Markiewicz Włodzimierz, Jaroszewski Jerzy J, Barszczewska Beata, Sienkiewicz Waldemar
Department of Pharmacology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland.
Folia Histochem Cytobiol. 2003;41(2):73-81.
The aim of the present study was to determine: (i) the presence of dopamine-beta-hydroxylase (DbetaH)- and neuropeptide Y (NPY)-immunoreactive (IR) nerve fibres in the wall of the porcine ovarian artery, (ii) the influence of NPY and norepinephrine (NE) on the contractile activity of the pig ovarian arteries, and (iii) the pharmacological analysis of the interaction between NPY and NE in the isolated porcine ovarian arteries collected from immature pigs and from animals in different days of the estrous cycle. Ovarian arteries for immunohistochemistry and isolated arteries for pharmacological studies were excised from immature pigs and mature animals on days 1-5, 8-13 and 17-20 of the estrous cycle. The study showed that both DbetaH- and NPY-IR nerve fibres were present in the pig ovarian arteries in all periods examined, and, that in some fibres DbetaH and NPY were co-localized. Both NE (10(-6) M) and NPY (10(-7) M) increased blood pressure of examined preparations, however, NE caused stronger changes in the vessel wall tension (P<0.001), than did NPY. NE significantly increased (P<0.001) blood pressure of all isolated arteries, however, this response was stronger in vessels from days 1-5 of the cycle, when compared to days 8-13 (P<0.01), 17-20 and immature pigs (P<0.001). NPY increased significantly blood pressure in isolated arteries from days 8-13 and 17-20 of the cycle (P<0.001), while in preparations taken from immature pigs and animals on days 1-5 of the estrous cycle this response was somewhat weaker (P<0.01). A higher elevation (P<0.001) of blood pressure after NPY administration was observed in isolated arteries from days 17-20 of the cycle, when compared to vessels from days 1-5 and 8-13 and those from immature pigs. Moreover, NE significantly intensified (P<0.001) an increase in the blood pressure in isolated arteries pre-treated with NPY in all periods examined. NPY insignificantly (P>0.05) potentiated increase of blood pressure in NE pre-treated vessels of immature pigs and in isolated arteries from days 17-20 of the cycle and significantly (P<0.05) in vessels from days 1-5 and 8-13 of the estrous cycle. Our results indicate that DbetaH- and NPY-IR nerve fibres are present in the pig ovarian arteries. NE and NPY administered alone increased blood pressure in the pig isolated ovarian artery and simultaneous administration of both substances caused each other potentiation of vasocontractile effect, however, the strength of observed changes was dependent on the stage of the estrous cycle.
（i）猪卵巢动脉壁中多巴胺-β-羟化酶（DβH）和神经肽Y（NPY）免疫反应性（IR）神经纤维的存在情况；（ii）NPY和去甲肾上腺素（NE）对猪卵巢动脉收缩活性的影响；（iii）对从未成熟猪以及处于发情周期不同阶段的动物采集的离体猪卵巢动脉中NPY与NE之间相互作用进行药理学分析。从发情周期第1 - 5天、8 - 13天和17 - 20天的未成熟猪和成年动物中切除用于免疫组织化学的卵巢动脉以及用于药理学研究的离体动脉。研究表明，在所有检查时期，猪卵巢动脉中均存在DβH和NPY - IR神经纤维，并且在一些纤维中DβH和NPY共定位。NE（10⁻⁶ M）和NPY（10⁻⁷ M）均可使受试制剂的血压升高，然而，NE引起的血管壁张力变化比NPY更强（P < 0.001）。NE显著升高了所有离体动脉的血压（P < 0.001），然而，与发情周期第8 - 13天（P < 0.01）、17 - 20天以及未成熟猪相比，发情周期第1 - 5天血管的这种反应更强（P < 0.001）。NPY显著升高了发情周期第8 - 13天和17 - 20天离体动脉的血压（P < 0.001），而在未成熟猪以及发情周期第1 - 5天动物的制剂中，这种反应稍弱（P < 0.01）。与发情周期第1 - 5天、8 - 13天以及未成熟猪的血管相比，发情周期第17 - 20天离体动脉在给予NPY后血压升高幅度更大（P < 0.001）。此外，在所有检查时期，NE均显著增强了（P < 0.001）预先用NPY处理的离体动脉的血压升高。NPY对未成熟猪预先用NE处理的血管以及发情周期第17 - 20天离体动脉的血压升高作用不显著（P > 0.05），而对发情周期第1 - 5天和8 - 13天的血管有显著（P < 0.05）增强作用。我们的结果表明，猪卵巢动脉中存在DβH和NPY - IR神经纤维。单独给予NE和NPY可使猪离体卵巢动脉血压升高，同时给予这两种物质会相互增强血管收缩作用，然而，观察到的变化强度取决于发情周期阶段。
