Intrafollicular expression and potential regulatory role of cocaine- and amphetamine-regulated transcript in the ovine ovary

Domest Anim Endocrinol. 2016 Jan:54:30-6. doi: 10.1016/j.domaniend.2015.09.001. Epub 2015 Sep 16.

Abstract

Follicular growth is regulated by a complex interaction of pituitary gonadotropins with local regulatory molecules. Previous studies demonstrated an important role for cocaine- and amphetamine-regulated transcript (CART) in regulation of granulosa cell estradiol production associated with dominant follicle selection in cattle. However, intraovarian expression and actions of CART in other species, including sheep, are not known. The objective of this study was to investigate the expression of CART in sheep follicles and determine the effects of CART on indices of ovine granulosa cell function linked to follicular development. Results demonstrated the expression of CART messenger RNA and prominent intraovarian localization of CART peptide in granulosa cells of sheep follicles. Granulosa cell CART messenger RNA was lower, but follicular fluid estradiol concentrations were higher in large (>5 mm) follicles vs smaller 3- to 5-mm follicles harvested from sheep ovaries of abattoir origin. CART treatment inhibited follicle stimulating hormone-induced estradiol production by cultured ovine granulosal cells and also blocked the follicle stimulating hormone-induced increase in granulosa cell numbers. Results demonstrate expression of CART in sheep follicular tissues and suggest potential biological actions of CART, which are inhibitory to ovine follicular growth and development.

Keywords: CART; Estradiol; Follicle; Granulosal cell; Sheep.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Cell Count
  • Estradiol / analysis
  • Estradiol / biosynthesis
  • Female
  • Follicle Stimulating Hormone / pharmacology
  • Follicular Fluid / chemistry
  • Gene Expression*
  • Granulosa Cells / chemistry
  • Granulosa Cells / drug effects
  • Granulosa Cells / physiology
  • Immunohistochemistry
  • Molecular Sequence Data
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / pharmacology
  • Nerve Tissue Proteins / physiology*
  • Ovarian Follicle / chemistry
  • Ovarian Follicle / growth & development
  • Ovarian Follicle / metabolism*
  • Ovary / chemistry
  • RNA, Messenger / analysis
  • Sequence Homology
  • Sheep / metabolism*

Substances

  • Nerve Tissue Proteins
  • RNA, Messenger
  • cocaine- and amphetamine-regulated transcript protein
  • Estradiol
  • Follicle Stimulating Hormone