TY - JOUR
T1 - Localization of ghrelin and its receptor in the reproductive tract of Holstein heifers
AU - Deaver, S. E.
AU - Hoyer, P. B.
AU - Dial, S. M.
AU - Field, M. E.
AU - Collier, R. J.
AU - Rhoads, M. L.
N1 - Funding Information:
This research project was supported by National Research Initiative Competitive Grant No. 2005-35203-16041 from the USDA Cooperative State Research, Education, and Extension Service.
PY - 2013/1
Y1 - 2013/1
N2 - The aim of this experiment was to localize the mRNA and protein of ghrelin and its active receptor, growth hormone secretagogue 1A (GHS-R1A), within the reproductive tract of dairy cattle. Ghrelin is an orexigenic hormone that has been identified as a potent regulator of energy homeostasis. Recent evidence suggests that ghrelin may also serve as a metabolic signal to the reproductive tract. Ghrelin and GHS-R1A have been identified in the reproductive tract of several species, including humans, mice, and rats. However, ghrelin and GHS-R1A expression have not been described within bovine reproductive tissues. Therefore, the ampulla, isthmus, uterine body, corpus luteum, and follicles were harvested from 3 Holstein heifers (15.91±0.07. mo of age) immediately following exsanguination. Duodenum and hypothalamus were collected as positive controls for ghrelin and GHS-R1A, respectively. Tissues were fixed in 10% formalin and embedded in paraffin for microscopy. Additional samples were stored at -80°C for detection of mRNA. Ghrelin and GHS-R1A mRNA and protein were observed in all tissue types within the reproductive tract of dairy heifers; however, expression appeared to be cell specific. Furthermore, ghrelin protein appeared to be localized to the cytoplasm, whereas GHS-R1A protein was found on the plasma membrane. Within the reproductive tissues, ghrelin mRNA and protein were most abundantly expressed in the ampulla of the oviduct. Concentrations of GHS-R1A were lower than those of ghrelin but differed between tissues. This is one of the first studies to provide molecular evidence for the presence of ghrelin and GHS-R1A within the entire reproductive tract. However, implications for fertility remain to be determined.
AB - The aim of this experiment was to localize the mRNA and protein of ghrelin and its active receptor, growth hormone secretagogue 1A (GHS-R1A), within the reproductive tract of dairy cattle. Ghrelin is an orexigenic hormone that has been identified as a potent regulator of energy homeostasis. Recent evidence suggests that ghrelin may also serve as a metabolic signal to the reproductive tract. Ghrelin and GHS-R1A have been identified in the reproductive tract of several species, including humans, mice, and rats. However, ghrelin and GHS-R1A expression have not been described within bovine reproductive tissues. Therefore, the ampulla, isthmus, uterine body, corpus luteum, and follicles were harvested from 3 Holstein heifers (15.91±0.07. mo of age) immediately following exsanguination. Duodenum and hypothalamus were collected as positive controls for ghrelin and GHS-R1A, respectively. Tissues were fixed in 10% formalin and embedded in paraffin for microscopy. Additional samples were stored at -80°C for detection of mRNA. Ghrelin and GHS-R1A mRNA and protein were observed in all tissue types within the reproductive tract of dairy heifers; however, expression appeared to be cell specific. Furthermore, ghrelin protein appeared to be localized to the cytoplasm, whereas GHS-R1A protein was found on the plasma membrane. Within the reproductive tissues, ghrelin mRNA and protein were most abundantly expressed in the ampulla of the oviduct. Concentrations of GHS-R1A were lower than those of ghrelin but differed between tissues. This is one of the first studies to provide molecular evidence for the presence of ghrelin and GHS-R1A within the entire reproductive tract. However, implications for fertility remain to be determined.
KW - Dairy cattle
KW - Ghrelin
KW - Ghrelin receptor (GHS-R1A)
UR - http://www.scopus.com/inward/record.url?scp=84871607937&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84871607937&partnerID=8YFLogxK
U2 - 10.3168/jds.2012-5506
DO - 10.3168/jds.2012-5506
M3 - Article
C2 - 23141832
AN - SCOPUS:84871607937
SN - 0022-0302
VL - 96
SP - 150
EP - 157
JO - Journal of dairy science
JF - Journal of dairy science
IS - 1
ER -