Quantitative evaluation of CART-containing cells in urinary bladder of rats with renovascular hypertension

Abstract

Recent biological advances make it possible to discover new peptides associated with hypertension. The cocaine- and amphetamine-regulated transcript (CART) is a known factor in appetite and feeding behaviour. Various lines of evidence suggest that this peptide participates not only in control of feeding behaviour but also in the regulation of the cardiovascular and sympathetic systems and blood pressure. The role of CART in blood pressure regulation led us to undertake a study aimed at analysing quantitative changes in CART-containing cells in urinary bladders (UB) of rats with renovascular hypertension. We used the Goldblatt model of arterial hypertension (two-kidney, one clip) to evaluate quantitative changes. This model provides researchers with a commonly used tool to analyse the renin-angiotensin system of blood pressure control and, eventually, to develop drugs for the treatment of chronic hypertension. The study was performed on sections of urinary bladders of rats after 3-, 14-, 28-, 42 and 91 days from hypertension induction. Immunohistochemical identification of CART cells was performed on paraffin for the UBs of all the study animals. CART was detected in the endocrine cells, especially numerous in the submucosa and muscularis layers, with a few found in the transitional epithelium and only occasionally in serosa. Hypertension significantly increased the number of CART-positive cells in the rat UBs. After 3 and 42 days following the procedure, statistically significantly higher numbers of CART-positive cells were identified in comparison with the control animals. The differences between the hypertensive rats and the control animals concerned not only the number density of CART-immunoreactive cells but also their localization. After a 6-week period, each of the rats subjected to the renal artery clipping procedure developed stable hypertension. CART appeared in numerous transitional epithelium cells.As this study provides novel findings, the question appears about the type of connection between hypertension and the functioning and activity of CART in the urinary tract (UT). The study gives rise to the assumption that high blood pressure can be a factor that intensifies CART secretion. In conclusion, the endocrine system of the urinary tract is modified by renovascular hypertension. This may affect the production of hormones and biologically active substances and contribute to the development of possible hypertension complications. In order to fully comprehend the role of the CART peptide in blood pressure regulation, further analyses are necessary.

Cocaine- and amphetamine-regulated transcript (CART) peptide in the enteric nervous system of the porcine esophagus

“…During the present investigation, CART-immunoreactive neurons have been noted in both types of enteric plexuses within all studied fragments of the esophagus. Till now, the presence of this peptide has been noted in various parts of the peripheral nervous system, such as innervation of gall bladder, urinary bladder, pelvic ganglia, dorsal root ganglia, and many others [29][30][31]. The presence of CART has been also investigated in the GI tract of a wide range of mammal species, including humans [14,23,25].…”

Polish Journal of Veterinary Sciences

“…Studies confirm that the administration of recombinant CART peptide into the right lateral ventricle of the hypothalamus leads to a large decrease in food intake in both lean and obese rats (Larsen et al 2000). Recent studies show that high blood pressure can be a factor that increases CART secretion (Janiuk and Kasacka 2015). In rats with simultaneously stimulated D1 and D2 dopamine receptors intracucumbal injection of CART reduced the effects of psychostimulants (Moffett et al 2011).…”

“…Cocaine-and amphetamine-regulated transcript (CART) has been analyzed for over 20 years. First, CART mRNA was identified in the rats striatum (Douglass et al 1995), and further research has shown that CART peptide is present throughout various regions of the central nervous system (CNS) (Douglass et al 1995, Smith et al 1997, Larsen et al 2003, Fagergren and Hurd 2007, Hubert et al 2008), enteric nervous system (ENS) (Zacharko--Siembida and Arciszewski 2014), peripheral nervous system (PNS) (Zacharko-Siembida and Arciszewski 2014, , Radzimirska et al 2016) and cells in the urinary bladder (Janiuk and Kasacka 2015). The presence of CART in the dense core vesicles of synaptic terminals implies that this peptide acts as a neurotransmitter and/or neuromodulator (Smith et al 1997) and coexists with other biologically active substances (Smith et al 1997, Radzimirska et al 2016.…”

Histochemistry in biology and medicine: a message from the citing journals

“…Looking at the distribution of articles on these subjects during the last five years ( Figure 2 ) may help to understand how the interests of this journal’s authors changed over time, particularly in the most recent time. The articles in Pathology & Experimental Medicine ranged from more than 40% to about 20%, having been very numerous in 2013, 5-15 while progressively decreasing in 2014 16-29 and 2015; 30-40 ; most of these papers were focused on the detection of tumor markers, 11 , 12 , 14 , 16 , 18 , 21 , 23 , 28 , 34 but several were aimed at elucidating the mechanisms of carcinogenesis and tumor progression. 7 , 10 , 13 , 26 , 29 , 33 There was steady interest for developmental investigations and stem cell biology with about 15% of the published articles in the last couple of years: molecular markers of cell differentiation were used to describe the process of placenta formation 41 , 42 and organogenesis, 43-46 and to phenotype stem cells.…”