Effects of Galarmin and Cobra Venom on the Morphofunctional State of the Substantia Nigra in a Rat Model of Parkinson’s Disease

Abstract

Morphofunctional characteristics of the substantia nigra (SN) were compared in four groups of experimental rats: (i) control (sham-operated), (ii) animals with a rotenone model of Parkinson's disease, PD (induced by stereotaxic unilateral microinjections of 12 μg into the median forebrain bundle), (iii) rats with modeled PD treated with i.m. injections of 100 μg/kg galarmin, and (iv) similar rats but treated with i.m. injections of a small dose of cobra venom (Naja oxiana venom, 1.0 mg/k, i.e., 5% of LD50). Four weeks after rotenone injection, frontal SN sections of all animals were examined using light microscopy and a technique for detection of Ca 2+ -dependent acid phosphatase. Clear structural disorders in the SN (decreased density of neurons, negative changes in their shape, depigmentation, low activity of acid phosphatase, etc.) were observed in rats of the second group (with the PD model). Such changes were significantly less intense in rats of the third and fourth groups (those also with the PD model, but treated with course introductions of galarmin or small doses of cobra venom); the former agent (galarmin) demonstrated somewhat better neuroprotective effects.