Chapter Six: Effects of Hormones on Renal Function, part 2
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Calcium and Phosphate Regulation
The regulation of calcim phosphorate requires changes in intestinal, bone and renal function. Unlike sodium and potassium, which are fully absorbed from the intestinal track here, calcium and phosphate are not. Soits, it's one of these kind of interesting things where its this stuff is so important and difficult that it really requires balancing tho three different organ systems. It kind of shows the arbitrariness o when we create these organ systems,. Like these organsistems cross over and communicate and have to interact with each other all the time.
Chapter 6 part 2.
References
Josh touts the PARADIGM-HF Trial Angiotensin–Neprilysin Inhibition versus Enalapril in Heart Failure | NEJM which found this combination was superior to an ARB alone
Joel mentions an early atrial natriuretic peptide trial by Julie Lewis et al. Atrial natriuretic factor in oliguric acute renal failure - American Journal of Kidney Diseases and here’s a metanalysis that put this option to bed: Atrial Natriuretic Peptide for Management of Acute Kidney Injury: A Systematic Review and Meta-analysis
Snack attack? Check out “Snack induced ANP” Snack-Induced Release of Atrial Natriuretic Factor | NEJM
Want more natriuretic peptides than we discussed? Check out this review! Cardiac natriuretic peptides | Nature Reviews Cardiology or this fantastic review: Here’s an excellent review of ANP effect on the kidney: ANP-induced signaling cascade and its implications in renal pathophysiology
Joel mentions the study which probed CRIC cohort regarding NSAIDs. Association of Opioids and Nonsteroidal Anti-inflammatory Drugs With Outcomes in CKD: Findings From the CRIC (Chronic Renal Insufficiency Cohort) Study - American Journal of Kidney Diseases and you may like the discussion on NephJC: No Pain for the Kidneys from NSAIDs — NephJC
The KDIGO guidelines can be found here CKD-Mineral and Bone Disorder (CKD-MBD) – KDIGO
Regulation and Effects of FGF23 in Chronic Kidney Disease
Elegant work on the calcium sensing receptor by Martin Pollak https://doi.org/10.1016/0092-8674(93)90617-Ye
Claudin 14, PTH, and calcium absorption in the loop of Henle: Parathyroid hormone controls paracellular Ca 2+transport in the thick ascending limb by regulating the tight-junction protein Claudin14
Carboxymaltose induced hypophosphatemia by increasing FGF-23. Randomized trial of intravenous iron-induced hypophosphatemia
Current "corrected" calcium concept challenged. | The BMJ
The Dialysis Encephalopathy Syndrome — Possible Aluminum Intoxication | NEJM
NephMadness covered Aluminum binders in 2016.
Roger mentioned the use of ferric citrate as a phosphate binder Ferric Citrate Controls Phosphorus and Delivers Iron in Patients on Dialysis | American Society of Nephrology
Joel reminded us of the misadventures in efforts to normalize hemoglobin, first in hemodialysis patients The Effects of Normal as Compared with Low Hematocrit Values in Patients with Cardiac Disease Who Are Receiving Hemodialysis and Epoetin | NEJM
Later, in patients with CKD, normalization was also not shown to be better: Correction of Anemia with Epoetin Alfa in Chronic Kidney Disease | NEJM , Normalization of Hemoglobin Level in Patients with Chronic Kidney Disease and Anemia | NEJM
A quick shout out for roxadustat and the Nephmadness Anemia region! Roxadustat Treatment for Anemia in Patients Undergoing Long-Term Dialysis | NEJM, #NephMadness 2021: Anemia Region – AJKD Blog
In this review of vasopressin, you can find an excellent discussion of basic stimuli and vasopressin receptors: Vasopressin V1a and V1b Receptors: From Molecules to Physiological Systems | Physiological Reviews
X-Linked Nephrogenic diabetes insipidus is very rare and there was theory that all patients originated from the same family and traveled to the US on the Hopewell ship JCI - X-linked nephrogenic diabetes insipidus mutations in North America and the Hopewell hypothesis. This report describes another family from the Netherlands with nephrogenic DI including the finding that the urine osmolarity never exceeds 200 mOsm/kg. Hereditary Nephrogenic Diabetes Insipidus - GeneReviews® (and here’s a family with central diabetes insipidus https://academic.oup.com/jcem/article/81/1/192/2649423?login=true )
Although we have all learned that thiazides should be used with diabetes insipidus, to induce mild volume depletion, several case reports and animal data have found that acetazolamide might be the best diuretic for the job. Clinicians from Boston Medical Center tried it out in this report: Acetazolamide in Lithium-Induced Nephrogenic Diabetes Insipidus | NEJM based on exciting data in mice! https://jasn.asnjournals.org/content/27/7/2082.short
ADH appears to have an effect on potassium excretion. This was investigated by Giebesch who found, with clearance and micropuncture studies in rats plus isolated perfused tubules, ADH increased potassium secretion Influence of ADH on renal potassium handling: A micropuncture and microperfusion study A corollary should be that inhibition of ADH would increase the risk of hyperkalemia but this was not observed in the SALT-1 and SALT-2 trials. 5% of patients developed hyperkalemia in both the tolvaptan group and the placebo group Tolvaptan, a Selective Oral Vasopressin V2-Receptor Antagonist, for Hyponatremia | NEJM
V1 vasopressin as a pressor Exogenous Vasopressin-Induced Hyponatremia in Patients With Vasodilatory Shock: Two Case Reports and Literature Review
We wondered/debated on our observation that hyponatremia is not reliably seen in patients receiving vasopressin in the ICU. In the VASST trial, Vasopressin versus Norepinephrine Infusion in Patients with Septic Shock, 1 patient in each study arm of nearly 400 patients developed hyponatremia. Note that patients with hyponatremia (<130 mEq/L) were excluded from the study.
Excellent review! Vasopressin and the Regulation of Aquaporin-2
This report looks at the PET scan in individuals who are thirsty. Neuroimaging of genesis and satiation of thirst and an interoceptor-driven theory of origins of primary consciousness
Here’s a little discussion of Dr. Grant Liddle. In addition to his eponymous syndrome, he coined the term “ectopic” and developed the dexamethasone suppression test. Grant Liddle (1921–1989) : The Endocrinologist
This is the sad case of licorice gluttony in NEJM which led to hypokalemia and a cardiac arrest. Case 30-2020: A 54-Year-Old Man with Sudden Cardiac Arrest
In this review of the principal and intercalated cells, check out Figure 8 which has an excellent figure of the aldosterone paradox. https://cjasn.asnjournals.org/content/clinjasn/early/2015/01/30/CJN.08880914.full.pdf?with-ds=yes%3Fversioned%3Dtrue
Remarkably, licorice has been used in dialysis patients to lower potassium in patients in this short term trial. Glycyr-rhetinic acid food supplementation lowers serum potassium concentration in chronic hemodialysis patients
Animal studies on pregnant rats demonstrating the reset osmostat as predicted by Roger. Osmoregulation during Pregnancy in the Rat: EVIDENCE FOR RESETTING OF THE THRESHOLD FOR VASOPRESSIN SECRETION DURING GESTATION
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