1. Somatostatin is required for masculinization of growth hormone–regulated hepatic gene expression but not of somatic growth
- Author
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Malcolm J. Low, Veronica Otero-Corchon, Albert F. Parlow, Marcelo Rubinstein, José L. Ramírez, Yogesh C. Patel, and Ujendra Kumar
- Subjects
Male ,Pituitary gland ,medicine.medical_specialty ,CIENCIAS MÉDICAS Y DE LA SALUD ,Genotype ,Transcription, Genetic ,Neurociencias ,Hypothalamus ,Biology ,Article ,Hormonas hepáticas ,Mice ,Internal medicine ,medicine ,Animals ,RNA, Messenger ,Receptors, Somatostatin ,Receptor ,Ultradian rhythm ,Mice, Knockout ,Recombination, Genetic ,Sex Characteristics ,Body Weight ,purl.org/becyt/ford/3.1 [https] ,General Medicine ,Growth hormone secretion ,Sexual dimorphism ,Somatostatina ,Medicina Básica ,medicine.anatomical_structure ,Somatostatin ,Endocrinology ,Liver ,Growth Hormone ,Pituitary Gland ,Female ,purl.org/becyt/ford/3 [https] ,Liver function - Abstract
Pulsatile growth hormone (GH) secretion differs between males and females and regulates the sex-specific expression of cytochrome P450s in liver. Sex steroids influence the secretory dynamics of GH, but the neuroendocrine mechanisms have not been conclusively established. Because periventricular hypothalamic somatostatin (SST) expression is greater in males than in females, we generated knockout (Smst-/-) mice to investigate whether SST peptides are necessary for sexually differentiated GH secretion and action. Despite marked increases in nadir and median plasma GH levels in both sexes of Smst-/- compared with Smst+/+ mice, the mutant mice had growth curves identical to their sibling controls and retained a normal sexual dimorphism in weight and length. In contrast, the liver of male Smst-/- mice was feminized, resulting in an identical profile of GH-regulated hepatic mRNAs between male and female mutants. Male Smst-/- mice show higher expression of two SST receptors in the hypothalamus and pituitary than do females. These data indicate that SST is required to masculinize the ultradian GH rhythm by suppressing interpulse GH levels. In the absence of SST, male and female mice exhibit similarly altered plasma GH profiles that eliminate sexually dimorphic liver function but do not affect dimorphic growth. Fil: Low, Malcolm J.. Oregon Health And Science University; Estados Unidos Fil: Otero Corchon, Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Oregon Health And Science University; Estados Unidos Fil: Parlow, Albert. F.. University of California at Los Angeles; Estados Unidos Fil: Ramirez, Jose L.. McGill University; Canadá Fil: Kumar, Ujenda. McGill University; Canadá Fil: Patel, Yogesh C.. McGill University; Canadá Fil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina
- Published
- 2001