Effect of acute hypoxic shock on the rat brain morphology and tripeptidyl peptidase I activity.
Hypoxic events are known to cause substantial damage to the hippocampus, cerebellum and striatum. The impact of hypoxic shock on other brain parts is not sufficiently studied. Recent studies show that tripeptidyl peptidase I (TPPI) activity in fish is altered after a hypoxic stress pointing out at a possible enzyme involvement in response to hypoxia. Similar studies are not performed in mammals. In this work, the effect of sodium nitrite-induced acute hypoxic shock on the rat brain was studied at different post-treatment periods. Morphological changes in cerebral cortex, cerebellum, medulla oblongata, thalamus, mesencephalon and pons were assessed using silver-copper impregnation for neurodegeneration. TPPI activity was biochemically assayed and localized by enzyme histochemistry. Although less vulnerable to oxidative stress, the studied brain areas showed different histopathological changes, such as neuronal loss and tissue vacuolization, dilatation of the smallest capillaries and impairment of neuronal processes. TPPI activity was strictly regulated following the hypoxic stress. It was found to increase 12-24h post-treatment, then decreased followed by a slow process of recovery. The enzyme histochemistry revealed a temporary enzyme deficiency in all types of neurons. These findings indicate a possible involvement of the enzyme in rat brain response to hypoxic stress.
Department of Experimental Morphology, Institute of Experimental Morphology, Pathology and Anthropology with Museum-Bulgarian Academy of Sciences (IEMPAM-BAS), Sofia 1113, Bulgaria. Electronic address: emiliapetrova@abv.bg.
Emilia B
EB
Petrova
Department of Experimental Morphology, Institute of Experimental Morphology, Pathology and Anthropology with Museum-Bulgarian Academy of Sciences (IEMPAM-BAS), Sofia 1113, Bulgaria. Electronic address: mashadim@abv.bg.
Mashenka B
MB
Dimitrova
Department of Medical Chemistry and Biochemistry, Medical University, Sofia 1431, Bulgaria. Electronic address: ivayloi@abv.bg.
Ivaylo P
IP
Ivanov
Department of Experimental Morphology, Institute of Experimental Morphology, Pathology and Anthropology with Museum-Bulgarian Academy of Sciences (IEMPAM-BAS), Sofia 1113, Bulgaria. Electronic address: velichka_pavlova@abv.bg.
Velichka G
VG
Pavlova
Faculty of Biology, Sofia University "St. Kl. Ohridsky", Sofia 1164, Bulgaria. Electronic address: dimitrova.stella76@gmail.com.
Stella G
SG
Dimitrova
Department of Experimental Morphology, Institute of Experimental Morphology, Pathology and Anthropology with Museum-Bulgarian Academy of Sciences (IEMPAM-BAS), Sofia 1113, Bulgaria. Electronic address: dkadiysky@yahoo.com.
Dimitar S
DS
Kadiysky
D000626:Aminopeptidases / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000098:blood supply / Q000166:cytology / Q000201:enzymology*; D015687:Cell Hypoxia; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000378:metabolism*; D008297:Male; D055806:Microvessels / Q000033:anatomy & histology; D009928:Organ Specificity; D017208:Rats, Wistar; D057057:Serine Proteases / Q000378:metabolism*; D000091346:Tripeptidyl-Peptidase 1
C000717269:Tpp1 protein, rat; D000091346:Tripeptidyl-Peptidase 1; D057057:Serine Proteases; D000626:Aminopeptidases; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases
Central nervous system; Hypoxia; Neurodegeneration; Silver-copper impregnation; Sodium nitrite; Tripeptidyl peptidase I