Re-examination of spermatogonial renewal in the rat by means of seminiferous tubules mounted "in toto".
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Animals↗
Biomedical subjects
E Bustos-Obregon
Publications and source records attributed to E Bustos-Obregon.
Identification of androgen binding-protein (ABP) from testis and epididymis of the seasonal rodent, Octodon degus (Molina, 1872).
ABP, a Sertoli cell secretory product, was identified in the seasonal rodent Octodon degus (Molina, 1872). It was shown to be present in cytosols from the testis and epididymis. It migrated with an Rf of 0.37 on nondenaturing polyacrylamide gels. Ligation of the vas efferens caused the disappearance of ABP from the epididymis and its accumulation in the testis, indicating its testicular origin. Binding to [3H]5 alpha-DHT was specific and completely reversible, with an apparent Kd of 3.5 +/- 0.4 X 10(-9) M. Half-times of association and dissociation were at 15 and 120 minutes, respectively. Binding equilibrium was achieved at 120 minutes. Steroid affinity relative to the best competitor, 5 alpha-DHT, was 0.27 for testosterone, 0.06 for 17 beta-estradiol, and 0.01 for cyproterone acetate. The presence and similar characteristics of ABP in a wide variety of mammals, including those with special reproductive strategies such as seasonal breeding, suggests that this protein may play a general role in the mechanisms regulating spermatogenesis, probably affecting the transport and concentration of androgens in the testis and epididymis.
3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
Human sperm penetration into zona-free hamster oocytes as a test to evaluate the sperm fertilizing ability.
Human sperm entry into zona-free hamster oocytes was used to test the fertile ability of spermatozoa from semen samples of men attending an Infertility Clinic. Sperm chromatin dispersion as seen under the phase-contrast microscope, was used as criterion for sperm entry. The ultrastructural study showed that the behaviour of the gamete membranes during fusion did not basically differ from that of normal fertilization. Eighty four samples were classed as normal (according to the spermiogram) but only 62 (74%) gave a positive test, as compared to only 30 (32%) positive test of 95 samples with abnormal spermiograms. Eight hundred and ten oocytes inseminated with spermatozoa from normal samples gave a 25% penetration, while 1046 oocytes inseminated with spermatozoa from abnormal samples gave a 7% penetration. The normality of hamster oocytes was demonstrated by contemporary insemination with human and hamster spermatozoa. While the percentages of human sperm penetration remained low, hamster sperm penetration was over 70%. The present bioassay is recommended as an additional parameter to the spermiograms for the study of male fertility.
Animals↗
Sperm immobilization by dental focus microorganisms.
Focal infections and their ability to produce alterations in different tissues have been in dispute for long time. The purpose of this work was to observe "in vitro" the effect of an Escherichia coli filtrate obtained from open pulpar necrosis on human sperm motility. It was observed that the E. coli filtrate produced a loss in sperm motility. The immobilizating factor was studied and characterized as a heat-stable, resistant to lyophilization and non-dializable substance, which could via blood stream reach the male reproductive system and affect sperm motility.
Dental Pulp Necrosis↗
Chromatin packing in normal and teratozoospermic human ejaculated spermatozoa.
Normal shaped (oval) and teratozoospermic spermatozoa have been compared by several techniques, including the use of "in vitro" S-S agents, cytofluorometry determination of DNA, total proteins, and ultracytochemical analysis of the presence and localization of SH proteins present in human sperm nuclei. A close relationship between S-S stability and chromatin packing is inferred from the differential sensitivity to S-S reduction agents exhibited by normal sperm nuclei which shows a lower Feulgen reactivity and special distribution of SH proteins compared to teratozoospermic cells. Both, S-S stability and chromatin packing are higher in normal sperms.
Cell Nucleus↗
Alkylating agents and mouse spermatogenesis: effects of a single dose of cyclophosphamide.
Cyclophosphamide (CFA) is one of the alkylating agents which has now been used with some success in the treatment of human neoplasias and renal disease. To evaluate how this drug could affect the seminiferous epithelium, a single dose of CFA (200 mg/kg/weight) was given to twenty adult mice (strain A/SW). The effect of the drug was compared with a control group to which physiological saline solution was injected. Mice were sacrificed by cervical dislocation at four different time intervals after the drug administration in order to evaluate the action of the drug in different stages of spermatogenesis. The effect of the drug was appreciated as soon as four days after its administration. The initial damage to the epithelium was characterized by vacuolization of the Sertoli cells. Of all germ cells, primary spermatocytes showed the highest sensitivity to the drug. A high percent of teratozoospermia in the experimental group, when compared to the control group, was observed at all time intervals. The way CFA affects the morphology of mammalian spermatozoa and the usefulness of the animal model presented are discussed.
Alkylation↗
An "in vitro" system for the study of rat spermatogonial proliferative control.
The effect of a "testicular extract" on spermatogonial proliferation in adult rats is comparatively studied both "in vivo" and "in vitro". Both in irradiated rats injected with "testicular extract" as in testicular fragments from irradiated rats incubated in culture medium, addition of "testicular extract" elicits an inhibition in thymidine-H3 uptake by type A spermatogonia. This is not the case for non irradiated rats or incubation of testicular samples from non irradiated animals after addition of "testicular extract". The "in vitro" system for assay of the spermatogonial chalone is used to analyze the general characteristics of this mitotic inhibitor.
Animals↗