Expression of functional luteinising hormone receptor and its messenger ribonucleic acid in bovine cervix: luteinising hormone augmentation of intracellular cyclic AMP, phosphate inositol and cyclooxygenase

Abstract

The effect of luteinising hormone (LH) on bovine cervical tissues from three phases of the estrous cycle was studied. It was found that in the luteal phase cervix contained an LH receptor mRNA transcript and the 93 kDa LH receptor protein. Incubation of cervical minces from luteal phase with LH significantly increased (P < 0.05) the intracellular concentrations of LH receptor protein, cAMP, inositol phosphate (IP) and cyclooxygenase as well as the production of prostaglandin (PG) E2 (but not PGF2alpha). In contrast in the pre-oestrus/oestrus or post-ovulatory cervix, the signal for the transcript for LH receptor and the LH receptor protein was significantly lower than luteal cervix (P < 0.05) and the tissue did not respond to LH. We conclude that bovine cervix at luteal phase has high levels of LH receptor mRNA and receptor protein associated with the protein coupled receptor family that mediates cAMP and IP signalling responses. The receptors are coupled to PG synthase and generate cervical PGE2.