title: Serum inhibin is inversely correlated with serum FSH levels in adult men.
abstract: Serum inhibin, FSH, and testosterone levels were measured by radioimmunoassay in 36 normal human males, aged 8 to 63 years. Inhibin and FSH levels rose during 8 to 17 years to reach adult values. At these ages there is a significant direct linear correlation between serum FSH and inhibin levels (r = 0.81, p less than 0.01), whereas in adulthood the relationship between serum FSH and inhibin levels was significant inverse (r = -0.70, p less than 0.01). No correlation was found between serum testosterone and FSH (r = -0.18, p:NS) or between serum testosterone and inhibin (r = 0.14, p:NS). In senescence there is a significant decrease in the serum inhibin levels (r = -0.53, p less than 0.05). These findings suggest that negative feedback is established once serum inhibin has reached adult values, and that in physiologic conditions inhibin plays a greater role than testosterone in the negative feedback regulation of FSH.
authors.affiliation: Instituto de Investigaciones de la Altura-Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: R
authors.initials: R
authors.lastname: Guerra-Garcia
authors.forename: J
authors.initials: J
authors.lastname: Franco
authors.forename: G F
authors.initials: GF
authors.lastname: Gonzales
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006801:Humans; D007265:Inhibins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D013739:Testosterone / Q000097:blood
chemical_list: D013739:Testosterone; D007265:Inhibins; D005640:Follicle Stimulating Hormone