Biomaterial Database

Elevated ovarian follicular apoptosis and heat shock protein-70 expression in white sucker exposed to bleached kraft pulp mill effluent. 1997

D M Janz, and M E McMaster, and K R Munkittrick, and G Van der Kraak

Department of Zoology, University of Guelph, Ontario, Canada.

Exposure of feral fish populations to bleached kraft pulp mill effluent (BKME) results in a variety of negative impacts on reproductive fitness including reduced ovarian development, reduced egg size, decreased fecundity with age, delayed sexual maturation, and alterations in reproductive endocrine homeostasis at multiple sites along the pituitary-gonadal axis. The present study provides evidence of elevated apoptotic DNA fragmentation and increased expression of the 70-kDa heat shock protein (HSP70) in ovarian follicular cells from prespawning white sucker (Catostomus commersoni) exposed to BKME. Apoptosis is the molecular mechanism responsible for ovarian follicular atresia which is involved in various stages of vertebrate ovarian development such as follicular recruitment, growth, differentiation, and regression. In mammals, induction of HSP70 is associated with inhibition of hormone-sensitive steroidogenesis and mediation of luteal regression. The 3'-end labeling of isolated ovarian follicular cell DNA revealed a 10-fold increase in the extent of apoptosis in BKME-exposed white sucker in comparison to follicles collected from a nearby reference site. Western blotting for ovarian follicular HSP70 levels showed increased expression of this protein in fish exposed to BKME. The elevated ovarian cell apoptosis and increased HSP70 expression in BKME-exposed fish were associated with reduced ovary size, decreased plasma testosterone, and increased plasma 17 beta-estradiol concentrations, but not induction of hepatic ethoxyresorufin O-deethylase activity. It is not known whether increased ovarian HSP70 expression in BKME-exposed fish is related to elevated apoptosis or represents a general response to environmental stress. Since apoptosis is regulated by several hormonal factors and conserved gene products, these data suggest that certain components of BKME increase ovarian cell apoptosis in fish via stimulation of cell death signaling. However, it is unclear whether BKME stimulates ovarian cell apoptosis directly or if this response occurs secondarily as a result of altered reproductive endocrine homeostasis.

UI	MeSH Term	Description	Entries
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D009864	Ontario	A province of Canada lying between the provinces of Manitoba and Quebec. Its capital is Toronto. It takes its name from Lake Ontario which is said to represent the Iroquois oniatariio, beautiful lake. (From Webster's New Geographical Dictionary, 1988, p892 & Room, Brewer's Dictionary of Names, 1992, p391)
D010053	Ovary	The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.	Ovaries
D010209	Paper	Thin sheets made from wood pulp and other fibrous substances, used for writing, drawing, printing, image duplication or wrapping.	Papers
D005260	Female		Females
D005399	Fishes	A group of cold-blooded, aquatic vertebrates having gills, fins, a cartilaginous or bony endoskeleton, and elongated bodies covered with scales.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014873	Water Pollutants	Substances or organisms which pollute the water or bodies of water. Use for water pollutants in general or those for which there is no specific heading.	Water Pollutant,Pollutant, Water,Pollutants, Water
D017209	Apoptosis	A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, i.e., DNA FRAGMENTATION. It is genetically programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.	Apoptosis, Extrinsic Pathway,Apoptosis, Intrinsic Pathway,Caspase-Dependent Apoptosis,Classic Apoptosis,Classical Apoptosis,Programmed Cell Death,Programmed Cell Death, Type I,Apoptoses, Extrinsic Pathway,Apoptoses, Intrinsic Pathway,Apoptosis, Caspase-Dependent,Apoptosis, Classic,Apoptosis, Classical,Caspase Dependent Apoptosis,Cell Death, Programmed,Classic Apoptoses,Extrinsic Pathway Apoptoses,Extrinsic Pathway Apoptosis,Intrinsic Pathway Apoptoses,Intrinsic Pathway Apoptosis
D018840	HSP70 Heat-Shock Proteins	A class of MOLECULAR CHAPERONES found in both prokaryotes and in several compartments of eukaryotic cells. These proteins can interact with polypeptides during a variety of assembly processes in such a way as to prevent the formation of nonfunctional structures.	Heat-Shock Proteins 70,Heat Shock 70 kDa Protein,Heat-Shock Protein 70,HSP70 Heat Shock Proteins,Heat Shock Protein 70,Heat Shock Proteins 70,Heat-Shock Proteins, HSP70