The vasopressor system in patients with heart failure due to idiopathic dilated cardiomyopathy--influence of the clinical stage of disease and of chronic drug treatment

Quantitative proteomics reveals TMOD1-related proteins associated with water balance regulation

The distal tubule and collecting duct in kidney regulate water homeostasis. TMOD1 is an actin capping protein that plays an important role in controlling the organization of actin filaments. In this study, we found TMOD1 was specifically expressed in distal tubules and collecting ducts. To investigate the role of TMOD1, we created Tmod1^flox/flox mice and bred them with Ksp-Cre mice to generate tubule-specific Tmod1 knockout mice, Tmod1^flox/flox/Ksp-Cre⁺ (designated as TFK). As compared with control mice, TFK mice showed oliguria, hyperosmolality urine, and high blood pressure. To determine the mechanisms underlying this phenotype, we performed label-free quantitative proteomics on kidneys of TFK and control mice. Total of 83 proteins were found differentially expressed. Bioinformatic analysis indicated that biological processes, including protein phosphorylation and metabolic process, were involved in TMOD1 regulatory network. Gene set enrichment analysis showed that multiple pathways, such as phosphatidylinositol signaling system and GnRH signaling pathway, were strongly associated with Tmod1 knockout. Western blot validated the down-regulation of three proteins, TGFBR2, SLC25A11, and MTFP1, in kidneys of TFK mice. Our study provides valuable information on the molecular functions and the regulatory network of Tmod1 gene in kidney, as well as the new mechanisms for the regulation of water balance.

Vasopressin, cortisol, and catecholamine concentrations in dogs with dilated cardiomyopathy

OBJECTIVE

To evaluate plasma concentrations and urinary excretion of vasopressin and cortisol and urinary excretion of catecholamines in dogs with dilated cardiomyopathy (DCM).

ANIMALS

15 dogs with clinical signs of DCM, 15 dogs with preclinical DCM, and 15 control dogs.

PROCEDURE

Physical examinations, thoracic radiography, ECG, and echocardiography were performed on all dogs. Blood and urine samples were collected.

RESULTS

Plasma concentration of vasopressin and the urine cortisol-to-urine creatinine ratio were significantly increased in dogs with clinical signs of DCM and dogs with preclinical DCM, compared with control dogs. Plasma vasopressin concentration was significantly higher in dogs with clinical signs of DCM, compared with dogs with preclinical DCM. Urine vasopressin-to-urine creatinine ratio was significantly increased in dogs with clinical signs of DCM, compared with dogs with preclinical DCM and control dogs. Urine epinephrine-to-urine creatinine ratio and urine norepinephrine-to-urine creatinine ratio were significantly increased in dogs with clinical signs of DCM, compared with control dogs. Plasma concentration of cortisol and urine dopamine-to-urine creatinine ratio did not differ significantly among groups.

CONCLUSIONS AND CLINICAL RELEVANCE

According to this study, the neuroendocrine pattern is changed in dogs with preclinical DCM. These changes are even more pronounced in dogs with clinical signs of DCM. Analysis of concentrations of vasopressin, cortisol, and catecholamines may aid in identification of the clinical stages of DCM. These findings may also provide a basis for additional studies of the possible beneficial effects of vasopressin antagonists and beta-adrenergic receptor antagonists in the treatment of dogs with congestive heart failure and DCM.

Nocturia, nocturnal polyuria, and sleep quality in the elderly

Nocturia is a common symptom in the elderly, which profoundly influences general health and quality of life. One consequence of nocturia is sleep deterioration, with increased daytime sleepiness and loss of energy and activity. Accidents, e.g., fall injuries, are increased both at night and in the daytime in elderly persons with nocturia. Nocturia is caused by nocturnal polyuria, a reduced bladder capacity, or a combination of the two. Nocturnal polyuria can be caused by numerous diseases, such as diabetes insipidus, diabetes mellitus, congestive heart failure, and sleep apnoea. In the nocturnal polyuria syndrome (NPS), the 24-h diuresis is normal or only slightly increased, while there is a shift in diuresis from daytime to night. NPS is caused by a disturbance of the vasopressin system, with a lack of nocturnal increase in plasma vasopressin or, in some cases, no detectable levels of the hormone at any time of the 24-h period. The calculated prevalence of NPS is about 3% in an elderly population, with no gender difference. In NPS, there are serious sleep disturbances, partly due to the need to get up for micturition, but there is also increased difficulty in falling asleep after nocturnal awakenings and increased sleepiness in the morning. The treatment of NPS may include avoidance of excessive fluid intake, use of diuretics medication in the afternoon rather than the morning, and desmopressin orally at bedtime.

