Jerzy B. Warchol

Caspase-3 activation and phosphatidylserine membrane translocation in human spermatozoa: is there a relationship?

The presence of biochemical signs of apoptosis in ejaculated spermatozoa suggests that apoptosis may be one of the pathways for sperm death. The relationship between the phosphatidylserine (PS) externalization and the presence of the active form of caspase-3 (CP-3) was studied in human spermatozoa after exposure to hydrogen peroxide (H(2)O(2)). Semen from 27 normozoospermic men was examined, as the neat semen, after swim-up isolation and after H(2)O(2) incubation, for the translocation of PS, activation of caspase-3 and mitochondrial membrane potential. The percentage of vital spermatozoa expressing PS translocation was lower than the percentage of vital spermatozoa with the active form of the caspase-3, either in neat (4.9 +/- 2.3% versus 19.7 +/- 6.2%, P < 0.001) or in swim-up semen (2.2 +/- 2.3% versus 4.8 +/- 2.9%, P < 0.01). After swim-up isolation, the percentage of vital spermatozoa with active caspase-3 decreased (P < 0.01). After H(2)O(2) stimulation of the swim-up semen fraction, a decrease in the mitochondrial membrane potential was observed (P < 0.001). Only the midpiece revealed PS translocation after H(2)O(2) stimulation, and it was also the only part to reveal the presence of the active form of caspase-3. All spermatozoa expressing the PS translocation revealed the presence of the active form of caspase-3.

Effects of neurokinin-a on the rat hypothalamo-pituitary-adrenal axis

The effects of neurokinin-A (NKA) on the rat hypothalamo-pituitary-adrenal (HPA) axis were studied in vivo and in vitro. A subcutaneous injection of 1 or 3 nmol/100 g NKA did not alter plasma ACTH concentration. The lower dose of NKA evoked a transient rise in plasma corticosterone (B) concentration (PBC) at 30 min, and did not change plasma aldosterone (ALDO) concentration (PAC). The higher dose of NKA increased PBC at 30 and 60 min, and PAC at 30, 60 and 120 min. NKA did not affect basal ALDO secretion of dispersed zona glomerulosa (ZG) cells, but it markedly enhanced basal B production by dispersed zona fasciculata/reticularis (ZF/R) cells (minimal and maximal effective concentrations were 10(-9) M and 10(-6) M). Video-imaging analysis showed that 10(-6) M NKA increased intracellular Ca2+ concentration in dispersed ZF/R cells, but not in ZG ones. These findings indicate that NKA exerts a stimulatory action on the rat adrenal secretory activity, which is independent of any effect on the pituitary ACTH release: the B secretagogue action seems to be due to a direct effect of NKA on ZF/R cells, while the ALDO secretagogue action is not direct. but probably mediated by factor(s) other than ACTH.

Ca2+-modulated membrane guanylate cyclase in the testes

To date, the calcium-regulated membrane guanylate cyclase Rod Outer Segment Guanylate Cyclase type 1 (ROS-GC1) transduction system in addition to photoreceptors is known to be expressed in three other types of neuronal cells: in the pinealocytes, mitral cells of the olfactory bulb and the gustatory epithelium of tongue. Very recent studies from our laboratory show that expression of ROS-GC1 is not restricted to the neuronal cells; the male gonads and the spermatozoa also express ROS-GC1. In this presentation, the authors review the existing information on the localization and function of guanylate cyclase with special emphasis on Ca2+-modulated membrane guanylate cyclase, ROS-GC1, in the testes. The role of ROS-GC1 and its Ca2+-sensing modulators in the processes of spermatogenesis and fertilization are discussed.

Trichrome Mallory's stain may indicate differential rates of RNA synthesis in eutopic and ectopic endometrium.

Mallorys triple staining is a histochemical technique used mainly for analysing connective tissues and glands and other tissues. We have described the differences in the nuclear staining between eutopic and ectopic endometrium as well as endometrial hyperplasia and adenocarcinoma using the Mallorys method. The ultrastructural differences between eutopic and ectopic endometrium have been detected. In normal and hyperplastic endometrium the presence of stromal cell nuclei with an increased affinity to aniline blue has been observed. The affinity has disappeared after digestion of tissues with RNase. In cases of endometriosis, independently of cell types, the nuclei have shown affinity to orange G. Similar effects in adenocarcinoma have been noted. The ultrastructural studies have shown that in normal endometrium the stroma contained cells with euchromatic and low electron density cell nuclei. In endometriosis heterochromatic cell nuclei present both in the stroma and within glands have been detected. The results indicate that the Mallorys technique may be a useful tool for recognizing the differences between eutopic and ectopic endometrium. The affinity for aniline blue in normal and hyperplastic endometrium occurs most likely due to increased RNA synthesis. Based on Mallorys staining a similarity between hyperplasia and unchanged endometrium in contrast to similar results of the staining obtained in cases of adenocarcinoma and endometriosis may be suggested.