Cyclosomatostatin-Induced Catalepsy in the Aged Wistar Rats: Inhibition by Nicotine

Background: Recently, it has been found that Cyclosomatostatin (CSST) induces Catalepsy, a State Similar to extrapyramidal dysfunctions in Parkinson disease. The sensitivity of CSST-induced catalepsy to clinically effective antiparkinsonian agents is unknown. Epidemiological studies have documented an inverse association between parkinsonism and tobacco smoking that suggests an antiparkinsonian activity of nicotine. To evaluate the similarity between human illness and CSST-induced catalepsy, we studied the sensitivity of this model to nicotine. Materials and Methods: The experiments were conducted on 27- to 28-month-old male Wistar rats. To determine the cataleptogenic doses of CSST, this drug (0.5, 2, and 10 µg) was injected intracerebroventricularly. Nicotine (0.1, 0.4, and 1 mg/kg) was given subcutaneously. Catalepsy was defined as an increased period of immobility in the bar test. All groups consisted of 8 animals. Results: CSST (10 µg) increased period of immobility compared with the controls (P<0.01). Nicotine (0.4 and 1 mg/kg) inhibited this effect (P<0.05). Conclusion: CSST-induced catalepsy in Wistar rats can be reduced by nicotine. These data support the validity of this behavioral response as a model of human extrapyramidal dysfunctions.

کلیدواژه ها:

Aging ، Somatostatin ، Nicotine ، Catalepsy ، Parkinson disease