Brain arginine vasotocin concentrations related to sexual behaviors and hydromineral balance in an amphibian

Arginine vasotocin (AVT), a potent stimulator of sexual behaviors and regulator of hydromineral balance in male rough-skinned newts (Taricha granulosa), was measured in 11 brain areas using microdissection and radioimmunoassay procedures. A 60-min test for sexual behaviors was used to segregate males into two groups: sexually responsive (initiated amplectic clasping behaviors) and sexually unresponsive (exhibited no sexual behaviors). Compared to sexually unresponsive males, sexually responsive males had significantly higher concentrations of immunoreactive (ir) AVT in the dorsal preoptic area, optic tectum, ventral infundibular nucleus, and cerebrospinal fluid. These results provide evidence for a behavioral action of endogenous AVT in T. granulosa. In another study, irAVT was measured in normal males (control newts maintained in water) and males that were dehydrated for 6 hr. Compared to normal males, dehydrated males had significantly lower concentrations of irAVT in the ventral preoptic area, but not in the other 10 areas of the brain. That different brain areas are associated with sexual behaviors and hydromineral balance suggests that there are some neuroanatomical separations between the behavioral and hydromineral aspects of the vasotocinergic system in this amphibian.     

Basement membrane proteoglycans: Modulators <Emphasis Type="Italic">Par Excellence</Emphasis> of cancer growth and angiogenesis

Proteoglycans located in basement membranes, the nanostructures underling epithelial and endothelial layers, are unique in several respects. They are usually large, elongated molecules with a collage of domains that share structural and functional homology with numerous extracellular matrix proteins, growth factors and surface receptors. They mainly carry heparan sulfate side chains and these contribute not only to storing and preserving the biological activity of various heparan sulfate-binding cytokines and growth factors, but also in presenting them in a more Ȍactive configurationȍ to their cognate receptors. Abnormal expression or deregulated function of these proteoglycans affect cancer and angiogenesis, and are critical for the evolution of the tumor microenvironment. This review will focus on the functional roles of the major heparan sulfate proteoglycans from basement membrane zones: perlecan, agrin and collagen XVIII, and on their roles in modulating cancer growth and angiogenesis.