Defective calcium influx and acrosome reaction (spontaneous and progesterone-induced) in spermatozoa of infertile men with severe teratozoospermia

Fertil Steril. 1994 Feb;61(2):349-54. doi: 10.1016/s0015-0282(16)56530-3.

Abstract

Objective: To evaluate the acrosome reaction and its prerequisite, a calcium influx, in spermatozoa of infertile men with a high incidence of abnormal sperm forms.

Design: Prospective, controlled study.

Setting: Academic tertiary assisted reproduction center.

Patients: Patients (n = 14) were allocated in the study after semen evaluation showed teratozoospermia (< 14% normal sperm forms) as diagnosed by strict criteria.

Interventions: After swim-up separation of the motile fraction, acrosome reactions were evaluated using Pisum sativum agglutinin (both spontaneously and exogenously induced with P and the calcium ionophore A23187, both at 10 microM); the intracellular-free [Ca2+]i was assessed by the fluorescent fura-2 indicator (basal and after P).

Results: Patients did not show the typical P-induced wave of [Ca2+]i that was observed in controls but rather a blunted response, no response at all, or abnormal basal [Ca2+]i levels. The percent of basal acrosome reaction was significantly lower for patients versus controls postswim-up, and at 1 hour and 3 hours. Furthermore, there was a significant difference in the response of acrosome reaction to P both at 1 hour and 3 hours, with patients showing almost no response at all. However, patients' acrosome reaction response to the calcium ionophore was similar to those of fertile men.

Conclusion: Infertile patients with a high incidence of abnormal sperm forms as diagnosed by strict criteria have a low incidence of spontaneous acrosome reaction and a diminished P-stimulated acrosome reaction, whereas the nonspecific response to a calcium ionophore is conserved. Parallel abnormalities of [Ca2+]i were observed in patients, suggesting that these sperm populations may have a defective nongenomic P sperm receptor and/or abnormalities of other membrane transduction systems.

MeSH terms

  • Acrosome / drug effects
  • Acrosome / physiology*
  • Calcimycin / pharmacology
  • Calcium / metabolism*
  • Humans
  • Infertility, Male / physiopathology*
  • Male
  • Progesterone / pharmacology*
  • Prospective Studies
  • Spermatozoa / abnormalities*
  • Spermatozoa / metabolism

Substances

  • Calcimycin
  • Progesterone
  • Calcium