Related Experiment Video
Updated: Oct 7, 2026

Medium-throughput Screening Assays for Assessment of Effects on Ca2+-Signaling and Acrosome Reaction in Human Sperm
Published on: March 1, 2019
Sex differences in the extracellular Ca2+-independent release of LH and FSH
1Department of Physiology, University of Alberta, Edmonton, Canada.
Abstract:
The present study was undertaken to investigate the effects of sex and estrous cycle on the manifestation of the extracellular Ca2+-independent component of gonadotropin secretion. Quartered pituitaries from male, ovariectomized (OVX) females +/- estradiol (E2) implants, and mature females at each stage of the estrous cycle were perifused with Ca2+-free medium. Gonadotropin releasing hormone (GnRH)-stimulated luteinizing hormone (LH) and follicle stimulating hormone (FSH) secretion from male and OVX pituitaries was inhibited in Ca2+-free medium. In contrast, only a partial inhibition was obtained from OVX + E2 or regularly cycling female pituitaries. This extracellular Ca2+-independent component of gonadotropin secretion was lowest at estrus and increased progressively during the estrous cycle. Estradiol replacement in OVX animals resulted in a response similar to that obtained on proestrus. These results indicate that the extracellular Ca2+-independent component of LH and FSH release is only manifest from intact female and not male pituitaries, and is dependent on estradiol.
Related Concept Videos
X-Inactivation
The Y Chromosome Determines Maleness
Evolution
Around 300 million years ago, the two sex chromosomes diverged from two identical autosomal chromosomes. Over time, the Y chromosome has lost most of its genes, shrinking in size. Today,...
The Ratio of X Chromosome to Autosomes
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Dosage Compensation
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Development of the Sexual Organs in the Embryo and Fetus
Near the gonadal ridges, two duct systems are present: the mesonephric ducts (Wolffian ducts) and paramesonephric ducts (Müllerian ducts). These ducts form the basis for the male...

