AVAILABILITY OF SERUM FROM CLOTTED RAT BLOOD ON EMBRYOGENESIS

MIYUKI KATOH, REIKO KIMURA AND RYUUJIROU SHOJI
Department of Embryology, Institute for Developmental Research, Aichi Human Service Center, Kamiya-cho, Kasugai, Aichi 480-03, Japan

Original:AATEX 4(3/4):93-99

Abstract
There are two ways to isolate serum from blood. One is to isolate so-called IC-serum by centrifuging immediately after drawing blood. Another is to isolate serum (called DC-serum) from blood 18 hours after clotting. IC-rat serum has been used as the most beneficial medium for in vitro culture of rat whole embryos. Rat embryos are known to develop well and normally in the IC-serum, but not with the DC-serum. In our experiments, serum was isolated from rat blood I h after clotting. This serum (3-h-DC-serum) seemed to be one of the DC-sera. Embryogenesis in whole embryo culture with 3-h-DC-serum occurred as normally as it did in the IC-serum. Development of rat embryos cultured in 50% 3-h-DC-serum was compared with that in 50% IC-serum, knowing that all embryos cultured in 30-100% IC-sera diluted with Dulbecco’s Modified Eagle medium revealed normal development. As a result, it was found that the promoting effect of 3-h-DC-serum on embryogenesis was indistinguishable from that of the IC-serum. Moreover, hemolysis of rat serum within 5% was also found not to affect embryogenesis.

TOXICOLOGICAL AND PHARMACOLOGICAL EVALUATION OF XANTHINE DERIVATIVES USING CHICK EMBRYOS AS THE ALTERNATIVE EXPERIMENTAL METHOD

HIROYUKI MIYAZAKI, TAKASHI SUGIYAMA AND HIDEYO SHIMADA
Division of Pathophysiology, Center for Clinical Pharmacy and Clinical Sciences, School of Pharmaceutical Sciences, Kitasato University, 9-1, Shirokane 5-chome, Minato-ku, Tokyo 108-8641 Japan

Original:AATEX 4(3/4):101-109

Abstract
The toxicological and pharmacological effects of xanthine derivatives, caffeine, theophylline and then bromine were investigated using chick embryos. The drugs were each injected into the air sac of fertile eggs on the 2, 5, 8 or 16th day of incubation and LD50 values were determined from the number of the dead embryos on the 18th day of incubation. LD50 values of drugs were more higher in the late stages of incubation. The strength of toxicity was arranged in order of theobromine>caffeine>theophylline, regardless the injection ages. The LD50 values of these drugs in ICR mice i.v. route were also determined and compared with those in chick embryos. However, no good correlation was obtained from LD50 values between two animals.
Furthermore, we evaluated the effects of these drugs on the electrocardiogram tracings of chick embryos. When xanthine derivatives were injected into the air sac of fertile eggs on the 16th day of incubation, theophylline and caffeine increased as that of mammals. The effect of theobromine was different in comparison with that of other drugs.
In conclusion, lethal toxicity of xanthine derivatives in mammals which may be due to a central nervous systemic action could not predict from data of chick embryos. The heart rate of the 16th-day embryos were increased by pharmacological action which may be due to peripheral action of xanthine derivatives. From these facts, chick embryos may be very useful as an alternative animal to obtain the pharmacological effects of cardiovascular drugs.

Key words: xanthine derivatives, electrocardiogram, chick embryo, lethal toxicity, arrhythmia.

PROCEEDINGS OF 10TH ANNUAL MEETING OF JAPANESE SOCIETY FOR ANIMAL TESTING AND EXPERIMENTS AT TOKYO (DEC.5-6, 1996)

Proceedings:AATEX 4(3/4):111-155