N-calcium channel knockout animal
A non-human animal in which a gene coding for the N-type calcium channel is disrupted to lack functional N-type calcium channel, and a method for screening for a substance having a pharmacological action on blood pressure control, transmission of pain, blood sugar level control and so forth by using the animal.
1. A transgenic mouse in which a gene coding for the α 1B subunit of the N-type calcium channel is disrupted so that the mouse lacks the functional α 1B subunit of the N-type calcium channel, wherein said disruption results in an increased heart rate and blood pressure, decreased transmission of second phase pain or decreased insulin and glucose levels after feeding.
2. The transgenic mouse according to claim 1 , wherein the gene comprises DNA defined in the following (a) or (b):
(a) DNA which comprises the nucleotide sequence of SEQ ID NO: 1;
(b) DNA which hybridizes with DNA comprising the nucleotide sequence of SEQ ID NO: 1 under a stringent condition of hybridization at 65° C. in 4×SSC and subsequent washing at 65° C. in 0.1×SSC for 1 hour and codes for the functional α 1B subunit of the N-type calcium channel.
3. A method for screening for a substance having a pharmacological action, which comprises a step of determining pharmacological action of the substance by the method of (a) or (b):
(a) a method which comprises steps of administering a substance to the transgenic mouse as defined in claim 1 and determining the pharmacological action of the substance, or
(b) a method which comprises steps of administering a substance to the transgenic mouse as defined in claim 1 and a wild-type mouse, and comparing the pharmacological actions of the substance on the transgenic mouse and the wild-type mouse to determine the pharmacological action of the substance,
wherein the pharmacological action is an action for lowering blood pressure, an analgesic action, or an action for lowering blood sugar level.
4. A method for manufacturing a pharmaceutical composition, which comprises steps of screening for a substance having a pharmacological action by the method as defined in claim 3 to obtain a substance having an action for lowering blood pressure an analgesic action, or an action for lowering blood sugar level, and mixing the obtained substance with a pharmaceutically acceptable carrier to manufacture a pharmaceutical composition comprising the obtained substance as an active ingredient.
5. The method according to claim 3 , wherein the pharmacological action is an action for lowering blood pressure.
6. The method according to claim 3 , wherein the pharmacological action is an analgesic action.
7. The method according to claim 3 , wherein the pharmacological action is an action for lowering blood sugar level.