Increased circulating levels of immunoreactive beta-endorphin in polycystic ovary syndrome is not caused by increased pituitary secretion.
OBJECTIVE
Our purpose was to investigate the source and role of elevated levels of immunoreactive beta-endorphin in polycystic ovary syndrome. We wished to determine whether immunoreactive beta-endorphin secretion in patients with polycystic ovary syndrome is influenced by body weight and whether the pituitary release of immunoreactive beta-endorphin with corticotropin-releasing hormone is related to luteinizing hormone levels or adrenal androgen secretion.


METHODS
Eighteen patients with polycystic ovary syndrome and 10 ovulatory controls were studied. Each subject received 1 microgram/kg intravenous corticotropin-releasing hormone and an oral glucose tolerance test on alternate days. Levels of plasma immunoreactive beta-endorphin, corticotropin, luteinizing hormone, cortisol, adrenal androgens, and insulin were measured.


RESULTS
Although immunoreactive beta-endorphin levels were elevated in patients with polycystic ovary syndrome (p < 0.01), incremental responses after corticotropin-releasing hormone were similar to controls and were not influenced by body weight. Serum luteinizing hormone levels were not affected by corticotropin-releasing hormone and did not correlate with immunoreactive beta-endorphin levels. Adrenal androgen responses after corticotropin-releasing hormone were increased in patients with polycystic ovary syndrome (p < 0.01) but were not correlated with immunoreactive beta-endorphin secretion. After oral glucose was given, elevated fasting insulin levels increased significantly in patients with polycystic ovary syndrome (p < 0.01), as did immunoreactive beta-endorphin levels (p < 0.05). The increases in insulin and immunoreactive beta-endorphin levels were correlated (p < 0.05).


CONCLUSIONS
Pituitary secretion of immunoreactive beta-endorphin is normal in patients with polycystic ovary syndrome, and pancreatic secretion appears to be increased. Corticotropin-releasing hormone does not influence luteinizing hormone levels, and adrenal androgen sensitivity is not influenced by immunoreactive beta-endorphin secretion.
Carmina
E
E
Cattedra di Endocrinologia, Universita di Palermo, Italy.
Ditkoff
E C
EC
Malizia
G
G
Vijod
A G
AG
Janni
A
A
Lobo
R A
RA
D000328:Adult; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D010902:Pituitary Gland / Q000378:metabolism*; D011085:Polycystic Ovary Syndrome / Q000097:blood*; D011863:Radioimmunoassay; D012016:Reference Values; D001615:beta-Endorphin / Q000097:blood*
D001615:beta-Endorphin; D007986:Luteinizing Hormone; D003346:Corticotropin-Releasing Hormone