Pseudopregnancy of the bitch in connection to prolactin

Abstract

Pseudocyesis or else pseudopregnancy is a physologicak syndrome in the dog which serves the survival of the canine pack. It conists to symproms similar to postpartum signs like mothering objects, mammary enlargement and even lactation. It was initially hypothesized that pseudopregnancy was caused by increased concentrations of circulating prolactin caused by an abrupt decline of progesterone levels in the late luteal phase and the consequential loss of progesterone negative feedback on prolactin secretion. Due to the prolactin leading role many scientists have condected investigations in order to understand this hormone in depth. Experiments on mice have demonstrated the prolactin secretion pattern during non pregnant healthy, pregnant and pseudopregnant animals. Next trying to comprehend the mechanism of the fluctuating concentration level in pseudopregnant bitches dopamine,a prolactin inhibiting factor was used in a mathematical model that proved PRL rhythm during pseudopregnancy. Apart from the investigation on the importance of increased prolactin secretion also the role in mammogenesis is worth mentioning. Earlier it was hypothesized that the occurance of pseudopregnancy leads to increased chances of canine breast tumour .Something which later was falsified. Last but not least its receptor was also put under the spotlight demonstrating prolactin importance as an upstream mediator in luteal steroid regulation. Pseudopregnancy was also observed after ovariectomy. So in this thesis several research investigations are analysed putting prolactin into the scope and checking its association to pseudopregnancy.