Fluorescence Microscopical Studies on Noradrenaline in the Peripheral Blood Vessels of Spontaneously Hypertensive Rats

抄録

Adrenergic innervations of the peripheral blood vessels of the Spontaneously Hypertensive Rats (OKAMOTO and AOKI) (SHR) were studied by the highly specific and sensitive fluorescence method, in comparison with those of normotensive control rats, and the following results were obtained. 1) Anterior cerebral and middle cerebral arteries over 1 50/h in diameter showed slightly augmented fluorescence in adrenergic nerve terminals in the SHR, but in those less than 150μ in diameter there was no obvious difference in fluorescence between the SHR and controls. 2) Other main cerebral arteries and their branches exhibited the similar distribution of adrenergic innervations and apparent difference in fluorescence was not seen. The more the main cerebral arteries branched out to the distal the more scanty became the tendency in fluorescence distributions, and there was no specific adrenergic fluorescence of the arteries in the intracerebral portion except in the infundibular area. 3) Marked augmented adrenergic fluorescences were seen in the choroidal arteries 50-15μ in diameter in the SHR and granules or cloudlets, called the varicosities of the nerve terminals, were larger than those of controls. 4) The dilated and constricted portions of the intestinal small arteries 100-40μ in diameter in the SHR always revealed augmented fluorescence and granules or cloudlets of fluorescence were larger and more intense than those of controls. 5) The adrenergic fluorescence of small coronary arteries in the SHR was numerous and increased in number. 6) These augmented fluorescences were observed throughout the three stages of hypertension; that is, the prehypertensive, initial, and advanced stages, respectively. 7) The obtained augmented fluorescence in the SHR showed a clear increase in quantity examined by three quantitative methods. 8) Above-mentioned findings suggested that noradrenaline, as the neurotransmitter, of the peripheral blood vessels may accelerate vascular function and play some important roles in the pathogenesis of the SHR.