Female Reproductive Tract

Functional and Molecular Characterization of Tachykinins and Tachykinin Receptors in the Mouse Uterus

Abstract
The aim of this study was to analyze the function and expression of tachykinins, tachykinin receptors and neprilysin (NEP) in the mouse uterus. A previous study showed that the uterotonic effects of substance P (SP), neurokinin A (NKA) and neurokinin B (NKB) in estrogen-treated mice were mainly mediated by the tachykinin NK₁ receptor. In the present work further contractility studies were undertaken to determine the nature of the receptors mediating responses to tachykinins in uteri of late pregnant mice. End-point and real-time quantitative RT-PCR were used to analyze the expression of the genes that encode the tachykinins SP/NKA, NKB and hemokinin-1 (HK-1) (Tac1, Tac2 and Tac4); and the genes that encode tachykinin NK₁ (Tacr1), NK₂ (Tacr2) and NK₃ (Tacr3) receptors in uteri from pregnant and non-pregnant mice. The data show that the mRNAs of tachykinins, particularly NKB and HK-1, tachykinin receptors and NEP are locally expressed in the mouse uterus and their expression changes during the estrous cycle and during pregnancy. The tachykinin NK₁ receptor is the predominant tachykinin receptor in the non-pregnant and early pregnant mouse and may mediate tachykinin-induced uterine contractions in the non-pregnant mouse. The tachykinin NK₂ receptor is predominant in the late pregnant mouse and is the main receptor mediating uterotonic responses to tachykinins at late pregnancy. The tachykinin NK₃ receptor is expressed in considerable amounts only in uteri from non-pregnant diestrous animals and its physiological significance remains to be clarified.

Key words: Female Reproductive Tract • Neuroendocrinology • Pregnancy • Signal transduction • Uterus

This article has been cited by other articles:

				M. Aoyama, T. Kawada, M. Fujie, K. Hotta, T. Sakai, T. Sekiguchi, K. Oka, N. Satoh, and H. Satake A Novel Biological Role of Tachykinins as an Up-Regulator of Oocyte Growth: Identification of an Evolutionary Origin of Tachykininergic Functions in the Ovary of the Ascidian, Ciona intestinalis Endocrinology, September 1, 2008; 149(9): 4346 - 4356. [Abstract] [Full Text] [PDF]

				J. N. Pennefather, E. Patak, S. Ziccone, A. Lilley, F. M. Pinto, N. M. Page, M. E. Story, S. Grover, and M. L. Candenas Regulation of the Stimulant Actions of Neurokinin A and Human Hemokinin-1 on the Human Uterus: A Comparison with Histamine Biol Reprod, September 1, 2006; 75(3): 334 - 341. [Abstract] [Full Text] [PDF]

				N.M. Page, J. Dakour, and D.W. Morrish Gene regulation of neurokinin B and its receptor NK3 in late pregnancy and pre-eclampsia Mol. Hum. Reprod., July 1, 2006; 12(7): 427 - 433. [Abstract] [Full Text] [PDF]