Temperature Effect on the Permeability of Plasma Membranes of Advanced Germinal Cells of the Rat Testis

Advanced germinal cells (spermatocytes and spermatids) prepared from adult rat testes, but not other cells, released their cellular contents into the incubation medium when they were incubated at 37° at a physiological pH. Evidence was presented that the release of cellular contents was due to changes in the permeability of the plasma membranes of these cells. The hypothesis is advanced that the changes in the permeability of the plasma membranes of the advanced testicular germinal cells of the rat may be intimately associated with the cellular degeneration and cessation of spermatogenesis which occur in cryptorchid testes.

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Differential expression of divalent metal transporter DMT1 (Slc11a2) in the spermatogenic epithelium of the developing and adult rat testis

AJP Cell Physiology ◽

10.1152/ajpcell.00061.2004 ◽

2005 ◽

Vol 288 (1) ◽

pp. C176-C184 ◽

Cited By ~ 17

Author(s):

Kathleen P. Griffin ◽

Donald T. Ward ◽

Wei Liu ◽

Gavin Stewart ◽

Ian D. Morris ◽

...

Keyword(s):

Germ Cells ◽

Male Fertility ◽

Plasma Membranes ◽

Iron Homeostasis ◽

Divalent Metal ◽

Intracellular Iron ◽

Divalent Metal Transporter ◽

Rat Testis ◽

Metal Transporter ◽

Adult Rat

Iron is essential for male fertility, and disruptions in iron balance lead to impairment of testicular function. The divalent metal transporter DMT1 is a key modulator of transferrin- and non-transferrin-bound iron homeostasis. As a first step in determining the role of DMT1 in the testis, we have characterized the pattern of DMT1 expression in the developing and adult rat testis. Northern blot analysis and RT-PCR of testis polyadenylated RNA revealed the presence of iron-responsive element (IRE) and non-IRE transcripts. Semiquantitative immunoblotting of immature and adult rat testis uncovered the expression of two distinct DMT1 protein species. Immunohistochemistry showed that DMT1 was widespread throughout each seminiferous tubule and was expressed in the intracellular compartment. In the adult rat testis, DMT1 was immunolocalized to both the Sertoli and germ cells. In contrast to the immature testis, expression was dependent on the stage of the spermatogenic cycle. DMT1 was not detected on any plasma membranes in either the developing or the adult testis, suggesting that DMT1 is not primarily responsible for translocating iron across this epithelium. Our data suggest an important role for DMT1 in intracellular iron handling during spermatogenesis and imply that germ cells have a need for a precisely targeted and timed supply of iron. We suggest that DMT1 may, as it does in other tissues, play a role in transporting iron between intracellular compartments and thus may play an important role in male fertility.

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Enrichment of sulfogalactosylalkylacylglycerol in a plasma membrane fraction from adult rat testis

Canadian Journal of Biochemistry ◽

10.1139/o80-164 ◽

1980 ◽

Vol 58 (10) ◽

pp. 1230-1239 ◽

Cited By ~ 17

Author(s):

Margaret A. Shirley ◽

Harry Schachter

Keyword(s):

Plasma Membrane ◽

Membrane Fraction ◽

Plasma Membranes ◽

Gradient Centrifugation ◽

Membrane Material ◽

Radioactive Label ◽

Rat Testis ◽

Plasma Membrane Fraction ◽

Adult Rat ◽

Dna And Rna

Adult rat testis homogenates were fractionated by differential centrifugation followed by two discontinuous gradient centrifugation steps under identical conditions except for the absence of digitonin in the first gradient and the presence of 0.03% digitonin in the second gradient. The first gradient centrifugation yielded a membrane fraction enriched 28.8-fold in 5′-nucleotidase, 21.5-fold in UDP-Gal:GlcNAc galactosyltransferase and 18.6-fold in UDP-GlcNAc:α-D-mannoside N-acetylglucosaminyltransferase. Repeat centrifugation of this membrane fraction in the presence of digitonin resulted in the sedimentation of most of the membrane material to a denser level of the gradient; this material was enriched 32.1-fold in 5′-nucleotidase but only 1.9-fold in galactosyltransferase and 8.4-fold in N-acetylglucosaminyltransferase. The plasma membrane fraction was shown to be free of glucose-6-phosphatase, succinate dehydrogenase, β-N-acetylglucosaminidase, DNA, and RNA. The fraction therefore appears to be enriched in plasma membrane but relatively free of Golgi membrane contamination, as indicated by the relatively low levels of glycosyltransferases, and of contamination by other organelles. The testicular cells which contribute plasma membrane to this fraction have not yet been definitively identified; the contribution by Sertoli cells is particularly difficult to assess since these cells have been reported to be enriched in 5′-nucleotidase. However, sulfogalactosylalkylacylglycerol (SGG), a lipid previously shown to be present primarily in primary spermatocytes, spermatids, and spermatozoa, was enriched 33.1-fold in the plasma membrane fraction; this finding as well as experiments with [36S]sulfate-labeled sulfogalactosylalkylacylglycerol at various times after injection of radioactive label have indicated that both spermatocytes and spermatids were contributing SGG-rich membrane material to our plasma membrane preparation. This membrane material is most probably derived from the plasma membranes of the spermatocytes and spermatids.

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