Effects of acute salt loading on vasopressin mRNA level in the rat brain

Abstract

To assess the mutual relationship between acute osmotic stimulation and arginine vasopressin (AVP) gene expression, 2 ml/100 g body weight of 0.9 M NaCl was intraperitoneally administered into conscious rats. They were decapitated to collect blood and brain samples before and 15 min and 1, 3, 6, and 9 h after the injection. The total RNA from the hypothalamus or whole brain tissue was used to determine AVP mRNA by Northern blot analyses with a complementary DNA probe. Plasma AVP and osmolality increased rapidly and transiently 15 min and 1 and 3 h after the injection. AVP mRNA was detected in the hypothalamus but not in the brain tissue without hypothalamus under basal and stimulated conditions. Brain AVP mRNA increased 2.2-fold at 3 h and 1.7-fold at 6 h (P < 0.05-0.01). These increases appeared to be due to the appearance of AVP mRNA with the shorter migration in the gel. These results suggest that an acute osmotic challenge increases AVP mRNA with size heterogeneity within the hypothalamo-hypophyseal tract.

Hypothalamic vasopressin release and hepatocyte Ca 2+ signaling during liver regeneration: an interplay stimulating liver growth and bile flow

“…2D). These results suggest that further AVP is synthesized to replenish neuronal stores, as has been previously reported after osmotic or hemorrhagic stress (38).…”

“…As the amount of AVP mRNAs increases rapidly after AVP release in certain conditions (38), the hypothalamus taken at different times after hepatectomy or sham surgery was subjected to semiquantitative AVP RT-PCR. The amount of AVP mRNA remained similar to the basal level during the first few hours after hepatectomy and then increased by 60% in the eighth hour, before returning to the basal level between the second and the third day (Fig.…”

Glucocorticoidal Regulation of Pituitary Vasopressin Content in Rats.

“…AVP mRNA Measurement Northern blot analysis was carried out as reported previously (8,9). Briefly, total cellular RNA was prepared using a modification of the method of Chomczynski and Sacchi (10).…”

Experimental approaches for the study of oxytocin and vasopressin gene expression in the central nervous system

“…Various lesion and inhibitor experiments have pointed to synaptic inputs to the MCNs as critical mediators of this secretory response to hyperosmotic stimuli (Sladek and Johnson, 1983;Oldfield et al, 1994;Richard and Bourque, 1995;Sladek et al, 1995;Bourque and Richard, 2001). The apparent close coupling of both acute and chronic osmotic stimuli to OXT and AVP secretion from the posterior pituitary (Stricker and Verbalis, 1986;Shoji et al, 1994;Leng et al, 2001;Ventura et al, 2005) has been attributed primarily to the action of excitatory amino acids (i.e., glutamate) and the modulation of GABA inputs on the MCNs in the HNS (Sladek and Armstrong, 1987;Bourque, 1992, 1995;Sladek et al, 1998;Swenson et al, 1998;Leng et al, 2001). …”