Aging is associated with changes in allopregnanolone concentrations in brain, endocrine glands and serum in male rats.
OBJECTIVE
Allopregnanolone is a potent neuroactive steroid hormone produced in the brain and in peripheral endocrine glands. The present study investigated possible age-related variations in allopregnanolone content in brain areas, endocrine glands and serum of male rats.


METHODS
Wistar male rats were categorized into 5 groups (6 rats in each) according to age: 6, 12, 16, 18 and 20 months respectively.


METHODS
Allopregnanolone content in acidic homogenates of brain cortex, hypothalamus, pituitary, adrenals and gonads was measured by a specific radioimmunoassay. Serum allopregnanolone, corticosterone and testosterone were also assayed by radioimmunoassay.


RESULTS
Brain cortex allopregnanolone content decreased significantly with age, while hypothalamic allopregnanolone content remained constant until 18 months and increased significantly at 20 months. Pituitary content showed a significant age-related reduction. Adrenal allopregnanolone content remained constant until 18 months, and was significantly higher at 20 months. Testis and serum allopregnanolone contents showed significant age-related increases. Serum testosterone levels showed an age-related decrease, while no age-related variation in serum corticosterone was found.


CONCLUSIONS
The present study showed a significant impact of aging on allopregnanolone contents in brain, endocrine glands and serum, showing an age-related decrease in brain cortex and pituitary, and an age-related increase in testes, adrenals and serum.
Bernardi
F
F
Department of Obstetrics and Gynecology, University of Pisa, Italy.
Salvestroni
C
C
Casarosa
E
E
Nappi
R E
RE
Lanzone
A
A
Luisi
S
S
Purdy
R H
RH
Petraglia
F
F
Genazzani
A R
AR
D000311:Adrenal Glands / Q000737:chemistry; D000375:Aging / Q000097:blood / Q000502:physiology*; D000818:Animals; D001923:Brain Chemistry / Q000502:physiology*; D002540:Cerebral Cortex / Q000737:chemistry; D015331:Cohort Studies; D003345:Corticosterone / Q000097:blood; D003429:Cross Reactions; D004702:Endocrine Glands / Q000737:chemistry*; D007031:Hypothalamus / Q000737:chemistry; D007106:Immune Sera / Q000276:immunology; D008297:Male; D010902:Pituitary Gland / Q000737:chemistry; D011280:Pregnanolone / Q000032:analysis* / Q000097:blood; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D012756:Sheep; D013737:Testis / Q000737:chemistry*; D013739:Testosterone / Q000097:blood
D007106:Immune Sera; D013739:Testosterone; D011280:Pregnanolone; D003345:Corticosterone