Effect of non-selective NO-synthase inhibitor administered during pregnancy on the development of the cerebral cortex in 20-day-old rat pups

Aim. To study the morphology of neurons in the cerebral cortex of rat pups on day 20 under conditions of administration  of a nitric oxide synthase inhibitor (NOS) during placentation.

Materials and methods. Outbred white female rats (n = 12) were randomly divided into 2 groups of 6 rats each.  On the 11th day of pregnancy, the experimental group received a single intramuscular injection of N(omega)-nitro-L-arginine methyl ester (L NAME) at a dose of 25 mg/kg, in the control group – once intramuscularly 0.9% NaCl  solution. Born rat pups were randomly selected one from the mother. On the 20th day, after medical euthanasia, the  brain was collected. In the anterior part of the frontal cortex, we studied the density and area of neurons, the size and  shape of perikarya and the severity of their staining with toluidine blue.

 Results. In the experimental group of 20-day-old rat pups, compared to the control group, the density and area of  neurons were less by 10% (p > 0.05) and 22% (p > 0.05), respectively, the shape of the perikarya also changed to  elongated, the elongation factor increased by 0.3 units. (p < 0.05) and there was a sixfold increase in the proportion of  hyperchromic neurons (p < 0.05), hyperchromic wrinkled (p < 0.001) neurons appeared, which were absent in control  animals.

 Conclusion. Morphological changes in neurons of the cerebral cortex in rat pups born from females who received a  NOS inhibitor during placentation may be a consequence of a decrease in the formation of nitric oxide in the neurons  themselves and in the endothelium of the vessels supplying the brain

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