title: Role of the serotonergic system in the control of gonadotropin secretion in prepubertal male rats.
abstract: To analyze the role of brain serotonin in the control of gonadotropin secretion in prepubertal males, serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) concentrations were studied at different ages after administration of 5-hydroxytryptophan (5-HTP), a precursor of serotonin synthesis, alone or in combination with fluoxetine, a specific inhibitor of serotonin uptake; 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), a serotonin 1A agonist; or D,L-p-chlorophenylalanine methyl ester hydrochloride (PCPA), an inhibitor of serotonin synthesis. Also, serum gonadotropin concentrations were measured in castrated males implanted with silastic capsules containing testosterone or 5 alpha-androstane-3 alpha, 17 beta-diol (alpha-diol). We found that: (i) the blockade of the serotoninergic system after PCPA administration did not modify basal gonadotropin secretion but did strongly reduce the response to orchidectomy; (ii) a stimulatory effect of 5-HTP on FSH secretion was only observed in intact males at the age of 8 days; (iii) the serotonin 1A agonist 8-OH-DPAT did not change serum gonadotropin concentrations; (iv) 5-HTP increased serum FSH and LH concentrations in 16-day-old castrated males; (v) FSH and LH serum concentrations decreased after 5-HTP in castrated animals implanted with testosterone, whereas castrated animals implanted with alpha-diol showed, like the intact males, a lack of response to 5-HTP.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Córdoba, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Pinilla
authors.forename: A
authors.initials: A
authors.lastname: Ranchal
authors.forename: R
authors.initials: R
authors.lastname: Aguilar
authors.forename: E
authors.initials: E
authors.lastname: Aguilar
mesh_terms: D006916:5-Hydroxytryptophan / Q000494:pharmacology; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D010134:Fenclonine / Q000031:analogs & derivatives / Q000494:pharmacology; D005473:Fluoxetine / Q000494:pharmacology; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000378:metabolism*; D008297:Male; D009919:Orchiectomy; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000502:physiology; D012701:Serotonin / Q000502:physiology*; D012741:Sexual Maturation; D013739:Testosterone / Q000494:pharmacology
chemical_list: D011985:Receptors, Serotonin; D005473:Fluoxetine; C020261:4-chlorophenylalanine methyl ester; D012701:Serotonin; D013739:Testosterone; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D006916:5-Hydroxytryptophan; D010134:Fenclonine