| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Testis |
a Department of Cell Biology, Physiology, and Immunology, University of Córdoba, 14004 Córdoba, Spain
b Departments of Physiology
and
c Medicine, University of Santiago de Compostela, 15705 Santiago de Compostela, Spain
Ghrelin, the endogenous ligand for the growth hormone-secretagogue receptor, is a recently cloned 28-amino acid peptide, expressed primarily in the stomach and hypothalamus, with the ability to stimulate growth hormone (GH) release and food intake. However, the possibility of additional, as yet unknown biological actions of ghrelin has been suggested. As a continuation of our recent findings on the expression and functional role of ghrelin in rat testis, we report here the pattern of cellular expression of ghrelin peptide in rat testis during postnatal development and after selective Leydig cell elimination, and we assess hormonal regulation of testicular ghrelin expression, at the mRNA and/or protein levels, in different experimental models. Immunohistochemical analyses along postnatal development demonstrated selective location of ghrelin peptide within rat testis in mature fetal- and adult-type Leydig cells. In good agreement, ghrelin protein appeared undetectable in testicular interstitium after selective Leydig cell withdrawal. In terms of hormonal regulation, testicular ghrelin mRNA and protein expression decreased to negligible levels after long-term hypophysectomy, whereas replacement with human chorionic gonadotropin (CG) (as superagonist of LH) partially restored ghrelin mRNA and peptide expression. Furthermore, acute administration of human CG (25 IU) to intact rats resulted in a transient increase in testicular ghrelin mRNA levels, with peak values 4 h after injection, an effect that was not mimicked by FSH (12.5 IU/rat). In contrast, testicular expression of ghrelin mRNA remained unaltered in GH-deficient rats, under hyper- and hypothyroidism conditions, as well as in adrenalectomized animals. In conclusion, our results demonstrate that mature Leydig cells are the source of ghrelin expression in rat testis, the protein being expressed in both fetal- and adult-type Leydig cells. In addition, our data indicate that testicular expression of ghrelin is hormonally regulated and is at least partially dependent on pituitary LH.
2 Correspondence: Manuel Tena-Sempere, Physiology Section, Department of Cell Biology, Physiology, and Immunology, Faculty of Medicine, University of Córdoba, Avda. Menéndez Pidal s/n, 14004 Córdoba, Spain. FAX: 34 957 218288; fi1tesem{at}lucano.uco.es
This article has been cited by other articles:
|
|
 |
|
  A. Tropea, F. Tiberi, F. Minici, M. Orlando, M. F. Gangale, F. Romani, F. Miceli, S. Catino, S. Mancuso, M. Sanguinetti, et al. Ghrelin Affects the Release of Luteolytic and Luteotropic Factors in Human Luteal Cells J. Clin. Endocrinol. Metab., August 1, 2007; 92(8): 3239 - 3245. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. M. Seoane, O. Al-Massadi, J. E. Caminos, S. A. Tovar, C. Dieguez, and F. F. Casanueva Sensory Stimuli Directly Acting at the Central Nervous System Regulate Gastric Ghrelin Secretion. An ex Vivo Organ Culture Study Endocrinology, August 1, 2007; 148(8): 3998 - 4006. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Tawadros, L.A. Salamonsen, E. Dimitriadis, and C. Chen Facilitation of decidualization by locally produced ghrelin in the human endometrium Mol. Hum. Reprod., July 1, 2007; 13(7): 483 - 489. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Fernandez-Fernandez, M. Tena-Sempere, J. Roa, J. M. Castellano, V. M Navarro, E. Aguilar, and L. Pinilla Direct stimulatory effect of ghrelin on pituitary release of LH through a nitric oxide-dependent mechanism that is modulated by estrogen Reproduction, June 1, 2007; 133(6): 1223 - 1232. