Gamma Radiation Induced Changes in Primary Oocyte and Zona Pellucida

Abstract

Objective: This study was performed to analyze the morphological changes in primary oocyte
and zona pellucida of primary follicle in prepubertal albino rats of three weeks age after exposure
to gamma radiation.
Material and Methods: 72 female albino rats of age of three weeks were used. Out of these 24,
received 4.5 Gray, another 24 received 8.3 Gray of Gamma radiation, and the rest of them
received sham radiation. Ovaries of rats were dissected after one day, 7 days and 14 days after
irradiation. Five random histological sections of each ovary were examined.
Results: Intense necrosis was evident in oocyte and granulosa cells of primary follicles after one
day- post radiation. The zona pellucida remained in contact with the oocyte and granulosa cells in
initial phase of atresia. With progressing atresia, zona pellucida lost its contact with the oocytes
and granulosa cells. Disintegration of zona pellucida started after development of apoptotic
bodies in primary follicles. Disintegrated zona pellucida disappeared rapidly in experimental
groups, particularly in high dose group. The basement membrane was irregular and disrupted in
atretic follicles.
Conclusion: Therefore, we can conclude that gamma radiation induces rapid necrosis and cyst
formation in primary oocyte. Disintegration of zona pellucida with progression of atresia in ovarian
follicle was evident. Gamma radiation also produces irregular, disrupted and thinner basement
membrane