|Matteri, Robert - Bob|
|Meinersmann, Richard - Rick|
Submitted to: Domestic Animal Endocrinology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2000
Publication Date: 7/1/2000
Citation: LIN, J., BARB, C.R., MATTERI, R.L., KRAELING, R.R., CHEN, X., MEINERSMANN, R.J., RAMPACEK, G.B. LONG FORM LEPTIN RECEPTOR MRNA EXPRESSION IN THE BRAIN, PITUITARY AND OTHERTISSUES IN THE PIG. DOMESTIC ANIMAL ENDOCRINOLOGY. 2000. Interpretive Summary: Inadequate nutrition is characterized by low blood levels of pituitary hormones necessary for growth (growth hormone; GH) and reproductive process (luteinizing hormone; LH). A lack of these hormones results in slow growth, delayed puberty, irregular estrous cycles and failure of animals to breed. The recently discovered protein, leptin, is secreted by fat tissue, serves as a circulating signal nutritional status and regulate body weight, energy expenditure, growth and reproduction. Recent work in the pig demonstrated that leptin inhibited feed intake and stimulated growth hormone release from the pituitary. This is the first report to describe the distribution the functional form of the leptin receptor in the brain, pituitary and other peripheral tissues in the pig. Therefore, understanding the interaction of leptin with its receptor and pituitary hormone secretion is necessary to develop new methods to promote efficient growth and reproduction.
Technical Abstract: Much effort has focused recently on understanding the role of leptin, the obese gene product secreted by adipocytes, in regulating growth and reproduction in rodents, humans and domestic animals. We previously demonstrated that leptin inhibited feed intake and stimulated growth hormone (GH) and luteinizing hormone (LH) secretion in the pig. This study was conducted to determine the location of long form leptin receptor (Ob-R1) mRNA, major for capable of signal transduction, in various tissues of the pig. In the present study, a partial porcine Ob-R1 cDNA, cloned in our laboratory and specific to the intracellular domain, was used to evaluate the Ob-R1 mRNA expression by RT-PCR in the brain and other tissues in three 105 d-old prepuberal gilts and in a 50 d-old fetus. In 105 d-old gilts, Ob-R1 mRNA was expressed in the hypothalamus, cerebral cortex, amygdala, thalamus, cerebellum, area postrema and anterior pituitary. In addition, Ob-R1 mRNA was expressed in ovary, uterine body, liver, kidney, pancreas, adrenal gland, heart, spleen, lung, intestine, bone marrow, muscle and adipose tissue. However, expression was absent in the thyroid, thymus, superior vena cava, aorta, spinal cord, uterine horn and oviduct. In the 50 d-old fetus, Ob-R1 mRNA was expression in brain, intestine, muscle, fat, heart, liver and umbilical cord. These results support the idea that leptin plays a role in regulating numerous physiological functions.