Nucleic Acid Labelling of Experimentally-Induced Cryptorchid Rat Testis

Hollinger, Mannfred A.; Davis, Joseph R.

doi:10.1530/jrf.0.0180325

Cited by 6 publications

(2 citation statements)

References 15 publications

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“…The fundamental biochemical alterations contributing to degenerative changes in the germinal epithelium accompanying cryptorchidism have not been elucidated. Elevation of the rates of protein and nucleic acid labelling (Davis, Morris & Hollinger, 1964;Davis & Firlit, 1965; Hollinger & Davis, 1969) probably represents an 'unmasking' of the normal activity of the surviving cells, and requires several weeks for complete development. In contrast, the present studies indicate that inositol synthesis is greatly impaired within 3D ownloaded from Bioscientifica.com at 10/25/2020 05:51:57PM…”

Section: Discussionmentioning

confidence: 99%

Biosynthesis of Myo-Inositol by Rat Testis Following Surgically Induced Cryptorchidism or Treatment With Triethylenemelamine

Morris¹,

Collins²

1971

Reproduction

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The biosynthesis of inositol from d-glucose was measured in testis slices from normal, cryptorchid and triethylenemelamine (TEM)-treated rats. A significant reduction of inositol synthetic activity accompanied the disappearance of spermatids and spermatozoa in both cryptorchid and TEM-treated animals. The onset of reduced inositol synthetic activity was extremely rapid in the cryptorchid testis, and preceded the appearance of grossly demonstrable histological alterations. These data suggest that de novo inositol synthesis might be required for maintenance of the cellular integrity of the germinal epithelium. This hypothesis is discussed in conjunction with recent theories concerning the r\l=o^\leof inositol in the uptake of protein and nucleic acid precursors.

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Section: Discussionmentioning

confidence: 99%

Biosynthesis of Myo-Inositol by Rat Testis Following Surgically Induced Cryptorchidism or Treatment With Triethylenemelamine

Morris¹,

Collins²

1971

Reproduction

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“…Previous workers have noted that the incorporation of thymidine varies with the physiological state of the testis (Hollinger & Davis, 1969;Wiest & Wrba, 1970;Go et al, 1971) ; the results appear to depend on the number of cells synthesizing DNA. The present experiments suggest that gonado¬ trophins control the DNA synthetic activity of the individual germ cells, but it is not known whether the gonadotrophins affect the germ cells directly or whether they have primary actions on the Leydig and supporting cells.…”

Section: R Ortavant Et Almentioning

confidence: 91%

Gonadotrophic Control of Tritiated Thymidine Incorporation in the Germinal Cells of the Rat Testis

Ortavant¹,

Courot²,

Reviers³

1972

Reproduction

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The gonadotrophic control of spermatogenesis varies with age. Thus, ovine fsh stimulates spermatogenesis in the hypophysectomized prepubertal rat more effectively than ovine lh whereas the opposite is found in the adult (Ortavant, Courot & de Reviers, 1969;Courot, Ortavant & de Reviers, 1971). Gonadotrophic hormones reduce the proportion of germinal cells which undergo degeneration. It was thought probable that this effect was the result of actions of these hormones on the metabolism of germinal cells. We have started to investigate this problem by studying the effects of fsh and lh on the synthesis of DNA by spermatogonia and primary spermatocytes in the rat. It has previously been shown that hypophysectomy reduces the intensity of [3H]thymidine-labelling of the DNA in these cells (R. Ortavant, unpublished data).Six prepubertal and six adult Wistar rats were hypophysectomized and then treated subcutaneously with highly purified ovine fsh or lh: the adult rats received three injections, each containing 100 µg fsh-cnrs-de 58 (xl-5 nih fsh-s1) or 100^g lh-gnrs-m2 (x 1-4 nih lh-s1), at 12-hourly intervals starting 30 days after hypophysectomy; the prepubertal rats received 15^g fsh-cnrs-m1 ( x4 nih fsh-s1) or 20 µg lh cnrs-m1 ( 1-5 nih lh-s1) twice daily for 12 days, starting immediately after hypophysectomy on the 27th day after birth. Previous experiments using these treatment schedules had demonstrated an effect of fsh on spermatogenesis in prepubertal rats and of lh in adults. All the rats were killed 12 hr after the last injection of hormone, 1 hr after intraperitoneal administration of [3H]thymidine (IT /iCi/g body weight, specific activity: 10 Ci/mmol).The testes were fixed in Bouin-Hollande solution and autoradiographs of 5-µ paraffin-wax sections were prepared with Ilford K5 emulsion. Photo¬ metric grain density measurements were made over type A3 and A4 spermatogonia (Clermont & Bustos-Obregon, 1968) at stages 3 and 4 of the cycle of the seminiferous epithelium and over preleptotene and leptotene primary spermatocytes at stages 8 and 1 (Roosen-Runge & Giesel, 1950). The grain density was measured over sixty nuclei of each type of cell in each animal and the median intensities of labelling were compared by the method of Lazar & Gerard-Marchant (1965) after subtraction of the background level. 451

