Vasopressin and nitric oxide synthesis after three days of water or food deprivation

Abstract

Expression of antibodies or antibody fragments in plants is a useful tool for producing active antibody derivatives for diagnostic or pharmaceutical purposes as well as for immunomodulation. We investigated the effect of cellular expression site on the stability and yield of double-stranded RNA (dsRNA)-specific single-chain Fv-fragments (scFv) in transgenic tobacco. Two antibodies (J2 and P6) belonging to the V23(J558) heavy chain variable gene family but differing in the light chain variable domain were used. scFvs were targeted to the cytoplasm -with or without anchoring them in the plasma membrane -, into the endoplasmic reticulum (ER) and to the apoplast. Although high mRNA concentrations were detected in all cases, scFv proteins accumulated only when scFvs were made ER-resident by appropriate signal sequences. When the ER retention signal was removed to allow scFv-secretion to the apoplast, no scFv-proteins were detected. Despite the strong homology of the V H -sequences of J2 and P6 antibodies, only P6 provided a stable scFv scaffold for intracytoplasmic expression. J2-scFv could not be stabilised neither by adding a C-terminal stabilisation signal nor by anchoring the protein at the cytoplasmic side of the plasma membrane (PM). It was found that dsRNA-specific J2-scFvs are active in vivo and enhance Potato Virus Y induced symptoms in infected tobacco. This is the first report describing the expression and biological effect of RNA-specific antibodies in plants.

Long-term physical training increases liver IGF-I in diabetic rats

“…Previous work has shown that the beneficial effect of physical training on muscle glycogen levels is mediated by enhanced PI3-kinase activity, leading to greater glycogen synthesis in this tissue [50]. The lack of significant changes in the serum albumin concentrations and hematocrit indicated that the significant alterations seen in various parameters were not the result of animal dehydration [51,52].…”

Effects of physical training on the immune system in diabetic rats

“…[20] The study demonstrates that diabetes decreased liver glycogen content and the physical training counteracted this alteration. Many studies have demonstrated that liver glycogen is important to maintain physical performance during prolonged exercise.…”

Influence of nitric oxide synthase inhibition on vasopressin and corticosterone secretion during water deprivation in rats

“…NOS is an unstable gas which plays an important role in modulating many neuroendocrine responses as well as central, cardiovascular, and peripheral nervous systems [31,44]. It has been reported that NO also works as a neuromodulator in the hypothalamic-pituitary-adrenal axis (HPA axis) [3,6] and in vasopressinergic axis [50].…”

“…In our previous work, vasopressin and nitric oxide metabolite levels were determined in plasma of male Wistar rats submitted to water or food deprivation for 3 days, and we have suggested that the release of nitric oxide may participate in the regulation of the alteration in blood flow and fluid and nutrient metabolism caused by water deprivation [31]. Thus, the present study was designed to complete our previous work [31] by investigating the effect of L-nitro-arginine methyl ester (L-NAME), a nonspecific nitric oxide synthase NOS inhibitor on the vasopressinergic and the HPA axis responses after 3 days of water deprivation.…”

“…Thus, the present study was designed to complete our previous work [31] by investigating the effect of L-nitro-arginine methyl ester (L-NAME), a nonspecific nitric oxide synthase NOS inhibitor on the vasopressinergic and the HPA axis responses after 3 days of water deprivation. Thus, our hypothesis was to study and to confirm the stimulatory role of NO on HPA axis and AVP release in a stress condition.…”