In vitro effects of mammalian leptin, neuropeptide-Y, beta-endorphin and galanin on transcript levels of thyrotropin beta and common alpha subunit mRNAs in the pituitary of bighead carp (aristichthys nobilis).
Thyrotropin (thyroid stimulating hormone, TSH) is a member of the pituitary glycoprotein hormones, consisting of two dissimilar subunits, alpha and beta. The two subunits are produced by different genes and are regulated independently. We have previously cloned a TSHbeta cDNA from bighead carp pituitary and investigated its gene regulation. We report here the direct effects of mammalian TSH-releasing hormone (TRH), leptin, neuropeptide-Y (NPY), beta-endorphin and galanin on mRNA levels of both TSHbeta and alpha-subunits in the pituitary of bighead carp in vitro. The dispersed pituitary cells of bighead carp were incubated at 25 degrees C for 6 h with different doses of these factors. The relative mRNA levels of TSHbeta and alpha-subunits were estimated by traditional polymerase chain reaction (PCR) analysis and fluorescence real-time PCR analysis. The results revealed that mammalian TRH, leptin and beta-endorphin produced dose-dependent stimulatory effects on mRNA levels of both TSHbeta and alpha-subunits while thyroxine (T4) and mammalian galanin suppressed mRNA levels of both TSHbeta and alpha-subunits. NPY suppressed TSHbeta mRNA level, but stimulated alpha-subunit mRNA level. This study has demonstrated that mammalian TRH, leptin, NPY, beta-endorphin and galanin were active in modulating the steady-state mRNA levels of TSHbeta and alpha-subunits of bighead carp pituitary in vitro. The results suggest that endogenous TRH, leptin, NPY, beta-endorphin and galanin may modulate transcript levels of TSHbeta and alpha-subunits in pituitary of bighead carp.
Chowdhury
I
I
Institute of Zoology, Academia Sinica, Endocrinology Laboratory, No. 128, Sec. 2, Academic Rd., Nan., Taipei, Taiwan 115, ROC.
Chien
J T
JT
Chatterjee
A
A
Yu
J Y L
JY
D000818:Animals; D002347:Carps / Q000235:genetics*; D018929:Cell Culture Techniques; D005260:Female; D005453:Fluorescence; D019004:Galanin / Q000494:pharmacology*; D015292:Glycoprotein Hormones, alpha Subunit / Q000235:genetics; D020738:Leptin / Q000494:pharmacology*; D008322:Mammals / Q000378:metabolism; D009478:Neuropeptide Y / Q000494:pharmacology*; D010902:Pituitary Gland / Q000187:drug effects* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013972:Thyrotropin / Q000235:genetics*; D037322:Thyrotropin, beta Subunit / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics; D001615:beta-Endorphin / Q000494:pharmacology*
D015292:Glycoprotein Hormones, alpha Subunit; D020738:Leptin; D009478:Neuropeptide Y; D012333:RNA, Messenger; D037322:Thyrotropin, beta Subunit; D001615:beta-Endorphin; D019004:Galanin; D013972:Thyrotropin