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. C Garcia, M. Lopez, C. V Alvarez, F. Casanueva, M. Tena-Sempere, and C. Dieguez Role of ghrelin in reproduction Reproduction, March 1, 2007; 133(3): 531 - 540. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Ishikawa, H. Fujioka, T. Ishimura, A. Takenaka, and M. Fujisawa Ghrelin Expression in Human Testis and Serum Testosterone Level J Androl, March 1, 2007; 28(2): 320 - 324. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. L Dun, G C. Brailoiu, E. Brailoiu, J. Yang, J. K. Chang, and N. J Dun Distribution and biological activity of obestatin in the rat. J. Endocrinol., November 1, 2006; 191(2): 481 - 489. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. A. Tritos and E. G. Kokkotou The Physiology and Potential Clinical Applications of Ghrelin, a Novel Peptide Hormone Mayo Clin. Proc., May 1, 2006; 81(5): 653 - 660. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Kojima and K. Kangawa Ghrelin: Structure and Function Physiol Rev, April 1, 2005; 85(2): 495 - 522. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. R. Kumar Divide and Differentiate: Ghrelin Instructs the Leydig Cells Endocrinology, November 1, 2004; 145(11): 4822 - 4824. [Full Text] [PDF]
|
|
|
|
|
|
M. L. Barreiro, F. Gaytan, J. M. Castellano, J. S. Suominen, J. Roa, M. Gaytan, E. Aguilar, C. Dieguez, J. Toppari, and M. Tena-Sempere Ghrelin Inhibits the Proliferative Activity of Immature Leydig Cells in Vivo and Regulates Stem Cell Factor Messenger Ribonucleic Acid Expression in Rat Testis Endocrinology, November 1, 2004; 145(11): 4825 - 4834. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. M. Navarro, J. M. Castellano, R. Fernandez-Fernandez, M. L. Barreiro, J. Roa, J. E. Sanchez-Criado, E. Aguilar, C. Dieguez, L. Pinilla, and M. Tena-Sempere Developmental and Hormonally Regulated Messenger Ribonucleic Acid Expression of KiSS-1 and Its Putative Receptor, GPR54, in Rat Hypothalamus and Potent Luteinizing Hormone-Releasing Activity of KiSS-1 Peptide Endocrinology, October 1, 2004; 145(10): 4565 - 4574. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Nogueiras, M. L. Barreiro, J. E. Caminos, F. Gaytan, J. S. Suominen, V. M. Navarro, F. F. Casanueva, E. Aguilar, J. Toppari, C. Dieguez, et al. Novel expression of resistin in rat testis: functional role and regulation by nutritional status and hormonal factors J. Cell Sci., July 1, 2004; 117(15): 3247 - 3257. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Gaytan, M. L. Barreiro, J. E. Caminos, L. K. Chopin, A. C. Herington, C. Morales, L. Pinilla, R. Paniagua, M. Nistal, F. F. Casanueva, et al. Expression of Ghrelin and Its Functional Receptor, the Type 1a Growth Hormone Secretagogue Receptor, in Normal Human Testis and Testicular Tumors J. Clin. Endocrinol. Metab., January 1, 2004; 89(1): 400 - 409. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
U. Pagotto, A. Gambineri, C. Pelusi, S. Genghini, M. Cacciari, B. Otto, T. Castaneda, M. Tschop, and R. Pasquali Testosterone Replacement Therapy Restores Normal Ghrelin in Hypogonadal Men J. Clin. Endocrinol. Metab., September 1, 2003; 88(9): 4139 - 4143. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. E. Caminos, M. Tena-Sempere, F. Gaytan, J. E. Sanchez-Criado, M. L. Barreiro, R. Nogueiras, F. F. Casanueva, E. Aguilar, and C. Dieguez Expression of Ghrelin in the Cyclic and Pregnant Rat Ovary Endocrinology, April 1, 2003; 144(4): 1594 - 1602. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Gaytan, M. L. Barreiro, L. K. Chopin, A. C. Herington, C. Morales, L. Pinilla, F. F. Casanueva, E. Aguilar, C. Dieguez, and M. Tena-Sempere Immunolocalization of Ghrelin and Its Functional Receptor, the Type 1a Growth Hormone Secretagogue Receptor, in the Cyclic Human Ovary J. Clin. Endocrinol. Metab., February 1, 2003; 88(2): 879 - 887. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
