Hyperosmolality-induced AVP expression is blunted by early maternal separation.

TRUJILLO, V.1, MIR, F.R.1,2, SUÁREZ, M.M1. VIVAS, L.M.1

Mangarativa

Congreso; 12th World Congress on Neurohypophysal Hormones.; 2017

International Neuroendocrine Federation

Hyperosmolality-induced AVP expression is blunted by early maternal separation.Trujillo, V.1, Mir, F.R.1,2, Suárez, M.M1. Vivas, L.M.1,31Catedra de Fisiología Animal, FCEFyN, Universidad Nacional de Córdoba, Instituto de Investigaciones en Ciencias de la Salud (INICSA).2Cátedra de Fisiología Animal, DCEFyN, Universidad Nacional de La Rioja.3Laboratorio de Balance Hidrosalino e Hipertensión. Instituto de Investigación Médica Mercedes y Martín Ferreyra (INIMEC-CONICET-Universidad Nacional de Córdoba)Studies of last decades give evidence of the important role of the perinatal (intrauterine and/or postnatal) environment in the developing systems being able to result in permanent changes of the physiology and the metabolism of the new individual. Here we assess the implication of an adverse early environment such as the maternal separation on the regulatory response to osmotic stress during adulthood. We hypothesized that the interplay between an early psychological stress and late osmotic stress both associated with the activity of vasopressinergic circuits within the paraventricular nucleus (PVN) would result in a differential osmoregulatory response in terms of vasopressin (AVP) mRNA levels during adulthood The aim of this work was to evaluate whether early maternal separation may induce a differential programming in the adult offspring vasopressinergic system in particular the hyperosmolality-induced AVP expression.Male Wistar rats were subjected to daily maternal separation for 4.5 hours during the first three weeks of life. At postnatal day 74, the rats were cannulated in the femoral vein. The next day animals were infused with isotonic (0.15 M NaCl) or hypertonic (1.5 M NaCl) saline solution during 10 minutes. After 20 minutes, animals were decapitated and brain were removed and frozen at -80°C. Brains were then sectioned in 60 µm slices and PVN were identified and collected by micropunch technique. The tissue was disaggregated in Trizol solution and total RNA were purified by an standard method. Transcripts were retro-transcribed into cDNA and subjected to qPCR. We used specific primers to AVP and GAPDH (as housekeeping gene).We observed that rats of both rearing conditions did not differ in AVP mRNA levels, after isotonic infusion. However, as we expected animals that were reared with their mothers responded to hypertonic stimulation with a threefold increase in AVP mRNA levels (p