COMPARISON OF CA2+ RESPONSES IN HUMAN OOCYTES FERTILIZED BY SUBZONAL INSEMINATION AND BY INTRACYTOPLASMIC SPERM INJECTION

• Type: Article in International Scientific Journal
• Date: 1994

Authors

TESARIK, J (Author) Other; sousa, m (Author) ICBAS

Journal

Title: Fertility and Sterility

Vol. 62

Pages: 1197-1204

ISSN: 0015-0282

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 66 Citations

Scopus - 66 Citations

Other information

Authenticus ID: P-001-J7S

Abstract (EN): Objective: To evaluate the consequences of bypassing the normal interaction between the sperm and oocyte surfaces for the form of Ca2+ responses developing in oocytes at fertilization. Design: Oocytes were fertilized by subzonal insemination (SUZI) (maintaining the normal interaction between cell surfaces of both gametes) or by direct intracytoplasmic sperm injection, and changes in intracellular free Ca2+ concentration were evaluated by confocal laser scanning microscopy after loading oocytes with a fluorescent Ca2+ indicator. Setting: Private hospital, public research center, and university-based laboratory. Patients, Participants: Patients participating in an assisted reproduction program. Interventions: In vitro fertilization, SUZI, intracytoplasmic sperm injection. Main Outcome Measures: Changes in intracellular free Ca2+ concentration. Results: All oocytes fertilized after SUZI showed an oscillatory Ca2+ response introduced by a short initial phase with faster Ca2+ oscillations. In contrast, oocytes fertilized after intracytoplasmic sperm injection did not show a similar change in the oscillation rhythm. In both cases, Ca2+ increases were propagated throughout the ooplasm in a wave-like manner. Conclusions: The results show that there is a relationship between gamete surface contact and the form of Ca2+ fluxes accompanying fertilization. When the contact between gamete surfaces is skipped by direct sperm injection to the ooplasm, a delayed, truncated Ca2+ response is produced which, however, can maintain the form of Ca2+ waves and Ca2+ oscillations typical of normal fertilization.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8