Effect of deltamethrin on the release of catecholamines and its related effect on some sex hormones in adult male albino rats

The oral administration of 1/5 LD50 of deltamethrin for 15 days resulted in an increase in Na+ and Ca++ ions concentrations, whereas it resulted in significant decreases in norepinephrine (NE) and dopamin (DA) contents in all tested brain areas (cerebellum, pans + medulla oblongata, striatum, cerebral cortex, hypothalamus, midbrain and hippocampus) of adult male albino rats at most time intervals. Deltamethrin also resulted in significant decreases of serum leutinizing hormone (LH) and testosterone levels in adult male albino rats. It could be concluded from the present results that deltamethrin resulted in significant increases in Na+ and Ca++ ions concentration. This observation might be due, in part, to an increase of the intracellular Na+ flow through its binding to Na+ ions channels and prolonging the opening time. Also, deltamethrin may stimulate the activity of protein kinase C/phosphoinositide that results in an increase of the intracellular concentrations ofinositol I, 4, 5-triphosphate (IPS) and free Ca++ ions. The increment in intracellular Ca+ ions led to an increase in the release of neurotransmitters by exocytosis, thai eventually decreased the contents of NE and DA in pre-synaptic cells. It is also clear that deltamethrin may act on the hypothalamus-pituitary axis. The decrement in DA content in hypothalamus led to decrease in the release of leutinizing hormone releasing hormone (LHRH) which resulted in decreasing in LH and testosterone levels in serum of the treated rats