Yunaev M A, Barden J A, Bennett M R
Institute for Biomedical Research, Department of Anatomy and Histology and Department of Physiology, The University of Sydney, NSW 2006, Australia.
J Neurocytol. 2000 Feb;29(2):99-108. doi: 10.1023/a:1007152428481.
Clusters of purinergic receptor subunits, about 1 microm diameter, are found on the smooth muscle cell membrane beneath junctional varicosities in the detrusor muscle of the rat urinary bladder. We have examined the extent of redistribution of the six different subunit clusters, P2X(1) to P2X(6), with respect to junctional varicosities during pregnancy, as it is known that the detrusor muscle undergoes changes in purinergic innervation during this period. Before pregnancy, clusters at junctional varicosities are principally composed of the subtypes P2X(1), P2X(2), P2X(3) and P2X(5). However this subtype distribution changes dramatically during pregnancy, such that by day 14 of pregnancy, the extent of P2X(1), P2X(2), P2X(3) and P2X(5) junctional clusters has decreased by more than 80% whereas the extent of P2X(4) and P2X(6) junctional clusters has increased by more than 80%. These changes were confirmed with Western blots for different subtypes. It is suggested that the changes in the purinergic innervation of the detrusor muscle during pregnancy reflect changes in the P2X subtypes found on the smooth muscle membrane beneath junctional varicosities.
在大鼠膀胱逼尿肌中，直径约1微米的嘌呤能受体亚基簇存在于连接静脉曲张下方的平滑肌细胞膜上。我们研究了在怀孕期间，六种不同亚基簇（P2X(1)至P2X(6)）相对于连接静脉曲张的重新分布程度，因为已知在此期间逼尿肌的嘌呤能神经支配会发生变化。怀孕前，连接静脉曲张处的簇主要由P2X(1)、P2X(2)、P2X(3)和P2X(5)亚型组成。然而，这种亚型分布在怀孕期间发生了巨大变化，以至于在怀孕第14天时，P2X(1)、P2X(2)、P2X(3)和P2X(5)连接簇的程度降低了80%以上，而P2X(4)和P2X(6)连接簇的程度增加了80%以上。这些变化通过针对不同亚型的蛋白质印迹得到了证实。有人认为，怀孕期间逼尿肌嘌呤能神经支配的变化反映了连接静脉曲张下方平滑肌膜上P2X亚型的变化。
