[Melatonin radioimmunoanalysis: evaluation of the pineal function in hyperprolactinemic male rats and controls].
A sensitive and specific radioimmunoassay for melatonin quantification in rat pineal and biological fluids is described. The assay utilizes a specific antibody and H3-melatonin as tracer. Bound and free fraction were separated by a saturated sulphate ammonium solution. The sensitivity of the method is 9 pg/ml. The intra and interassay variation coefficient were 10.4 and 13.6% respectively. By means of this RIA the content of melatonin in the pineal gland in male rats made hyperprolactinemic on day 30 of life and their respective sham-operated controls has been evaluated. The results showed that the melatonin content measured at 2 a.m. was reduced in the transplanted animals when compared to control group, not only shortly (48 hours) after the transplant operation, but also in the chronic situation; though suggesting that further investigations are necessary to deepen and understand the interrelationships between prolactin and pineal gland and their effect on the hypothalamic-pituitary-gonadal axis.
D000818:Animals; D006066:Gonads / Q000503:physiopathology; D006966:Hyperprolactinemia / Q000503:physiopathology*; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D008297:Male; D008550:Melatonin / Q000032:analysis*; D010870:Pineal Gland / Q000503:physiopathology*; D011388:Prolactin / Q000502:physiology; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
D011388:Prolactin; D008550:Melatonin
Radioinmunoanálisis de melatonina: valoración de la función pineal en ratas macho hiperprolactinémicas y controles.