Open AccessHighly suggestive preliminary evidence that the renal interstitium contracts in vivo
Author(s) -
FloresSandoval Omar,
SánchezBriones María Eugenia,
LópezRodríguez Juan F.,
CalvoTurrubiartes Miriam Z.,
LlamazaresAzuara Lilia,
RodríguezMartínez Manuel
Publication year - 2017
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.13328
Subject(s) - bolus (digestion) , medicine , saline , endocrinology , clamp , in vivo , perfusion , kidney , hydrostatic pressure , hormone , contraction (grammar) , biology , mechanical engineering , clamping , physics , microbiology and biotechnology , engineering , thermodynamics
To learn more about controlling renal interstitial hydrostatic pressure ( RIHP ), we assessed its response to renal medullary direct interstitial volume expansion (rm DIVE = 100 μ L bolus infusion/30 sec). Three experimental series (S) were performed in hydropenic, anesthetized, right‐nephrectomized, acute left renal‐denervated and renal perfusion pressure‐controlled rats randomly assigned to groups in each S. S1: Rats without hormonal clamp were contrasted before and after rm DIVE induced via 0.9% saline solution bolus ( SS group) or 2% albumin in SS bolus (2% ALB + SS group). Subcapsular Δ RIHP rose slowly, progressively and similarly in both groups by ~3 mmHg. S2: Rats under hormonal clamp were contrasted before and after sham rm DIVE (time CTR group) and real rm DIVE induced via either SS bolus ( SS group) or SS bolus containing the subcutaneous tissue fibroblast relaxant dibutyryl‐ cAMP ( SS + db‐ cAMP group). Δ RIHP showed time, group, and time*group interaction effects with a biphasic response (early: ~1 mmHg; late: ~4 mmHg) in the SS group that was absent in the SS + db‐ cAMP group. S3: Two groups of rats ( SS and SS + db‐ cAMP ) under hormonal clamp were contrasted as in S2, producing similar Δ RIHP results to those of S2 but showing a slow, progressive, and indistinct decrease in renal outer medullary blood flow in both groups. These results provide highly suggestive preliminary evidence that the renal interstitium is capable of contracting reactively in vivo in response to rm DIVE with SS and demonstrate that such a response is abolished when db‐ cAMP is interstitially and concomitantly infused.