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In vitro synthesis of RNA by Xenopus spermatogenic cells. I. Evidence for polyadenylated and non‐polyadenylated RNA synthesis in different cell populations

Kalt

1979

J. Exp. Zool.

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Premeiotic and postmeiotic (haploid) gene expression during spermatogenesis in the anuran, Xenopus laevis, was studied by analyzing the accumulation of radioactively labelled cytoplasmic polyadenylated [poly (A +)] and non-polyadenylated [poly (A -)] RNAs. Dissociated spermatogenic cells were labelled and maintained in an in vitro system capable of supporting cell differentiation. Labelled cells were separated by density gradient centrifugation into subpopulations enriched for individual spermatogenic stages. RNA was extracted and purified from each cell fraction, and separated into poly (A +) and poly (A -) species. Comparison of poly (A +) to non-poly (A) radioactivity in cells labelled with tritiated uridine or adenosine demonstrated that (1) all cell fractions produced significant quantities of polyadenylated RNA relative to total RNA synthesis; and (2) that a cell fraction enriched for pachytene spermatocyte RNA contained up to 15% of total cytoplasmic and 35% of total polysomal RNA labelled as poly (A +) containing species. RNA was also characterized by sucrose density gradient centrifugation and polyacrylamide gel electrophoresis. All cell types showed typical poly (A -) peaks of 4S, 18S and 28S, corresponding to tRNA (4S) and rRNAs (18, 28S) respectively. Spermatids and spermatozoa had additional absorbance peaks at 13 and 21S which cosedimented with Xenopus oocyte mitochondrial rRNA. Patterns of incorporation of uridine and adenosine into poly (A +) RNA in all germ cell fractions tested were complex. In all cases, major areas of radioactivity were found in a broad band sedimenting between 6-17S. Spermatid fractions showed a prominent peak of incorporation at 6-8S, while pachytene cells also showed heavier poly (A +) peaks in the 17-25S region. A non-polyadenylated RNA species sedimenting at 6-8S with a relatively rapid rate of turnover was also observed in spermatids. From these results it is concluded that synthesis of transfer, ribosomal, and putative messenger RNA species continues in spermatogenic cells throughout all but the very last stages of spermatogenesis in Xenopus.

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Nucleic Acid Labelling of Experimentally-Induced Cryptorchid Rat Testis

Cited by 6 publications

References 15 publications

Biosynthesis of Myo-Inositol by Rat Testis Following Surgically Induced Cryptorchidism or Treatment With Triethylenemelamine

Biosynthesis of Myo-Inositol by Rat Testis Following Surgically Induced Cryptorchidism or Treatment With Triethylenemelamine

Gonadotrophic Control of Tritiated Thymidine Incorporation in the Germinal Cells of the Rat Testis

In vitro synthesis of RNA by Xenopus spermatogenic cells. I. Evidence for polyadenylated and non‐polyadenylated RNA synthesis in different cell populations

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