Investigation of pregnancy induced adrenergic denervation in the rat PhD Thesis

The pregnancy-induced rapid degeneration of the adrenergic nerves innervating the uterus is a well-known but poorly under-stood phenomenon. Since most of the published investigations were carried out by histological assay, our aim was to describethe loss of the adrenergic function during pregnancy and the reinnervational procedure in the postpartum period. Myometrialand cervical samples from rats were loaded with[H]noradrenaline and then transferred into a chamber for superfusion. Aftera wash-out period, fractions were collected. The fifth and fifteenth fraction tissues were stimulated with an electric field. The[H]noradrenaline contents of the fractions were determined, together with the amount remaining in the tissue. The myome-trial [H]noradrenaline release was substantially decreased in early pregnancy, and absent in the late stage. Differences inrelease profile were detected between the implantation sites and the interimplantation areas. As a refinement of the results ofprevious histochemical studies, the noradrenergic functions of the cervix were found to be deeply affected in the early post-partum period. The pregnancy-induced denervational procedure can be followed by means of a superfusional technique after[H]noradrenaline loading. As our technique is considered to be similar in sensitivity to histological methods, superfusion canbe regarded as a model for functional investigations of pregnancy-induced denervation.Reproduction (2005) 130 743–749