Hemodynamic pressure in glomerular capillaries (GCP) and in first order peritubular capillaries (EAP) in superficial nephrons of mutant Wistar rats with surface glomeruli was measured by micropuncture with a servo nulling device in the following conditions: control; norepinephrine infusion (NE); epinephrine infusion (E); dopamine infusion (D); hemorrhagic hypotension (HH); HH + NE; HH + E; HH + D; acute hypertension secondary to bilateral cervical vagotomy and occlusion of both common carotid arteries. BP was also recorded. Both GCP/BP and EAP/GCP ratios averaged 0.40 in control conditions, but only the EAP/GCP ratio remained constant in all conditions under study, indicating that approximately 60% of the hydrostatic pressure in glomerular capillaries is constantly dissipated by the efferent arteriole. When all values of EAP were plotted against the respective values of GCP, a linear relationship was detected (r = 0.843). These results indicate that changes of pressure in the first order peritubular capillaries of superficial nephrons are merely secondary to changes in glomerular capillary pressure.
|Number of pages||6|
|Publication status||Published - 1976|
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