On the basis of the finding that capacitated (ready to fertilize) rabbit and human spermatozoa swim towards warmer temperatures by directing their movement along a temperature gradient, sperm thermotaxis has been proposed to be one of the processes guiding these spermatozoa to the fertilization site. Although the molecular mechanism underlying sperm thermotaxis is gradually being revealed, basi...

Fertility depends in part on the ability of the spermatozoon to respond to osmotic challenges by regulating its volume, which may rely on the movement of K+. These experiments were designed to characterize the K+ channels possibly involved in volume regulation of human ejaculated spermatozoa by simultaneously exposing them to a physiological hypo-osmotic challenge and a wide range of K+ channel...

Abnormal retention of cytoplasmic residues by human spermatozoa is associated with the generation of reactive oxygen species (ROS) in semen and defective sperm function. We have examined the effect of varicocelectomy on the retention of residual cytoplasm by human spermatozoa. Clinical reports of 43 men who underwent microsurgical varicocelectomy at our institution during a 1 year period beginn...

The surface membrane glycoprotein composition of human spermatozoa has been studied by introducing radioactive label into galactosyl (Gal) and N-acetylgalactosaminyl (GalNAc) residues by using the galactose oxidase/NaB3H4 method. Triton X-100 extracts and Triton X-100-resistant cytoskeletal residues were subjected to analysis by polyacrylamide gel electrophoresis. The distribution of the radiol...

background: sperm vitrification is a technique of ice and cryoprotectant free cryopreservation by direct plunging of sperm suspension into liquid nitrogen (ln2). the aim of this study was to investigate the influence of cryoprotectant free-vitrification on human sperm fine structure by msome technology and the fertility potential by zona binding assay (zba). methods: 20 normo-ejaculates were pr...

Background: The study aimed to evaluate the impact of Calligonum extract and US radiation on sperm parametersof cryopreserved human semen samples.Materials and Methods: In this experimental study, twenty-five semen specimens were obtained from healthy semendonors and incubated in human tubal fluid (HTF) medium supplemented with 10% human serum albumin (HSA) for45 minutes...

Human epididymal tissue was recovered from 11 patients undergoing orchidectomy without anti-androgen treatment. Everted epithelial fragments from the caput and corpus epididymis of six patients were successfully cultured in a modified RPMI 1640 medium supplemented with HEPES and androgens for up to 110 days (mean 56 +/- 28) in 5% CO(2) in air at 37 degrees C. Epithelial cells from human oviduct...

Sperm carbohydrate binding activity is involved in gamete recognition. We identified a human sperm protein extracted under reducing conditions, and with a molecular mass of 65 kDa on sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), and which binds D-mannose coupled to albumin (DMA) in presence of cations and a neutral pH. Epifluorescence microscopy showed that fluorescein-...

Human spermatids from ejaculate and testicular tissue have been utilized for evaluating human fertilization by intracytoplasmic sperm injection (ICSI) and, where possible, compared with spermatozoa utilizing sibling oocytes. Round and elongated spermatids obtained from ejaculates were either prepared through Percoll gradients or isolated and washed individually using subzonal insemination needl...

Previous work from our laboratory indicated that gonadotrophin-releasing hormone (GnRH) increases human sperm-zona pellucida binding. Here we present evidence that GnRH antagonists inhibit sperm-zona pellucida binding in humans. Motile spermatozoa (10(7) cells/ml) were incubated in modified Tyrode's medium at 37 degrees C, in 5% CO(2) in air. After 4.5 h, aliquots of spermatozoa were treated wi...