Preliminary evaluation of an ELISA kit for the detection of Aldosterone concentration in dog’s urine

Aldosterone is a corticosteroid hormone that plays a pivotal role in homeostatic regulation of water and salt reabsorption, blood volume and pressure. Aldosterone levels tent to rise in humans in hypertension, chronic and acute congestive heart failure (CHF); detrimental effects are opposed by drugs like ACE inhibitors and anti-mineralocorticoid. Aldosterone has a pulsatile secretion, so measurement in serum is less indicative than in urine, where concentration can be indexed to creatinine ratio for estimation of the 24-h aldosterone excretion.Few studies have evaluated aldosterone in canine urine patients, and none by ELISA. Aim of the study was to evaluate a commercial ELISA kit for measuring aldosterone in dog’s urine.Urine was collectedby free catchfrom four dogs. Two were healthy, one was affected by CHF and prescribed anti-mineralocorticoiddaily, one was affected by chronic kidney disease (CKD). Urine was centrifuged (1250g/5 min) and supernatant frozen (-20°C). Aldosterone was measured by a competitive ELISA previously validated for dogs. Twenty-four hours acid hydrolysis was performed on urinary samples before assay.The ELISA standard curve in a semi-log plot was linear between 2.5 and 3.9 ng/mL. Spike-and-recovery, linearity-of-dilution and parallelism experiments showed accuracy inmeasuring aldosterone in dog urine samples. The intra-assay coefficient of variation showed good reproducibility of the assay.Urinary samples are easy to collect, and the ELISA used in this preliminary study seems promising in determining aldosterone in dog urine. Its levels can be of great diagnostic and prognostic value for dogs affected by acute and chronic CHF, in order to assess the best therapeutic strategy. This preliminary analysis will be followed by further studies in patients affected by acute and chronic CHF

Interazioni proteina-proteina: studio delle specifiche interazioni tra ormone della crescita e immunoglobuline e tra fattori di crescita insulino simili e le rispettive proteine di legame

Tesi di dottorato in biochimica. 6. ciclo. A.a. 1994-95Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - Piazza Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Anti-Müllerian hormone receptor type 2 is expressed in gonadotrophs of postpubertal heifers to control gonadotrophin secretion

Preantral and small antral follicles may secret anti-Müllerian hormone (AMH) to control gonadotrophin secretion from ruminant gonadotrophs. The present study investigated whether the main receptor for AMH, AMH receptor type 2 (AMHR2), is expressed in gonadotrophs of postpubertal heifers to control gonadotrophin secretion. Expression of AMHR2 mRNA was detected in anterior pituitaries (APs) of postpubertal heifers using reverse transcription–polymerase chain reaction. An anti-AMHR2 chicken antibody was developed against the extracellular region near the N-terminus of bovine AMHR2. Western blotting using this antibody detected the expression of AMHR2 protein in APs. Immunofluorescence microscopy using the same antibody visualised colocalisation of AMHR2 with gonadotrophin-releasing hormone (GnRH) receptor on the plasma membrane of gonadotrophs. AP cells were cultured for 3.5 days and then treated with increasing concentrations (0, 1, 10, 100, or 1000 pg mL−1) of AMH. AMH (10–1000 pg mL−1) stimulated (P &lt; 0.05) basal FSH secretion. In addition, AMH (100–1000 pg mL−1) weakly stimulated (P &lt; 0.05) basal LH secretion. AMH (100–1000 pg mL−1) inhibited GnRH-induced FSH secretion, but not GnRH-induced LH secretion, in AP cells. In conclusion, AMHR2 is expressed in gonadotrophs of postpubertal heifers to control gonadotrophin secretion.</jats:p

Aldosterone-progesterone relationship in sexually intact Chihuahua bitches

Abstract Background Aldosterone represents an important target of heart failure therapy and may be a valuable indicator of the renin-angiotensin-aldosterone system activity. However, its assessment might be challenging because of the effect of individual factors. In a recent study, intact female dogs showed the highest value of urinary aldosterone-to-creatinine ratio (UAldo:C) compared to other sex categories. In humans and rodents, an influence of progesterone has been reported by several studies. To our knowledge, the relationship between aldosterone and progesterone has not yet been investigated in dogs. The aim of this prospective study was to investigate this relationship in sexually intact Chihuahua females, measuring both hormones twice in the same bitch, that is in anoestrus when progesterone concentrations are baseline and in dioestrus when they are high. Results The study population consisted of 14 sexually intact Chihuahua bitches. Serum progesterone (34.06 (21.17–44.90) vs. 0.19 [0.13–0.38] ng/ml; P < 0.001) and urinary aldosterone (9886.98 ± 5735.22 vs. 5005.72 ± 2127.73 pg/ml; P = 0.01) were significantly higher in dioestrus compared to anoestrous. Urinary aldosterone-to-creatinine ratio was higher in dioestrus compared to anoestrus (4.16 [3.17–6.80] vs. 3.39 ± 1.64 µg/g), but it did not reach the statistical significance (P = 0.056). Serum progesterone showed a moderate positive correlation with urinary aldosterone (ρ = 0.638, P < 0.001) and UAldo:C (ρ = 0.516, P = 0.005). Conclusions The results of the present study suggest the existence of a progesterone-aldosterone relationship in canine species, indicating that sex and phase of reproductive cycle should be taken into account when interpreting aldosterone concentrations. Further studies are needed to confirm these results on a larger canine population and to identify the underlying mechanisms in this species

Signs of Anxiety and Salivary Copeptin Levels in Dogs Diagnosed with Separation-Related Problems in a Short Separation Test

The need for faster diagnosis and more accurate treatment decisions in separation-related problems (SRPs) in dogs is urgent, and a more precise behavioral phenotyping and the development of biomarkers may be of great value. Vasopressin could be a potential non-invasive biomarker of anxiety in dogs with SRPs, but reliable measurement of its concentration is challenging. Here, we compared the behavior and salivary concentrations of copeptin, an arginine vasopressin surrogate, in dogs with SRPs (Case group, n = 13) and with no problems (Control group, n = 15) as they were introduced to a novel environment and subjected to a short episode of separation and reunion with the owner. Dogs in the Case group had greater odds of showing locomotory or oral behaviors during the pre- and post-separation than Controls, while the odds were significantly lower during separation. They also had greater odds of being persistent in seeking attention and proximity from the stranger during reunion. Overall, dogs with SRPs were more likely to express an anxiety-like state during the entire test than Controls, with separation from the owner, and even its anticipation, possibly accounting for this group difference. Although salivary copeptin concentrations did not differ between the two groups, a different trend was detected in Cases and Controls that is worth exploring in further validation studies involving a larger sample