INIMEC - CONICET   05467
INSTITUTO DE INVESTIGACION MEDICA MERCEDES Y MARTIN FERREYRA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Chronic perinatal manipulation of hydromineral environment modifies the offspring’s water drinking behaviour during adulthood
Lugar:
San Diego, CA
Reunión:
Congreso; 40th Annual Meeting Society for Neuroscience; 2010
Resumen:
The intrauterine and/or perinatal conditions in which an individual develops can provoke differences in physiological and behavioural responses later in life. Several studies have shown that disturbances in maternal salt and water environment caused by the availability of a rich source of sodium or changes in the renin angiotensin system (RAS) would generate long-term alterations in the offspring’s homeostatic mechanisms. The aim of this study was analyze the effect of two perinatal manipulation models (PM) on drinking behaviour stimulated by absolute or relative dehydration during adulthood (2 months old). The offspring were bred in 2 conditions of perinatal manipulation (PM): a- perinatal exposure to hypertonic sodium solution (Exp-NaCl group); or b- endogenous RAS hyperactivity induced by maternal partial ligation of the abdominal aorta (PAL group). Both models of PM were compared with progenies bred in control conditions, without ligation or NaCl exposure (Ctrol group). In experiment #1, the progenies after PM treatments were subjected to overnight water deprivation with food ad lib. Afterwards, the rats were subjected to a water intake test (120 min). Although cumulative water volume ingested during the test was similar in all groups, in the first 5 min of test PAL and Exp-NaCl groups consumed lower volumes compared to Ctrol group (p<0,05). In experiment #2, the rats obtained from different models of PM were subjected to a relative dehydration thirst model. Animals were infused either with hypertonic (HS,1.5M) or isotonic (0.15M) NaCl solution (iv/3 ml/20 min) and had access to water during both the infusion period and for the following 120 min. Results indicated that, after HS infusion, Exp-NaCl’s offspring consumed significantly more water during the last hour of the test when compared with others groups (p<0,001). Interestingly, no significant differences were observed in the urine volume during this experiment. To sum up, our results indicate that the offspring of both PM models show slight changes in water intake latency after a strong stimulation such as absolute dehydration. Moreover, during a relative dehydration (where the stimulus is mainly osmotic and less intensive) the Exp-NaCl’s offspring, bred in a hypertonic sodium environment, exhibit greater water intake. Taking together, this data suggest that altered responsiveness to different thirst models could reflect differential osmoreceptor sensitivity triggered by changes in perinatal ionic environment. In conclusion, the behavioural responses observed could be correlated with the hydrosaline system alterations caused during ontogeny. Supported by CONICET and ANPCyT.