Abstract:

Abstract: Objective To explore the feasibility of appling the laboratory rabbits in the test for depressor substances of drugs by comparing the differences of depressor response to histamine between the laboratory rabbits and cats. Method The amount of conventional New Zealand rabbits,Japanese white rabbits,Chinchilla rabbits and healthy cats was respectively 6, half male and half female. After anesthetized with pentobarbital sodium, they were injected intravenously with standard histamine solution by a dose of 0. 05—5. 0 μg / kg ( rabbits ) or 0. 05—1. 0 μg / kg ( cats) and Shengmai injection both by a dose of 0. 5 mL / kg and 1. 0 mL / kg. We try firstly to compare the sensitivity, reproducibility and stability of blood pressure of the depressor responses to the standard histamine solution among three stocks of laboratory rabbits. Then the consistency of the result in the sensitivity test for histamine with the requirement of Chinese Pharmacopoeia( ChP) was also compared, and whether was different for histamine and Shengmai injection that induce depressor effects between the laboratory rabbits and cats. Result The sensitivity and reproducibility of the depressor response to histamine in 3 stocks of rabbits were consistent, without any significant differences, but it was easier to inject by the ear margin veins of New Zealand rabbits, with more stable blood pressure during operating. Comparing with cats, the rabbits were not very sensitive to the depressor effect of histamine, its depressor response was only about 1 / 8 of cats, so that the result of histaminesensitivity test did not meet the requirement of ChP. However, Shengmai injection also had the same significant depressor response to all the laboratory rabbits as the cats, which was about 2 / 3 of that of the cats. Conclusion The laboratory rabbits are not sensitive to histamine and not be currently used for the test for depressor substances, but as being sensitive to Shengmai injection, so that the study also demonstrated that histamine had obviously species selectivity on the depressor response of animals.