The effect of intrathecal injection of dynorphin A (1-17) on second messenger systems of spinal cord relative to behavioral change in rats was studied. Dynorphin A (1-17) 5 ,10 (20nmol) caused dose-dependent flaccid p...The effect of intrathecal injection of dynorphin A (1-17) on second messenger systems of spinal cord relative to behavioral change in rats was studied. Dynorphin A (1-17) 5 ,10 (20nmol) caused dose-dependent flaccid paralysis of hindlimbs. Dynorphin A (1-17) 10, 20 nmol dose-dependently decreased spinal adenylate cyclase (AC) activity, cyclic AMP production, calmodulin (CaM) level and cyclic-nucleotide phosphodiesterase(PDE)activity 10 min after intrathecal injection. They recovered to a varying extent two hours later. Pretreatment with selective κ-opioid receptor antagonist nor-BNI 30 nmol 10 min before dynorphin A (1-17) markedly antagonized the effects of dynorphin A (1-17 ) at 20 nmol on hindlimb paralysis and inhibition of intracellular second messengers. The L-type calcium channel blocker verapamil (100nmol) also played a role in blocking dynorphin neurotoxicity. The NMDA receptor antagonist APV could partially or completely block dynorphin inhibition of CaM level and PDE activity without affecting paralysis and decrease of AC-cAMP level induced by dynorphin A(1-17) 10 min after intrathecal injection.展开更多
1.单项填空1. He made the suggestion a question.A. in a form of B. in form of C. in the form of D. at the form of2. There was always water in the well.A. a plenty of B. great muchC. a large numb...1.单项填空1. He made the suggestion a question.A. in a form of B. in form of C. in the form of D. at the form of2. There was always water in the well.A. a plenty of B. great muchC. a large number of D. plenty of3.I saw villagers working in the fields.A. score of B. scores of C. three scores of D. score4. The foods he ate were rich fat and sugar.A.in B.of C.for D.展开更多
文摘The effect of intrathecal injection of dynorphin A (1-17) on second messenger systems of spinal cord relative to behavioral change in rats was studied. Dynorphin A (1-17) 5 ,10 (20nmol) caused dose-dependent flaccid paralysis of hindlimbs. Dynorphin A (1-17) 10, 20 nmol dose-dependently decreased spinal adenylate cyclase (AC) activity, cyclic AMP production, calmodulin (CaM) level and cyclic-nucleotide phosphodiesterase(PDE)activity 10 min after intrathecal injection. They recovered to a varying extent two hours later. Pretreatment with selective κ-opioid receptor antagonist nor-BNI 30 nmol 10 min before dynorphin A (1-17) markedly antagonized the effects of dynorphin A (1-17 ) at 20 nmol on hindlimb paralysis and inhibition of intracellular second messengers. The L-type calcium channel blocker verapamil (100nmol) also played a role in blocking dynorphin neurotoxicity. The NMDA receptor antagonist APV could partially or completely block dynorphin inhibition of CaM level and PDE activity without affecting paralysis and decrease of AC-cAMP level induced by dynorphin A(1-17) 10 min after intrathecal injection.
文摘1.单项填空1. He made the suggestion a question.A. in a form of B. in form of C. in the form of D. at the form of2. There was always water in the well.A. a plenty of B. great muchC. a large number of D. plenty of3.I saw villagers working in the fields.A. score of B. scores of C. three scores of D. score4. The foods he ate were rich fat and sugar.A.in B.of C.for D.