrupted by more linear progression. More distally, linear progression was interrupted by looping movements and a generally progressive path was observed thereafter, with less deviation from the average path as the spermatozoa matured. Spermatozoa displaying motion compatible with passing the uterotubal junction were first found in the proximal corpus epididymis, in agreement with earlier in-vivo fertilization studies on where fertilizing capacity is achieved with epididymal spermatozoa.

Molecular cloning and characterization of a novel human sperm antigen (HE2) specifically expressed in the proximal epididymis.

A novel human cDNA encoding a small secretory glycopeptide specifically expressed within the caput and proximal corpus regions of the human epididymis, HE2, has been cloned and sequenced. Southern hybridization analysis showed it to be derived from a single-copy gene. A subclone containing the coding region of the mature peptide was used to generate the putatively encoded peptide as a 10,000 M(r) recombinant fusion protein in a bacterial expression system. This recombinant HE2 protein, as well as an oligopeptide deduced from the open-reading frame, was used to raise polyclonal antisera. Immunohistochemistry and immunofluorescence showed that the predicted HE2 peptide is present in the epididymal epithelium and on the sperm surface, where it adopts a typical antigenic pattern with a subacrosomal equatorial distribution on the sperm head.

Chromatin condensation in hamster sperm: A flow cytometric investigation

In this study we have used acridine orange staining, as described by Evenson (1990), to follow changes in DNA packaging as they occur in hamster spermatozoa which have left the testis and are undergoing maturation in the epididymis. Measurement of the green and red fluorescent intensities of hamster sperm nuclei by flow cytometry demonstrated a decrease in acridine orange binding to DNA as sperm made their way from proximal corpus epididymis to the vas deferens. Using sperm from the cauda epididymis of the mature hamster as the standard, a method was developed for estimating the % of cells in a given sample that have matured with regard to DNA packaging. Staining with bromobimane was used to determine the extent of sulfhydryl oxidation in the nuclei. It was seen that sulfhydryl oxidation occurred mainly in the cauda epididymis whereas another process in chromatin condensation occurred earlier, during sperm passage through the caput epididymis. This earlier process could be mimicked by incubating sperm nuclei with alkaline phosphatase, suggesting that it consists of removal of phosphate in protamine.

Lipids and calcium uptake of sperm in relation to cold shock and preservation: a review

When sperm of the ram, bull, boar and stallion are cold-shocked by rapid cooling to near freezing point, motility and metabolic activity are irreversibly depressed and the acrosome and plasma membrane disrupted. Ram sperm become susceptible to cold shock in the proximal corpus region of the epididymis when the cytoplasmic droplet has moved backwards to the distal portion of the sperm midpiece. The membrane constituents phospholipids and cholesterol are important in cold shock which causes loss of lipid from sperm. The susceptibility of sperm to cold shock is linked with a high ratio of unsaturated:saturated fatty acids in the phospholipids and a low cholesterol content. The high unsaturated fatty acid content of sperm also makes them susceptible to damage from peroxidation which adversely affects motility, metabolism, ultrastructure and fertility. Hydroxynonenal, a product of fatty acid peroxidation, depresses the motility and oxygen uptake of ram sperm in vitro and may react with the -SH groups of the axonemal microtubules. High calcium concentrations in the external medium may decrease the motility and metabolism of sperm and 'calcium intoxication' may be a factor in cold shock. Lowering the environmental temperature increases calcium uptake by sperm and the effect is aggravated if the rate of cooling is rapid. Phospholipids, particularly those in egg yolk, protect sperm to some extent from cold shock and also prevent increased calcium flux into the sperm. Suggestions are made for increasing the life span of sperm during preservation and microencapsulation by adding agents that may stabilize membranes, counter peroxidation and decrease calcium uptake.

Region-specific variation of gene expression in the human epididymis as revealed by in situ hybridization with tissue-specific cDNAs.

Three tissue-specific gene probes that had been isolated by differential screening from a human epididymal cDNA library--HE1, HE2, and HE5--were employed to investigate regional specializations in the human epididymis. All 3 cDNAs were derived from major transcripts of the epithelial cells lining the epididymal duct. Each mRNA species, however, exhibited a discrete longitudinal pattern of hybridization with maxima in different regions of this organ, suggesting regional specializations of gene expression. The HE5 mRNA, which was recently shown to encode the peptide backbone of the human leukocyte differentiation antigen CDw52, showed maximum levels in the distal corpus epididymidis and in the vas deferens, whereas the HE2 mRNA was found predominantly in the caput and proximal corpus sections of the epididymis. HE1 mRNA was found in high amounts in all parts of the epididymis, displaying a 2-peak expression pattern with maxima in the distal caput and distal corpus of the epididymal duct.