[Experimental study of the influence of phenozanic acid and its combination with valproic acid on the development of the epileptic system]. / Izuchenie vliyaniya fenozanovoi kisloty i ee kombinatsii s val'proevoi kislotoi na razvitie epilepticheskoi sistemy v eksperimente.

OBJECTIVE: To study the effect of phenosanic acid (PA) and its combination with valproic acid (VA) on the development of the Epi system. MATERIAL AND METHODS: A model of focal chronic epilepsy in rats was created by applying metallic cobalt to the surface of the sensorimotor area of the cortex. Long-term electrodes were implanted in the sensorimotor cortex of the left and right hemispheres, the hippocampus, and the hypothalamus. The effect of PA (80 mg/kg) and its combination with VA (200 mg/kg) on discharge activity was carried out on the 2nd day and at the stage of generalization of the Epi system - on the 6th day. The stability of the Epi system on day 10 was assessed by provoking the development of epileptic status (Epi status) in response to the administration of thiolactone homocysteine (HMC) at a dose of 5.5 mmol/kg. RESULTS: In rats treated with PA, low discharge activity is observed, which is confirmed by the absence of EEG and motor manifestations of status epilepticus caused by HMC. PA does not suppress paroxysmal activity at the stages of development of the Epi system. VA significantly suppresses paroxysmal activity, but does not affect the formation of new foci of Epi activity in subcortical structures and the contralateral cortex. The epi system of rats treated with VA is characterized by high discharge activity by the 10th day of the experiment and lability to provocation of epi status. The combination of drugs is more pronounced than PA, but less than VA, reduces the numerical characteristics of paroxysmal activity in the brain structures of rats. CONCLUSION: PA when administered alone, in combination with VA, causes a slowdown in the generalization of convulsive foci of Epi activity and prevents the formation of a stable Epi system. VA, having a pronounced anticonvulsant effect, does not weaken the development of the Epi system in the model of focal cobalt-induced epilepsy.

[Effect of hypoxia on the contractile activity of smooth muscle cells of the thoracic lymphatic duct]. / Vliianie gipoksii na sokratitel'nuiu aktivnost' gladkomyshechnykh kletok grudnogo limfaticheskogo protoka.

Hypoxia (95% N2; 5% CO2) led to complete or partial inhibition of spontaneous contractile activity of isolated segment of the rat thoracic lymphatic duct, PO2 of perfused solution being 5--10 mm Hg. Reoxygenation restored rhythmical although more frequent contractions of the smooth muscle cells. Excitability of cells membrane tested with KCl, BaCl2, and noradrenaline during hypoxic period proved lower during this decreased PO2. Preliminary depolarization with KCl, BaCl2, and noradrenaline of cells membrane delayed the inhibition of contractile activity during hypoxia. Compared with the portal vein, lymphatic duct revealed a greater resistance to hypoxia. The hypoxia seems to affect first the smooth muscle cell membrane which leads to modification of the contraction character.