Identification of amino acid transport systems stimulated by FSH in rat testes.
Testes of 12-day-old rats preincubated (90 min) and incubated (60 min) with FSH in Krebs-Ringer bicarbonate buffer (KRB) increased their uptake of [14C]methylaminoisobutyric acid and [14C]aminoisobutyric acid. The hormone was ineffective in sodium-free KRB. Transport of [14C]aminoisobutyric acid in the presence of methylaminoisobutyric acid (MeAIB; 30 mmol/l) was not stimulated by FSH, and uptake of [14C]cycloleucine was not increased by FSH in any of the experimental conditions used. It was concluded that in immature rat testes FSH affects only the sodium-dependent system which permits the transport of MeAIB (transport system A) and has no effect on the sodium-independent system which prefers leucine (system L) or the sodium-dependent system which does not transport MeAIB (system ASC).
D000596:Amino Acids / Q000378:metabolism*; D000621:Aminoisobutyric Acids / Q000378:metabolism; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002250:Carbon Radioisotopes; D003515:Cycloleucine / Q000378:metabolism; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D008297:Male; D009924:Organ Culture Techniques; D051381:Rats; D011919:Rats, Inbred Strains; D013268:Stimulation, Chemical; D013737:Testis / Q000378:metabolism*
D000596:Amino Acids; D000621:Aminoisobutyric Acids; D002250:Carbon Radioisotopes; D003515:Cycloleucine; C100049:2-aminoisobutyric acid; C017911:2-(methylamino)isobutyric acid; D005640:Follicle Stimulating Hormone