RESUMO
Objective To demonstrate the effect of Pioglitazone hydrochloride on spatial memory ability in diabetes rats via improving the level of hippocampal cholinergic neurostimulating peptide (HCNP) in the hippocampus tissues. Methods Twenty-four 12-week old male SD rats were equally randomized into control group (Con),diabetes group (DM),DM+Pioglitazone hydrochloride treatment group (DP).Rats of the DM and DP groups were fed with high fat diet,and rats of the DP group were also performed intragastric administration of 10 mg/(kg· d) Pioglitazone hydrochloride daily.Morris water maze test was performed on the rats enjoyed successful model making to detect their spatial memory ability; the level of HCNP precursor protein (HCNP-pp) was measured by Western blotting so as to measure the level of HCNP; and the relative mRNA contents of HCNP-pp, choline acetyltransferase (ChAT),muscarinic receptor 1 (M1R) and α7 type nicotinic receptor (α7NR) genes were measured by reverse transcription PCR. Results The escape latency in rats of the con and DP groups was significantly shortened as compared with that in the DM group (P＜0.05).As compared with that in the Con and DP groups, the relative amount of HCNP-pp in DM group was higher in protein and mRNA levels (P＜0.05); however,the relative amount of HCNP in the DM group was obviously lower than that in the Con and DP groups (P＜0.05).And the mRNA ChAT,M1R and α7NR levels in the Con and DP groups were significantly higher than those in the DM group (P＜0.05). Conclusion Pioglitazone hydrochloride can accelerate the lysis of HCNP-pp in the hippocampus to induce the increased level of HCNP,further making the cholinergic nerve receptors activation,which maybe one of the mechanisms to improve the ability of spatial memory in eldly rats with type 2 diabetes.