Proliferation of lamellar whorls in arcuate neurons of the hypothalamus of castrated and morphine-treated male rats.
A comprehensive ultrastructural examination of one cross-sectional level (middle 1/3) of the arcuate nucleus of the hypothalamus (AH) of male rats several weeks after castration or after two weeks of morphine treatment confirmed a marked increased in lamellar whorls of endoplasmic reticulum in AH neurons in each group. A comparable incidence of AH whorls was not detected in rats treated with lactose, those treated for only 1--3 days with morphine, or in those given testosterone plus morphine for 2 weeks. It is postulated that the testosterone deficiency following either castration or chronic morphine treatment stimulated the observed increase in AH whorls. A close correspondence was noted between the distribution within the AH of neurons containing whorls and those reported by others to contain luteinizing hormone releasing hormone (LH-RH). The possibility that whorls may be a marker for hypothalamic neurons which play a role in the LH-RH regulatory system warrants further consideration.
D000818:Animals; D002369:Castration; D004721:Endoplasmic Reticulum / Q000648:ultrastructure*; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009474:Neurons / Q000648:ultrastructure; D051381:Rats; D013739:Testosterone / Q000502:physiology; D013787:Thalamic Nuclei / Q000187:drug effects / Q000648:ultrastructure*
D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D009020:Morphine