A role for nitrergic system in the antidepressant-like effects of chronic lithium treatment in the mouse forced swimming test.

In the present study we evaluated the involvement of nitric oxide (NO) system in the antidepressant-like effects of chronic lithium administration in the mouse forced swimming test (FST). Administration of lithium chloride (300 mg/L in drinking water for 21 days) had no effect on the immobility of mice in the FST, whereas 600 mg/L lithium caused a significant (P<0.001) decrease in the immobility time compared with control animals. Administration of the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME, 10mg/kg, daily for a week, i.p.) had no significant effect on the immobility time of either control or lithium (300 mg/L)-treated mice, whereas acute administration of non-effective dose of L-NAME (30 mg/kg, i.p.) caused a robust decrease (P<0.01) in the immobility time of lithium (300 mg/L)-treated animals in the FST. Moreover, chronic administration of low dose of the NO precursor L-arginine (200 mg/kg, daily for a week, i.p.) prevented (P<0.001) the antidepressant-like effects of lithium treatment (600 mg/L) in the FST. Acute treatment with L-arginine (200 mg/kg, i.p.) increased (P<0.05) the immobility time of lithium (600 mg/L)-treated mice in the FST. Chronic lithium treatment (600 mg/L but not 300 mg/L) caused a significant (P<0.05) decrease in the serum NO(X) levels in mice compared with controls. Our data suggested that the NO system could be involved in the antidepressant-like effect of chronic lithium treatment in the FST.

Iranian military forces in the Bam earthquake.

The earthquake that struck Bam, Iran, in December 2003 was one of the most catastrophic natural disasters in recent years. Medical and assistance activities conducted by Iranian military forces in this event are discussed in light of the special capabilities of the military forces in search and rescue missions. Among the most significant activities of the Iranian military forces in this event are the following: reporting the first news about the event, starting search and rescue missions in the first hour after the disaster by the 1st Brigade of Bam as the first assisting force, setting up two field hospitals as the first Iranian field hospitals in the disaster area, transporting 937 assistance, medical, and health care personnel to the disaster area in the first day, setting up 23 field emergency and 13 field assistance centers in the area, running 8 post-hospital care centers throughout the country, and playing a significant role in airlifting 11,792 casualties to different hospitals around the country. Based on the recent experience and the exclusive abilities of military forces, a special role for these forces in search and rescue missions should be considered.

Effects of nitric oxide on morphine self-administration in rat.

Previous studies have reported that morphine exerts its effects in part through the release of nitric oxide (NO). In the present study, the effects of acute and chronic administration of the NO precursor, L-arginine and NO synthase (NOS) inhibitor, L-nitro-amino-methyl-ester (L-NAME) on morphine self-administration in rats were investigated. The animals were initially trained to press a lever using food as reinforcer. Rats were surgically prepared with a chronic Silastic catheter implanted in the external jugular vein. Five days after surgery, they were trained to press a lever for drug self-administration. The present data indicate that L-arginine (0.05, 0.1, and 0.15 mg/kg/injection) but not L-NAME (0.05, 0.1, and 0.15 mg/kg/injection) induced self-administration behavior and increased locomotion. The response induced by L-arginine (0.1 mg/kg/injection) was reduced by pretreatment with L-NAME (5, 10, and 15 mg/kg ip). Both the acute (5, 10, and 15 mg/kg ip) and the chronic (200 mg/kg ip; twice daily for 4 days) administration of L-arginine reduced morphine self-administration. However, acute (5, 10, and 20 mg/kg ip) and chronic (50 mg/kg ip; twice daily for 4 days) administration of L-NAME increased morphine self-administration significantly. It can be concluded that NO may have a role in morphine self-administration.