Nerve fibres in the uterine artery increase in number in pregnant guinea-pigs.
Perivascular nerves of the uterine artery were studied in four-month-old pregnant and non-pregnant guinea-pigs. In pregnancy, the uterine artery hypertrophies (more than two-fold growth in diameter and length and 50% increase in wall thickness), but its density of innervation remains high, because of the growth of many new axons. The axons in a complete transverse section of the vessel increase by 40%. The nerve bundles grow by 100%. Small nerve bundles increase more than large bundles: nearly 70% of the nerve bundles contain 10 or fewer axons in pregnant guinea-pigs (37% in non-pregnant animals). The increase in axon number is accompanied by formation of new varicosities, hence presumably of new neuromuscular junctions.
Mione
M C
MC
Department of Anatomy and Developmental Biology, University College London, UK.
Gabella
G
G
D000818:Animals; D001158:Arteries / Q000294:innervation*; D001369:Axons / Q000648:ultrastructure; D002452:Cell Count; D005260:Female; D006168:Guinea Pigs; D006984:Hypertrophy; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D014599:Uterus / Q000098:blood supply*