Ultrastructural and morphometric studies on the neurohypophysial nerve terminals of the rat following administration of angiotensin II.
The neurohypophysial nerve terminals of rats were studied by electron microscopy and morphometric analysis of vesicles and vacuoles labeled with horseradish peroxidase (HRP) after intraventricular injection of angiotensin II (AII). Exocytotic figures of neurosecretory granules from the nerve terminals were observed. The electron-dense materials resembling the contents of neurosecretory granules were occasionally observed in the extracellular spaces. A highly significant increase in the relative volume occupied by HRP-impregnated structures in the terminals occurred after administration of 500 ng AII. These findings provide morphological evidence for the stimulation of neurohypophysial hormone secretion following administration of 500 ng AII.
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D006735:Horseradish Peroxidase / Q000378:metabolism; D008297:Male; D009411:Nerve Endings / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D010873:Pinocytosis; D010904:Pituitary Gland, Posterior / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D010909:Pituitary Hormones, Posterior / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D010909:Pituitary Hormones, Posterior; D000804:Angiotensin II; D006735:Horseradish Peroxidase