COMPARISON OF NEUROTENSIN EFFECT ON Na+, K+-ATPase ACTIVITY IN SEVERAL EXPERIMENTAL CONDITIONS.

M.G. LÓPEZ ORDIERES; C. ROSIN; J. MIÑO; GIRONACCI; G. RODRÍGUEZ DE LORES ARNAIZ

Buenos Aires

Congreso; XXXIX Reunión Anual de la Asociación Argentina de Farmacología Experimental (SAFE); 2007

Asociación Argentina de Farmacología Experimental (SAFE)

In previous work, we showed that peptide neurotensin inhibits neuronal Na+, K+-ATPase activity. This effect involves high affinity neurotensin receptor and is modified by administration of antipsychotic drugs. Herein we evaluated neurotensin effect on synaptosomal membranes isolated from rat cerebral cortex in two pathological conditions: hyperglycaemia by streptozotocin administration and in spontaneous hypertensive rats (SHR). In membranes isolated after hyperglycaemia induction, 3.5 x 10-8- 3.5 x 10-6 M neurotensin failed to modify Na+, K+-ATPase activity, whereas decreases 8%-36% in enzyme activity were recorded in the control. In membranes isolated from SHR, 3.5 x 10-6 M neurotensin, similar to the control, decreased 40% enzyme activity. Previous administration of clozapine (17.8 mg / kg, 30 min) prevented neurotensin inhibitory effect. Findings indicate that alteration of neurotensin effect on Na+, K+-ATPase activity may be an adaptive phenomenon which occur concomitant with the increase in glucose blood level and / or blood pressure.