Ageing and melatonin influence on in vitro gonadotropins and prolactin secretion from pituitary and median eminence.
The effect of ageing and/or melatonin (MEL) on in vitro gonadotropins, luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin (PRL) release and tissue content from pituitary and median eminence (ME) were investigated. Gonadotropins and PRL basal release (I-1) from hemipituitaries of young cyclic-rats was decreased by MEL to levels shown in old acyclic rats. Pituitary tissue content of LH and PRL were not affected by ageing or MEL treatment. However, pituitary FSH tissue content was decreased by ageing and MEL, suggesting a different regulatory mechanism. MEL inhibitory influence on pituitary hormones is mainly exerted on the secretory process. This effect is only exerted in young rats. ME LH and PRL release and content were significantly lower than in pituitary. However, FSH release and content in ME showed values similar to those found in the pituitary. This study confirms that the functional capacities of pituitary gland and ME are maintained during reproductive senescence.
Fernández Alvarez
C
C
Departamento Biología Funcional, Area Fisiología, Facultad de Medicina, Universidad de Oviedo, C/Julian Claveria No. 6, 33006, Oviedo, Spain.
Díaz Rodríguez
E
E
Pazo Vinuesa
D
D
Esquifino Parras
A I
AI
Díaz López
B
B
D000375:Aging / Q000502:physiology*; D000818:Animals; D005260:Female; D006062:Gonadotropins / Q000378:metabolism*; D066298:In Vitro Techniques; D008473:Median Eminence / Q000378:metabolism*; D008550:Melatonin / Q000378:metabolism*; D010902:Pituitary Gland / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D006062:Gonadotropins; D011388:Prolactin; D008550:Melatonin