Differential expression of the pituitary gonadotropin subunit genes during male rat sexual maturation: reciprocal relationship between hypothalamic pituitary adenylate cyclase-activating polypeptide and follicle-stimulating hormone beta expression.
The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) has been shown to differentially regulate the expression of the gonadotropin subunit genes in cultures of rat pituitary cells. PACAP is expressed within the hypothalamus, and concentrations of PACAP are 2- to 4-fold higher in the portal circulation than in the general circulation. Therefore, PACAP is a candidate regulator of pituitary function. In the present study, we examined the expression of PACAP mRNA within the paraventricular nucleus (PVN) during maturation (Days 20-60) in the male rat and compared this expression to the levels of the gonadotropin subunits, follistatin, and GnRH-receptor mRNAs within the anterior pituitary. Serum concentrations of FSH and LH confirm the established maturational pattern of divergent secretion of LH and FSH. Northern analysis of the gonadotropin subunit mRNAs revealed that FSHbeta expression parallels FSH secretion whereas LHbeta mRNA concentrations do not change during development. Expression of the GnRH receptor in the pituitary parallels that of FSHbeta. In situ hybridization revealed a developmental pattern of PACAP mRNA within the PVN that is reciprocal to that of FSHbeta. Competitive reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of total pituitary follistatin mRNA revealed no significant changes; however, semiquantitative RT-PCR analyses revealed the presence of two follistatin mRNA species, one of which, corresponding to follistatin-288, was developmentally regulated. These studies identified a reciprocal relationship between PVN PACAP and FSHbeta gene expression in maturing rats. We propose that PACAP contributes to the selective regulation of FSHbeta expression during maturation in the male rat, perhaps via regulation of follistatin.
Moore
Joseph P
JP
Division of Endocrinology & Metabolism, Department of Medicine, University of Louisville, Louisville, Kentucky 40202, USA. jpmoor03@louisville.edu
Wilson
Lisa
L
Dalkin
Alan C
AC
Winters
Stephen J
SJ
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary / Q000235:genetics; D005640:Follicle Stimulating Hormone / Q000097:blood; D037201:Follicle Stimulating Hormone, beta Subunit / Q000235:genetics*; D038681:Follistatin / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D007986:Luteinizing Hormone / Q000097:blood; D037101:Luteinizing Hormone, beta Subunit / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000235:genetics*; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D010902:Pituitary Gland / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011966:Receptors, LHRH / Q000235:genetics; D012741:Sexual Maturation / Q000235:genetics*
C495403:Adcyap1 protein, rat; D018076:DNA, Complementary; D037201:Follicle Stimulating Hormone, beta Subunit; D038681:Follistatin; D037101:Luteinizing Hormone, beta Subunit; D009479:Neuropeptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D012333:RNA, Messenger; D011966:Receptors, LHRH; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone