Vasopressin adaptive response

The delay in the adaptive response of about an hour s time is readily apparent. This system which involves dilution of body fluids sensed by the hypothalamic osmoreceptors which in turn shut off vasopressin release is one of the body s most nimble. Figure 8 contrasts the much more sluggish response of the system concerned with adapting to a sudden change in sodium intake where achievement of a new equilibrium requires five days. 

Fig. 2 Increased synthesis, content and release of vasopressin (AVP) in the PVN of high-anxiety (HAB) vs low-anxiety (LAB) rats under basal circumstances. Above left in situ hybridization. Above right immunocytochemistry (courtesy of Dr. N. Singewald, University of Innsbruck). Middle and below intra-PVN release of AVP and oxytocin (OXT) measured by in vivo microdialysis under basal conditions and in response to hypertonic stimulation to reveal the releasable neuropeptide pool. p<0.05, p<0.01 vs LAB. (Adapted from Wigger et al. 2004)...

Indeed, previous studies on animal models have demonstrated the critical role of QT and the related peptide vasopressin (VP) in stress, coping responses and social, adaptive behaviours influencing social affiliation and social recognition, sexual and maternal behaviours and anxiety and reactivity to stressors (Carter and Keverne, 2002 Pedersen and Boccia, 2006). 

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