Effects of dilated cardiomyopathy on the renin-angiotensin-aldosterone system, atrial natriuretic peptide activity, and thyroid hormone concentrations in dogs

OBJECTIVE

To evaluate the effect of dilated cardiomyopathy (DCM) on activity of the renin-angiotensin-aldosterone system (RAAS), the N-terminal fragment of proatrial natriuretic peptide (NT-proANP), and thyroid hormone concentrations in dogs.

ANIMALS

15 dogs with clinical signs of DCM, 15 dogs without clinical signs of DCM, and 15 age-, breed-, and sex-matched control dogs.

PROCEDURE

Physical examinations, thoracic radiography, ECG, and echocardiography were performed on all dogs, and blood and urine samples were collected.

RESULTS

Plasma renin activity (PRA), plasma aldosterone concentration (PAC), urine aldosterone-to-creatinine ratio, and NT-proANP concentrations were significantly increased in dogs with clinical signs of DCM, compared with dogs without clinical signs and control dogs. Thyroid-stimulating hormone and total thyroxine concentrations did not differ significantly among groups; however, free thyroxine (FT4) concentrations were significantly decreased in dogs with clinical signs of DCM, compared with control dogs and DCM-dogs without clinical signs. Concentrations of PRA, PAC, FT4, and urine aldosterone-to-creatinine ratio were significantly correlated, whereas plasma concentrations of NT-proANP only correlated with FT4 concentration.

CONCLUSION AND CLINICAL RELEVANCE

In dogs with clinical signs of DCM, increased concentrations of components of the RAAS were associated with increased concentrations of NT-proANP Analysis of the neurohormonal system may aid in identification of clinical stages of DCM for groups of dogs, but the range is too great and there are too many dogs that have neurohormonal concentrations within reference ranges to assess dogs on an individual basis.

Nocturnal polyuria in the elderly person

Aging often disturbs the normal circadian rhythm of urine production. The nocturia commonly seen with aging may result from the loss of nighttime vasopressin production or release that develops by childhood. Restoring the nocturnal increase in vasopressin can have a dramatic clinical response: improved quality of life and less risk of nighttime falls in carefully selected and accurately diagnosed patients.

The nocturnal polyuria syndrome (NPS)

1. The nocturnal polyuria syndrome (NPS) is characterized by an increased nocturnal urine output. The diurnal rhythm in the antidiuretic hormone (ADH) system is absent, and often there is no detectable ADH in the plasma at all during the night. The 24-hr urine output is normal or only moderately increased. Men without nocturnal micturition, normally have a substantial increase in their nocturnal plasma ADH, while those with a need to micturate during the night have the same ADH level at night as in the daytime. Women have lower ADH levels than men, and no nocturnal increase in ADH irrespective of nocturnal voiding. Subjects with an increased nocturnal voiding frequency due to increased nocturnal urine output have an increased thirst, most markedly at night. They often avoid drinking in the evening, but they are unable to resist the impulse to drink during the night. People with polyuria at night wake up often because of the need to void, and accordingly are often tired during the day. 2. An increased nocturnal urine output can be reduced by administration of desmopressin at night. In a short-term study of elderly sufferers from NPS, treated with 20 micrograms desmopressin as nose drops in the evening the nocturnal urine output was reduced from 65 +/- 8% of the 24-hr urine output before treatment to 50 +/- 15% during treatment. In another study elderly with NPS were treated with 40 micrograms desmopressin as an intranasal aerosol in the evening.(ABSTRACT TRUNCATED AT 250 WORDS)