VASCULAR ZONING IN THE ADRENAL CORTEX OF THE NORMAL AND HYPOPHYSECTOMIZED RAT WITH OBSERVATIONS ON THE DISTRIBUTION OF LIPIDS

Abstract

Within the adrenocortical capillary pattern demonstrated by intravitam injection of Indian ink, a zoning into three concentric areas is apparent: (1) an outer injected zone comprising the capillaries of the z. glomerulosa; (2) an intermediate z. lucida of poorly-filled capillaries, corresponding to the 'z. intermedia' (see text, p. 134) plus a variable width of the outer z. fasciculata; (3) an inner injected zone comprising capillaries in the z. reticularis and inner z. fasciculata. A close correspondence in extent was found by various measurements between the z. glomerulosa, the outer injected zone and the outer sudanophil zone of lipid-stained preparations. A zone described as the 'z. lucida' (see text, p. 138) is more extensive than the sudanophobic zone. Following hypophysectomy: (a) The z. intermedia and the sudanophobic zone show a linear increase in extent with time. (b) The z. glomerulosa increases in width up to the 5th week, but thereafter decreases to reach a steady state. (c) Shrinkage, principally of the inner two cortical cellular zones, results in a closer approximation and narrowing of capillaries. With time there is a general reduction in the number and size of cortical capillaries throughout the cortex. (d) Normal vascular zoning in the cortex is apparent for about 3 weeks.