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Effects of early-onset hypothyroidism on gene expression in the developing rat cerebellum
P3-42 EFFECTS OF E A R L Y - O N S E T HYPOTHYROIDISM
ON GENE EXPRESSION IN THE D E V E L O P I N G RAT
CEREBELLUM. N. Koibuchi 1, S. Matsuzaki 2, K. Ichimura 2, H. Ohtake 1, S. Yamaoka 1 1) Department of Physiology and 2) Biochemistry, Dokkyo University School of Medicine, Mibu, Tochigi 321-02, Japan. A variety of functional, morphological, and biochemical deficits have been described in the brains of animals rendered hypothyroid at birth or earlier in development. However, molecular mechanisms mediating these changes have not been fully understood yet. The aim of this study is to identify the thyroid hormone responsive gene in the newborn rat cerebellum. Pregnant rats received 0.05 % methimazole in drinking water from 15th day of pregnancy. Fifteen days after birth, their pups were sacrificed by decapitation. Control pups whose mothers received normal water were sacrificed simultaneously.
Their cerebellum was then dissected out to extract poly (A) RNA.
constructed using poly (A) RNA of the control animal.
A kgt 10 cDNA library was
Differential plaque screening was then performed using
radiolabelled antisense cDNAs synthesized from the control or methimazole-treated (hypothyroid) rat cerebellar poly (A) RNA. Several clones whose expressions were decreased in the hypothyroid rat were isolated and their DNA sequences were determined. A m o n g them, 4 clones were homologous to the mitochondrial gene, named cytochrome c oxidase subunit I (COX I). We then did in situ hybridization histochemistry to detect which subset of cells showed a change in COX I gene expression.
Radiolabelled RNA probe was transcribed from a 310 base pair COX I cDNA fragment and
hybridized with a cryostat sections obtained from the control or hypothyroid animals. A greater hybridization signal was detected from cells located in the molecular layer. Although no marked difference in the level of COX I m R N A was detected, the distribution of the cells which strongly express COX I gene was different between the control and hypothyroid animal. These results indicate that thyroid hormone influences the expression of COX I gene in the newborn rat cerebellum.
P3-43 A NEW CLASS OF PATHOLOGICAL PROCESS WITH DYSTROPHIC CHANGES OF PROTEIN STRUCTURES. V.Ulzibat, S.Shishov, I.Nazarov, A.Vatorinov, V.Yershov. A.Tregubov. APPLIED MEDICINE RESEARCH CENTER OF ORIGINAL METHODS Among a great number of pathologic changes affecting the somatic state of a body the diseases resulting from dystrophya of protein structure are studied very little. We consider it necessary to single them out as a separate class. We think that the body of all Mammalia has three principle protein systems: connective tissue of muscular system , protein system of blood, hematogenetic and endocrinic organs, and protein system of nervous tissue. The functional disarrangement of this or that protein system dominates depending on the lesion of corresponding protein structure. For instance with mass death of myofibrillae the clinical picture of fibromyalgia (our term Myofibrillosis) is developing. The mass of dead protein increasing the new protein structures of the nervous system with the background of autoimmune conflict are involved into pathologic process, i.e. the syndrome of mutual burden, is developing. We suggest that these pathologic processes should be named proteinosises. Specially we mark out congenital Proteinosises (the s o - c a l l e d Infantile Cerebral Paralysis) and assumed ones - fibromyalgia (myoflbriillosis). Proteinosis can be causal by various factors but more often it is the result of serious viral infections and serious illness of endocrinic organs. Proteinosises develop according to the following scheme: it starts with the death of small structures of the given protein system, then their lysis takes place and after that the process of substitution of the dead segments by scar tissue with the background of increasing autoimmune reaction begins. We consider it to be necessary to enlarge the study of early diagnosis, treatment and prophylaxis of the proteinosises.
503
ON GENE EXPRESSION IN THE D E V E L O P I N G RAT
CEREBELLUM. N. Koibuchi 1, S. Matsuzaki 2, K. Ichimura 2, H. Ohtake 1, S. Yamaoka 1 1) Department of Physiology and 2) Biochemistry, Dokkyo University School of Medicine, Mibu, Tochigi 321-02, Japan. A variety of functional, morphological, and biochemical deficits have been described in the brains of animals rendered hypothyroid at birth or earlier in development. However, molecular mechanisms mediating these changes have not been fully understood yet. The aim of this study is to identify the thyroid hormone responsive gene in the newborn rat cerebellum. Pregnant rats received 0.05 % methimazole in drinking water from 15th day of pregnancy. Fifteen days after birth, their pups were sacrificed by decapitation. Control pups whose mothers received normal water were sacrificed simultaneously.
Their cerebellum was then dissected out to extract poly (A) RNA.
constructed using poly (A) RNA of the control animal.
A kgt 10 cDNA library was
Differential plaque screening was then performed using
radiolabelled antisense cDNAs synthesized from the control or methimazole-treated (hypothyroid) rat cerebellar poly (A) RNA. Several clones whose expressions were decreased in the hypothyroid rat were isolated and their DNA sequences were determined. A m o n g them, 4 clones were homologous to the mitochondrial gene, named cytochrome c oxidase subunit I (COX I). We then did in situ hybridization histochemistry to detect which subset of cells showed a change in COX I gene expression.
Radiolabelled RNA probe was transcribed from a 310 base pair COX I cDNA fragment and
hybridized with a cryostat sections obtained from the control or hypothyroid animals. A greater hybridization signal was detected from cells located in the molecular layer. Although no marked difference in the level of COX I m R N A was detected, the distribution of the cells which strongly express COX I gene was different between the control and hypothyroid animal. These results indicate that thyroid hormone influences the expression of COX I gene in the newborn rat cerebellum.
P3-43 A NEW CLASS OF PATHOLOGICAL PROCESS WITH DYSTROPHIC CHANGES OF PROTEIN STRUCTURES. V.Ulzibat, S.Shishov, I.Nazarov, A.Vatorinov, V.Yershov. A.Tregubov. APPLIED MEDICINE RESEARCH CENTER OF ORIGINAL METHODS Among a great number of pathologic changes affecting the somatic state of a body the diseases resulting from dystrophya of protein structure are studied very little. We consider it necessary to single them out as a separate class. We think that the body of all Mammalia has three principle protein systems: connective tissue of muscular system , protein system of blood, hematogenetic and endocrinic organs, and protein system of nervous tissue. The functional disarrangement of this or that protein system dominates depending on the lesion of corresponding protein structure. For instance with mass death of myofibrillae the clinical picture of fibromyalgia (our term Myofibrillosis) is developing. The mass of dead protein increasing the new protein structures of the nervous system with the background of autoimmune conflict are involved into pathologic process, i.e. the syndrome of mutual burden, is developing. We suggest that these pathologic processes should be named proteinosises. Specially we mark out congenital Proteinosises (the s o - c a l l e d Infantile Cerebral Paralysis) and assumed ones - fibromyalgia (myoflbriillosis). Proteinosis can be causal by various factors but more often it is the result of serious viral infections and serious illness of endocrinic organs. Proteinosises develop according to the following scheme: it starts with the death of small structures of the given protein system, then their lysis takes place and after that the process of substitution of the dead segments by scar tissue with the background of increasing autoimmune reaction begins. We consider it to be necessary to enlarge the study of early diagnosis, treatment and prophylaxis of the proteinosises.
503