SENSITISATION OF BLOOD VESSELS TO HYPERTENSIVE DAMAGE BY X IRRADIATION

Journal Article · Sat Mar 18 04:00:00 EST 1961 · Lancet (England)

DOI:https://doi.org/10.1016/S0140-6736(61)92249-8· OSTI ID:4767484

Asscher, A W; Wilson, C; Anson, S G

Investigations were made to test the hypothesis that x radiation increased the susceptibility of the renal arteries to hypertensive damage. A loop of mesentery was irradiated, and, at monthiy intervals thereafter, hypertension was produced by renal artery constriction. The incidence of vascular lesions in the irradiated loop was then compared with that in the remainder of the mesentery in hypertensive animals, and in control animals which were irradiated but were not submitted to renai artery clipping. Doses less than 1000 r did not produce sensitization even after an interval of 4 months. At the higher dosage ievels (1000 and 1200 r), arterial lesions were observed in the mesentery 2 months after irradiation. These were seen only in hypertensive rats, and animals showing no macroscopic lesions at 2 months did not develop them later. The observations were not continued beyond 4 months since with progressive rise in biood pressure, hypertensive lesions begin to appear in nonirradiated tissues at this time. It was concluded, therefore, that 2 months after 1000- or 1200-r x irradiation, the arteriai wall becomes more vulnerable to the damaging effects of increased intravascular pressure. Irradiation may weaken the vessel wall, by structural damage to the endothelium or to the musclefibers of the media, and such vessels may more readily undergo mechanical disruption when the intravascular Pressure rises. It is also possible that irradiation of blood vessels increases their susceptibility to hypertensive damage by exaggerating their myogenic response to variations in intravascular pressure, by reducing the threshoid stimulus at which normal and excessive vasoconstriction occurs. The resulting renai ischemia might then give rise to hypertension in the same way as structural narrowing of the renal arteries. The sequence of events observed after irradiation of the kidneys was consistent with the hypothesis, since the increased susceptibility of the arteries to a rise in intra-arterial pressure was observed 2 months after irradiation, the blood pressure started to rise after about 3-4 months, and arterial necroses developed when hypertension was established at a high level. (H.H.D.)

• Research Organization: London Hospital
• NSA Number: NSA-17-005844
• OSTI ID: 4767484
• Journal Information: Lancet (England), Journal Name: Lancet (England) Vol. Vol: 1; ISSN LANCA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BIOLOGY AND MEDICINE
BLOOD CIRCULATION
BLOOD VESSELS
HYPERTENSION
KIDNEYS
RADIATION DOSES
RADIATION EFFECTS
TISSUES
X RADIATION