[Effects of alpha lipoic acid on hypothalamus-pituitary-adrenal axis in rats].
OBJECTIVE
To study the functional and ultramicrostructural effects of alpha lipoic acid on hypothalamus-pituitary-adrenal (HPA) axis in normal and diabetic rats.


METHODS
Using radioimmunoassay we observed the effects of three doses (1, 20, and 100 mg/kg) of alpha lipoic acid injected intraperitoneally for 3 weeks on the plasma levels of CRH, ACTH and COR in normal and diabetic rats. The ultramicrostructural changes of the hypophysis and pituitary gland after alpha lipoic acid treatment were observed under transmission electron microscope.


RESULTS
Compared with the control group, CRH level in lipoicin-treated normal and diabetic rats was significantly reduced (P<0.05). ACTH level of the 3 lipoicin doses groups of normal rats decreased, and a significant reduction occurred in medium-dose lipoicin group of diabetic rats (P<0.05). COR level showed the same changes as CRH level in normal rats, but decreased significantly in high- and medium-dose lipoicin groups of diabetic rats. Lipoicin treatment produced no apparent effect on the ultramicrostructures of the hypophysis and pituitary gland cells, which were the targets of diabetic lesions with low metabolism functions. Lipoicin treatment obviously enhanced the hypophysis and pituitary gland cell metabolism function to resist diabetic oxidative stress.


CONCLUSIONS
Lipoicin can inhibit the HPA axis directly or indirectly in normal and diabetic rats.
Bu
Le
L
Department of Endocrinology, Changzheng Hospital, Shanghai 200003, China.
Liu
Zhi-min
ZM
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000473:pathology / Q000503:physiopathology; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D008297:Male; D010913:Pituitary-Adrenal System / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000502:physiology; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D008063:Thioctic Acid / Q000494:pharmacology*; D014463:Ultrasonography
D008063:Thioctic Acid