1997 Fiscal Year Final Research Report Summary
Effect of dihydrotestosterone on cardiovascular system
| Project/Area Number |
08670500
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Legal medicine
|
|---|
| Research Institution | Showa University |
|---|
Principal Investigator |
TSUNODA Kenji Showa University, School of Medicine, associate professor, 医学部, 助教授 (40095906)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
DOGE Koichi Showa University, School of Medicine, lecturer, 医学部, 講師 (60188844)
|
|---|
| Project Period (FY) |
1996 – 1997
|
| Keywords | dihydrotestosterone / cardiovascular system / cardiac hypertrophy / hypotension / hyperventilation / obese rats / plasma lipids / LDL-C |
|---|
| Research Abstract |
We conducted a study to evaluate the effects of 5 alpha-dihydrotestosterone (DHT) on the cardiovascular system, including the supplementary respiratory effects, and circulating lipids using normal and obese groups of Wistar castrated male rats. The hormone-treated normal rats had a significantly greater weight of the right ventricular wall and atria and body weight ratio when compared to the controls. Cardiac function estimated from the parametric vaue multiplied heart rate by carotid maximal systolic pressure was significantly lowered in the hormone-treated rats. However, no difference in the right ventricular action between the hormone-treated and control rats was found. In respiratory parameters, expired CO_2 gas decreased significantly in the hormone-treated rats. On the other hand, the hormone-treated obese rats showed a significantly greater weight of the heart and body weight ratio. This was due to the significant gain of the ventricular septum weight, in addition to the weight
… More
gains of the right ventricular wall and atria. Cardiac function of the hormone-treated obese rats was significantly lower than that of the controls and lower than that of normal rats. Significant increase in respiratory rate and decrease in expired CO_2 gas were seen in the hormone-treated rats. Therefore, these results demonstrate that the hormone had hypertrophic effects mainly on the right ventricle or atria and suppressive effects on cardiovascular function or promotive effects on respiratory ventilation, with both of the latter effects enhanced comparatively in obese rats.
Concerning plasma lipids, DHT administration produced a significantly low level of TC in the normal and obese groups, when compared to the controls. A significant low level of HDL-C and a high level of LDL-C were seen in both groups. No difference was observed in the effect of DHT on HDL-C between the groups, as seen in the case of TC.However, the effect on the LDL-C level was greater in obese than in normal males. The potency of the hormone was 56.8% for the former and 38.6% for the latter. For triglycerides, an increase in the plasma level by DHT administration was found in both groups, however, the potency was lower in obese compared to the normal males (63.3% and 86.7%, respectively). In respect of the significant influence of exogenous DHT on circulating LDL-C under an obese state, the hormone may have a more adverse effect on the cardiovascular system. Less
|
