Hydrolysis of Extracellular Adenine Nucleotides by Human Spermatozoa: Regulatory Role of Ectonucleotidases in Sperm Function

Evidence is presented for the existence of ectonucleotidases on the membrane of intact human spermatozoa. Enzymes hydrolyze extracellular ATP, ADP and AMP and hence could be described as ecto-NTPDase and ecto-5\u27-nucleotidase. Suramin, Cibacron 3GA and DIDS, well known ecto-NTPDase inhibitors, caused inhibition of the observed enzyme activity. Enzymatic hydrolysis of ATP, ADP and AMP follows simple Michaelis-Menten kinetics with similar enzyme affinity for all three substrates (Km for ATP, ADP and AMP were (0.395 ± 0.027), (0.401 ± 0.031), (0.517 ± 0.038) mmole dm−3, respectively). Influence of extracellular ATP, AMP, adenosine and cAMP on the parameters of sperm velocity and acrosome reaction was also examined. In normozoospermic samples, ATP and cAMP induced an increase in the amplitude of lateral head displacement and number of acrosomally reacted cells, but not in sperm velocity. However, adenosine and AMP enhanced sperm velocity, without influencing the acrosome reaction. These results show that ATP and adenosine regulate sperm motility parameters in different ways

A rare Y-autosome translocation found in a patient with nonobstructive azoospermia: Case report

ABSTRACT INTRODUCTION ABSTRACT Y‑autosome translocations are relatively uncommon in humans, with t(Y;1) stated to be even rarer. On the contrary, pericentric inversion 9 is the most commonly seen inversion of chromosome . Although considered to have no significant effect on male fertility, the literature reporting on reproductive risks for both aberrations remains controversial. We report here, as far as we know, the first case of a unique combination of balanced reciprocal translocation t(Y;1) with pericentric inversion of chromosome 9 in a patient with nonobstructive azoospermia (NOA) and an otherwise normal phenotype. Our patient was a 37-year-old Caucasian male sent to our Department due to azoospermia reported by semen analysis. The cytogenetic analysis revealed a balanced reciprocal translocation including chromosomes Y and 1 in all observed metaphases: 46, X,t(Y;1)(q12;q21) and a pericentric inversion of chromosome 9: inv(9)(p12q13). By performing metaphase FISH, the t(Y;1) translocation was confirmed. By means of multiplex-PCR, no Y-chromosome microdeletions were detected in the AZF regions. This report demonstrates a unique karyotype showing balanced reciprocal translocation t(Y;1)(q12;q21) with pericentric inversion 9: inv(9)(p12q13), in a patient with NOA, and highlights the importance of appropriate genetic counseling for patients with regard to the medical management of balanced chromosomal aberrations