| Background and Purpose: Intracerebral hemorrhage (ICH) is a kind of frequently encountered disease with much high morbidity, which occupy about 10%-15% in cerebral vascular disorders,while high up to about 40% in China and Japan. Together with the higher disability rate and mortality rate, intracerebral hemorrhage is severely threatening human health. The appropriate therapy for intracerebral hemorrhage remains a subject of debate. Brain energy consumption is extremely high. Neural cell is extraordinary sensitive to energy accommodation disorder. Moreover,because of the poor regeneration ability of the neural cells, energy metabolic abnormality in brain might affect the nerve's function. To explore the pathophysiological mechanisms after ICH would advance the therapy methods and improve patient' life quality. Mitochondria is named as "energy factory" for being the center of producing adenosine triphosphate(ATP) in cells. Up to now,there is not enough understanding for the changes of mitochondria in ICH brain. In this study, it was studied on the changes of the structure and function of the mitochondrial, as well as the expression of ATPase-6 gene in mitochondria in tissue around the hematoma.Methods: It was composed of four parts: 1.Rat ICH model:By injected 50μl tail blood into rat caudoputamen. Rats were killed respectively at 12h,1d,3d,1w after injection; and rat' neurologic impairment score was measured before sacrificed. The control group (CO group) was by the same way only without blood injection. 2.Measurement of the mitochondrial function in tissue around the hematoma: (1) Preparation of Mitochondria----Rapidly removed the rat' brains into ice -cold isolation in 30s.After rinsing in the isolation, the tissue was placed in a homogenizer together with cold isolation medium, and manually homogenized by eight up and down strikes with a glass pestle. Then a discontinuous Ficoll density gradient procedure which was controlled between 0 to 4 centigrade; (2)The concentration of mitochondria was measured by the Lowery method; (3)The mitochondria were set to a concentration of 3mg of protein per ml in the isolation medium. The respiration control rate (RCR) of mitochondria was measured with a Clark-type microelectrode; (4)the activitiy of the mitochondrial succinate dehydrogenase(SDH) was detected by colorimetry; (5) the mitochondrial membrane fluidity(MMF) was measured by fluorescence polariative method; 3. the mitochondrial ultrastructure changes was observed by transmission electron microscopy (TEM) at 1d and 7d after injection; 4.the expression of ATPase-6 gene in mitochondria was detected by RT-PCR. Results: At 12h after injection, the RCR, the MMF and SDH of mitochondria kept at higher leves (P>0.05). The RCR and the membrane fluidity began to decrease at 1d; and the SDH decreased at 3d(P<0.05).At 7d,they all decreased markedly(P<0.01). The mitochondrial ultrastructur in the tissue around the hematoma only milder changed at 1d;and damaged severely at the 7d. The expression of ATPase-6 gene of mitochondria decreased even more later. Not until 7d, it decreased markedly (P<0.01).Conlusion: 1.The mitochondrial function wasn't changed significantly in earlier, and decreased markedly in later in the tissue around the hematoma; 2.the mitochondria ultrastructure was lesioned slightly in earlier, but destroyed severely in later; 3.the expression of the ATPase-6 gene was not changed markedly in earlier, but declined obviously in later. 4.In ealier stage of ICH, the mitochondrial function and structure might keep in generally normal levels,which offer an important "time window" for the therapy of intracerebral hemorrhage; otherwise, it is perhaps related with the pathophysiology of cell apoptosis after ICH.
|
PDF Full Text Request