ISSN:
0002-9106
Schlagwort(e):
Life and Medical Sciences
;
Cell & Developmental Biology
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Medizin
Notizen:
Normal guinea pig oocytes develop in an environment of AMPase within the granulosa cells of the wall, the cumulus and the latter's projections that traverse the zona pellucida to terminate at the surface of the oocyte. Oocytes in developing non-vesicular and small vesicular follicles have an ATPase activity at their surface, which appears to indicate specialized absorptive mechanisms confined to these early stages of development. Acid phosphatase, present in granules scattered throughout the cytoplasm of all developing oocytes, may be evidence of a mechanism in this species, whereby the oocyte hydrolyzes unidentified nutritional reserves.Histologically normal appearing oocytes in atretic vesicular follicles may show deviations from the normal histochemical pattern, i.e., clumping and subsequent loss of acid phosphatase activity or a band of AMPase activity at the periphery of the oocyte representing apparent enlargement of the terminals of projections of the cumulus. These deviations may reflect disturbances of granulosa cell-oocyte transfer as a consequence of beginning atetric processes in the follicle wall. By the eighth day of the estrous cycle the granulosa layer of many medium sized follicles has been invaded by a few long strands of nucleoside polyphosphatase positive thecal connective tissue often carrying a small blood vessel. This early stage of atresia is apparently followed by shedding of the granulosa layer and hypertrophy of the thecal layer which begins the transformation of atretic follicles into interstitial masses.
Zusätzliches Material:
1 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/aja.1001190207
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