Etiology of congenital deformity may be found in heredity, irradiation, infection, endocrine dysfunction, ingestion of some chemical substances, malnutrition of mother, stress and mechanical effects during delivery.
Other factors may also be responsible for production of deformity. The author studied the teratogenic effect of emotional stress in rats.
Experimental Method:
Adult Winster rats weighing about 200 grs. were used. Two female rats were kept in a box with a male rat. After confirming pregnancy female rats were sacrificed at different periods of pregnancy. The rats were divided into the following groups: 19-day sacrifice group:
Control Group
Ao. represents a group for control,
Bo. represents a group treated with trypan blue.; 1% solution of trypan blue was injected 1 cc/100 gr. body weight, on the 8th day of pregnancy.
Co. includes a group which received 40, 000 IU. of vitamine A subcutaneously per 100 gr.
Stress Group
As. represents a group subjected to emotional stress.
Bs. indicates a group in which stress was given after injection with trypan blue.
Cs. represents a group in which stress was given after vitamine A injection.
Stress Group
As. represents a group subjected to emotional stress.
Bs. indicates a group in which stress was given after injection with trypan blue.
Cs. represents a group in which stress was given after vitamine A injection. of body weight on the 8th day of pregnancy.
15-day sacrifice group:
Do. is a group for control.
Ds. includes those in which emotional stress was given.
Ds. indicates a group which received both stress and vitamine A injection.
The stress was given by means of repeated flashes of light, loud noise and electric current for 6 hours a day from the 9th day to 15th day of pregnancy.
A half of the animals were sacrificed on the 15th day and the others on the 19th day of pregnancy in order to examine the fetuses and placentas.
The mother rats were also examined for numbers of eosinophiles and change in body weight during pregnancy.
Hypophysis and adrenal glands were weighed and examined histolo gically after they were sacrificed.
Results:
1. As. group showed a decrease in number of eosinophiles, however, no macroscopic or microscopic anomaly was found. Fetal death has significantly increased in comparison with Ao. group.
2. Anomaly in Bs. group was found in 3.7% of the population, which was not a significant increase as compared with the control group. significant difference was observed between trypan blue and stress in the production of deformities.
3. Co. group included deformity in 29.1% and Cs. group 69.1%, both of which were significantly increased. This fact may indicate an augmentative effect when vitamine A and stress combined.
No significant difference was noted in the number of fetal death.
The most frequent deformity was cleft palats, followed by deformity of the auricle, eye, micrognathia, separation of the mandible and separation of the tongue.
4. Histological examination confirmed the macroscopic observation.
5. Histological examination of the placenta revealed more congestion in stress groups.
6. Weight of the hypophysis and the adrenal glands showed similar changes in the stress group.
Histological examination of Ds. group showed increased congestion of the hypophysis while of adrenal gland in Cs. group revealed thickening of the adrenal cortex.
7. The author concluded that emotional stress given in certain condition can produce deformity in fetuses.
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