Physiological factors influencing the human acrosome reaction

Date
1998
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Chapter one presents comprehensive background information regarding physiological conditions important during the acrosome reaction. Acrosomal exocytosis is possible only if spermatozoa have undergone membrane modifications in the course of capacitation. The physiological inducers have been identified as follicular steroids and glycoproteins of the zona pellucida. The molecular mechanisms have been partially characterized and involved several transduction pathways, i.e., tyrosine kinases and G proteins. Numerous tests were developed and used in order to assess the functional capability of human spermatozoa. Attention has now been shifted to assays measuring the fertilising ability of human spermatozoa. Evaluation of the vitally important sperm functions of capacitation, acrosome reaction, zona binding and zona penetration provide information which reflects the functional capability of spermatozoa. Assays that were discussed are: (i) computer-assisted semen analysis; (ii) acrosome reaction testing, and (iii) sperm-zona pellucida binding tests. Although sperm morphology cannot be classified as a sperm functional test for assessing fertilizing ability, it is the most important dynamic assessment of a semen analysis.
AFRIKAANSE OPSOMMING: Hoofstuk een omsluit 'n omvattende agtergrondstudie aangaande fisiologiese toestande wat belangrik tydens die akromosoomreaksie is. Die akrosoomreaksie vind slegs plaas indien spermatozoa membraanveranderinge tydens die kapasitasie-periode ondergaan. Die fisiologiese induseerders is geïdentifiseer as follikulêre steroïde en glikoproteïene van die zona pellucida. Die molekulêre meganismes is gedeeltelik identifiseerbaar en sluit verskeie beheermeganismes in, naamlik, tirosien kinases en G proteïene. Verskeie toetse toetse is al ontwikkel en gebruik om die funksionele toestand van menslike spermatozoa te bepaal. Die nuwer neiging is om die bevrugtingspotensiaal van die spermatozoa as maatstaf vir funksionele toestand te gebruik. Evluering van beangrike spermfunksies soos kapasitasie, akrosoomreaksie, zona binding en zona penetrasie verskaf waardevolle inligting ten opsigte van die funksionele toestand van spermatozoa. Toetse wat bespreek word, is: (i) rekenaar-berekende semenanalise; (ii) die akrosoomreaksie; en (iii) sperm-zona pellucida binding. Spermmorfologie kan egter nie beskou word as 'n sperm funksionele toets nie, maar is egter die mees dinamiese waardebepaler van 'n semenanalise.
Description
Thesis (MMed)--University of Stellenbosch, 1998.
Keywords
Spermatozoa -- Analysis, Semen -- Analysis, Acrosoma, Exocytosis
Citation