Roscovitine in combination with calcium ionophore induces oocyte activation through reduction of M-phase promoting factor activity in mice.

The aim of the present study was to determine oocyte activation and change in M-phase promoting factor (MPF) activity induced by treatment with calcium ionophore and roscovitine in comparison with those induced by treatment with roscovitine alone and treatment with calcium ionophore and puromycin in mice. Freshly ovulated oocytes obtained from 6-8-week-old mice were divided into five groups (no activation treatment; 5 μM calcium ionophore A23187; 50 μM roscovitine; 5 μM calcium ionophore and 10 μg/ml puromycin; and 5 μM calcium ionophore and 50 μM roscovitine) and were incubated for 6 h. Oocyte activation, assessed by morphological changes, and changes in MPF activity in the five groups at 0, 2, 4 and 6 h of incubation were examined.

The signaling pathways linking to lysophosphatidic acid-promoted meiotic maturation in mice.

The signaling pathways linking to lysophosphatidic acid-promoted meiotic maturation in mice were studied. When mouse oocyte-cumulus cells complexes were cultured with 10(-5) M lysophosphatidic acid (the LPA group), the rate of oocyte nuclear maturation was significantly increased. Additions of pertussis toxin, genistein, U73122, Ro320432, PD98059 or SB203580 significantly suppressed the increase in lysophosphatidic acid-stimulated nuclear maturation rate.

Distribution of type VI collagen in the cartilaginous tissue of the proximal tibia in the domestic cat.

To investigate the distribution of the early stage chondrocytes during the formation and closure of epiphyseal growth plate (EGP) of the domestic cat, we examined the EGP of proximal tibiae by immunohistochemistry for type VI collagen. In the epiphyseal cartilage without the secondary ossification center (SOC) and EGP in newborn cats aged 1 and 10 days, type VI collagen-positive chondrocytes were located around the cartilage canals and articular surface. In the epiphyseal cartilage with the SOC and EGP in young cats aged 1 to 3 months, type VI collagen-positive chondrocytes were located in the upper resting zone of the EGP, and then increased throughout the resting zone along with maturation.

Differential expression of neurofilament 200-like immunoreactivity in the main olfactory and vomeronasal systems of the Japanese newt, Cynops pyrrhogaster.

Expression of neurofilament 200 (NF200)-like immunoreactivity was examined in the main olfactory system and the vomeronasal system of the Japanese newt, Cynops pyrrhogaster, using anti-porcine NF200 monoclonal antibody (clone N52) to investigate the differences in phenotypical characteristics between these systems. The entire nasal cavity was a flattened single chamber consisting of the main nasal chamber (MNC) and the lateral nasal sinus (LNS) communicating with each other. The olfactory epithelium (OE) was present in the MNC, and the vomeronasal epithelium (VNE) was in the LNS.

Sperm-immobilizing antibodies suppress an increase in the plasma membrane fluidity of human spermatozoa.

Objective: To clarify the mechanism by which capacitation is blocked by sperm-immobilizing antibodies, changes in the plasma membrane fluidity of human spermatozoa exposed to sperm-immobilizing antibodies were evaluated.

Design: In vitro cell culture study using human spermatozoa.

Setting: Department of Obstetrics and Gynecology, School of Medicine, The University of Tokushima.

Human spermatozoa capacitated with progesterone or a long incubation show accelerated internalization by an alkyl ether lysophospholipid.

Objective: To evaluate changes that occur in sperm plasma membranes during capacitation, the internalization of [(3)H]lyso-platelet activating factor ([(3)H]lyso-PAF) across the plasma membrane of human spermatozoa was measured as a function of incubation time or exposure to progesterone (P).

Design: In vitro cell culture study using human spermatozoa.

Setting: Department of Obstetrics and Gynecology, School of Medicine, the University of Tokushima, Japan.

Increased production of bioactive lysophosphatidic acid by serum lysophospholipase D in human pregnancy.

Lysophosphatidic acid (LPA) is a prototype of the lysophospholipid mediator family and has multiple effects in the female reproductive system. Although several metabolic routes have been reported for intracellular formation of LPA, a unique route involving lysophospholipase D, an extracellular enzyme that produces LPA in blood and body fluids, is particularly intriguing for its agonistic role. In this study, using an assay with radioactive palmitoyl-lysophosphatidylcholine, we found that lysophospholipase D activity producing palmitoyl-LPA in human serum gradually increased during pregnancy.

Fertilizing capacity of human sperm preserved in cold electrolyte-free solution.

Objective: To assess the fertilizing capacity of human sperm preserved in electrolyte-free (EF) solution at 4 degrees Celsius.

Methods: The motility, acrosome status and fertility index of human sperm were respectively assessed before and after preservation in cold EF solution.

Results: The motility of human sperm so preserved for one week was significantly higher than that of the sperm preserved in modified human tubal fluid (43.

Production of human mast cell chymase in human myometrium and placenta in cases of normal pregnancy and preeclampsia.

Objective: To investigate whether the human mast cell chymase-endothelin-1(1-31) system was present in human myometrium, chorion and umbilical cord in normal pregnancy.

Methods: Myometrium, placenta and umbilical cord were obtained from five normal pregnant women and 10 with preeclampsia. Each tissue was stained with antibodies against hMC and ET-1(1-31).

Lysophosphatidic acid stimulates nuclear and cytoplasmic maturation of golden hamster immature oocytes in vitro via cumulus cells.

Lysophosphatidic acid (LPA), a member of the phospholipid autacoid family, is induced in incubated human follicular fluid by lysophospholipase D. It is well known that LPA functions as a growth factor and the hypothesis that LPA in human follicular fluid takes a part in meiosis of oocytes is quite plausible. We studied the effects of LPA on the maturation of golden hamster immature oocytes in vitro.

The obesity in bilateral ovariectomized rats is related to a decrease in the expression of leptin receptors in the brain.

We investigated the expression levels of leptin receptors in the brain of ovariectomized (OVX) rats. The mean expression level of ob mRNA in adipose tissues of OVX rats was significantly (P < 0.01) lower than that in the SHAM operation group rats, and the mean body weight of OVX rats was significantly (P < 0.

Involvement of carbohydrate molecules on zona pellucida in human fertilization.

Although the involvement of several receptors and ligand molecules in sperm-zona interaction in many species have been proposed, there has been a little analysis of the kinetics between these molecules during the interaction. In the present study, we applied the detection method using surface plasmon resonance (SPR) by a BIAcore apparatus for the analysis of the putative receptor-ligand interaction of sperm-egg binding. Mannose-BSA or [man](5)-[GlcNAc](2)-Asp was immobilized on the surface of a sensor chip.