Effects of morphine on the pituitary-thyroid axis: morphological and analytical studies.
The morphology of the TSH-producing pituitary cells and the thyroid gland, and plasma TSH, T3 and T4 hormone levels, were studied in normal rats, in rats treated with 10 micrograms morphine (M) and in M-treated animals pretreated with naloxone (Nx) (10 mg/kg). Morphological changes in the pituitary TSH cells and thyroid cells of M-treated animals were minimal and were not modified by Nx pretreatment. Plasma TSH levels in M-treated animals showed a significant decrease (P less than 0.05), which was not blocked by Nx pretreatment. No significant changes in plasma T3 or T4 levels were found in either experimental group.
del Valle-Soto
M E
ME
Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, Spain.
Iglesias
L
L
Calzada
B
B
Vega
J A
JA
Hernandez
L C
LC
Pérez-Casas
A
A
D000818:Animals; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone; D010902:Pituitary Gland / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013961:Thyroid Gland / Q000187:drug effects*; D013972:Thyrotropin / Q000037:antagonists & inhibitors*
D009270:Naloxone; D009020:Morphine; D013972:Thyrotropin