In lowland Cobs butterflies, genotypes of the enzyme phosphoglucose isomerase (PGI) show major differences in molecular function, from which genotypic differences in organismal performance and fitness components in the wild are accurately predictable. The alpine species Colias meadii seems to share electromorph alleles with lowland congeners at PGI and phosphoglucomutase (PGM). However, high-re...

Phosphoglucose isomerase (PGI; EC 5.3.1.9) is a cytosolic housekeeping enzyme of the sugar metabolism pathways that plays a key role in both glycolysis and gluconeogenesis. PGI is a multifunctional dimeric protein that extracellularly acts as a cytokine with properties that include autocrine motility factor (AMF)-eliciting mitogenic, motogenic, and differentiation functions, and PGI has been im...

One mechanism by which high density lipoproteins (HDLs) exert their protective effect against coronary artery disease could be related to the induction of prostacyclin (PGI(2)) release in the vessel wall. We have recently shown that HDL increases PGI(2) production in rabbit smooth muscle cells (RSMCs) and that this increase is dependent on cyclooxygenase-2 (Cox-2). Here we analyze the mechanism...

This study aimed to determine whether PGI(2) would be evoked by the endogenous endothelial B(2) receptor agonist bradykinin (BK) in the porcine interlobular renal artery and, if so, to determine how it would influence the vasomotor reaction, and the specific cyclooxygenase (COX) isoform(s) involved in its synthesis. The production of the PGI(2) metabolite 6-keto-PGF(1α) was analyzed with HPLC-m...

Formal genetic analysis of the mode of inheritance of the electrophoretic phenotypes for phosphoglucoisomerase (PGI) in the annual plants Clarkia rubicunda and C. xantiana showed that these diploid species have two and three genes, respectively, that specify PGI subunits. Electrophoretic examination of seven other diploid species of Clarkia revealed that species assigned to ancestral sections i...

Prostacyclin, or PGI(2), is an end product derived from the sequential metabolism of arachidonic acid via cyclooxygenase and PGI synthase (PGIS). The receptor for PGI(2), IP, can be found on a variety of cell types and signaling through this receptor exhibits broad physiological effects. Historically, PGI(2) has been understood to play a role in cardiovascular health, specifically having powerf...

Prostaglandins participate in a variety of female reproductive processes, including ovulation, fertilization, embryo implantation and parturition. In particular, maternal prostacyclin (PGI(2)) is critical for embryo implantation and the action of PGI(2) is not mediated via its G-protein-coupled membrane receptor, IP, but its nuclear receptor, peroxisome-proliferator-activated receptor δ (PPARδ)...

In the present study we hypothesized that endothelial progenitor cells (EPCs) enhance production of vasoprotective substances in cerebral arteries. Isolated mononuclear cells from rabbit peripheral blood were cultured in endothelial growth medium (EGM-2) for 7 days to yield EPCs. Rabbit basilar arteries were exposed to autologous EPCs ( approximately 5x10(5) cells) in vitro or in vivo. Twenty-f...

Endothelial cells synthesize prostacyclin (PGI(2)), an unstable prostaglandin that inhibits platelet aggregation and serotonin release. Because cyclooxygenase, which is necessary for synthesis of PGI(2), is inactivated by aspirin, we examined the effect of aspirin on PGI(2) production by cultured human endothelial cells. Endothelial cells synthesize PGI(2) (20.1+/-7.2 ng/10(6) cells, mean+/-SD)...

in the present study, the effects of formalin as a peripheral noxious stimulus on spontaneously active units of the nucleus reticularis paragigantocellularis (pgi), a narrow region of the ventral pontine reticular formation, was examined in urethane anesthetized rats. spontaneous discharge of the pgi neurons was variable, ranging from i to 37 spikes per second. formalin as a chemical irritant a...