Change particularities of the blood serum levels of vitamin D, calcitonin and parathyroid hormone were analysed in healthy cows of different feeding, age and productivity and in sick cows with metabolic diseases. It was investigated how biochemical indicators vary in cows with metabolic diseases (parturient paresis, osteomalacia and mastitis) and the most informative indicators for diagnostics of these diseases (for levels of calcium, phosphorus and magnesium) were determined. Obtained findings were processed statistically. The method of electrochemiluminescence analysis used for analysis of the blood serum levels of PTH in humans was applied. Compared with radioimmunic method, this method is not expensive and quite fast; in addition, this method is sensitive and reliable, because it permits to detect low levels of PTH in the blood serum (up to 0.127 pmol/l). The method of chemiluminescence immunometric analysis used to find the level of CT in humans was tested. Also the method of immunoferment analysis (ELISA) was tested to measure the blood serum level of 25-OH vitamin D in cattle using human antibodies.

Elevation in serum parathyroid hormone (PTH) often accompanies vitamin D deficiency and renal impairment. PTH elevation in renal failure is viewed as an unfavorable development. Evidence is increasing that PTH elevation may be associated with increased morbidity and mortality. In many instances these PTH effects appear to be independent of vitamin D status. PTH mediates its effects through the ubiquitous type 1 PTH/PTH-related peptide receptor, which is notably present in the cardiovascular system. Increased PTH may promote cardiovascular disease through diminished cardiac contractility, enhanced coronary risk, and cardiac valvular and vascular calcification. High PTH levels appear to be linked to the metabolic syndrome and are aligned with hyperlipidemia, decreased insulin sensitivity, and, perhaps, decreased insulin secretion. Increased PTH also is associated with neuroendocrine activation, increased sympathetic activity, and endothelial stress. The relation between PTH and vitamin D is complex and may show significant threshold variations, especially when calcium intake, age, and race are considered. Moreover, evidence is increasing that fragments of PTH may not only be hormonally active but also may have opposing effects to PTH. Despite these caveats, PTH values provide useful clinical diagnostic and prognostic information in monitoring many chronic ailments such as heart and renal failure and multiple sclerosis.

African Americans have increased risk for cardiovascular and cerebral vascular disease relative to Caucasian Americans. While it is generally accepted that arteries become stiffer at a younger age in African Americans; less is known regarding cerebral vascular function / reactivity (CVMR) to hypercapnia in African Americans. Furthermore, little is known regarding the relationship between arterial stiffness and CVMR, particularly in young healthy adults. We hypothesized that African Americans have stiffer arteries (i.e. arterial stiffness) and reduced CVMR during hypercapnia relative to Caucasian Americans. We also hypothesized that there would be a negative relationship between arterial stiffness and CVMR. Lastly, we hypothesized that these responses would be related to a decrease in Vitamin D status in this population and there would be correlation between Vitamin D status and CVMR. In 11 African American and 19 Caucasian American subjects central arterial stiffness was indexed from carotid-femoral pulse wave velocity (PWV). CVMR was assessed by the cerebral vascular conductance (CVC) response to rebreathing-induced hypercapnia. Vitamin D status was assessed from plasma 25(OH) Vitamin D. PWV was elevated in the African Americans (African American: 581.16 ± 27.7 cm/sec vs. Caucasian American: 502.98 ± 17.6 cm/sec; P < 0.01). CVMR was significantly reduced during hypercapnic rebreathing in the African Americans (African American: 3.05 ± 0.38% of baseline/mmHg vs. Caucasian American: 5.09 ± 0.29% of baseline/mmHg; P < 0.001). When data from all subjects was included there was a trend towards a negative relationship (R = 0.32, P = 0.10) between PWV and CVMR. Vitamin D status was significantly lower in African Americans (African American: 14.96 ± 0.97 ng/ml vs. Caucasian American: 32.73 ± 0.99 ng/ml; P < 0.001); however, there was no significant relationship between Vitamin D status and CVMR (R = 0.23 P = 0.23). In conclusion, these data indicate that African Americans have impaired cerebral vascular responses to hypercapnia, stiffer arteries, and lower Vitamin D status when compared with Caucasian Americans. In addition, there may be a negative relationship between CVMR and PWV; however, no significant correlation between Vitamin D status and vascular function including PWV or CVMR was observed in this study. / text